emacs/man/idlwave.texi

\input texinfo  @c -*-texinfo-*-
@c %**start of header
@setfilename ../info/idlwave
@settitle IDLWAVE User Manual
@synindex ky cp
@syncodeindex vr cp
@syncodeindex fn cp
@set VERSION 4.15
@set EDITION 4.15
@set IDLVERSION 5.5
@set NSYSROUTINES 1324
@set NSYSKEYWORDS 6129
@set DATE September 2002
@set AUTHOR J.D. Smith & Carsten Dominik
@set AUTHOR-EMAIL dominik@@astro.uva.nl
@set MAINTAINER J.D. Smith
@set MAINTAINER-EMAIL jdsmith@@as.arizona.edu
@set IDLWAVE-HOMEPAGE http://idlwave.org/
@c %**end of header

@copying
This file documents IDLWAVE, a major mode for editing IDL files with
Emacs, and interacting with an IDL shell run as a subprocess.

This is edition @value{EDITION} of the IDLWAVE User Manual for IDLWAVE
@value{VERSION}

Copyright @copyright{} 1999, 2000, 2001, 2002 Free Software Foundation,
Inc.

@quotation
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover texts being ``A GNU
Manual'', and with the Back-Cover Texts as in (a) below.  A copy of the
license is included in the section entitled ``GNU Free Documentation
License'' in the Emacs manual.

(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
this GNU Manual, like GNU software.  Copies published by the Free
Software Foundation raise funds for GNU development.''

This document is part of a collection distributed under the GNU Free
Documentation License.  If you want to distribute this document
separately from the collection, you can do so by adding a copy of the
license to the document, as described in section 6 of the license.
@end quotation
@end copying

@dircategory Emacs
@direntry
* IDLWAVE: (idlwave).	Major mode and shell for IDL files.
@end direntry

@finalout

@titlepage
@title IDLWAVE User Manual
@subtitle Emacs major mode and shell for IDL
@subtitle Edition @value{EDITION}, @value{DATE}

@author by Carsten Dominik & J.D. Smith
@page
This is edition @value{EDITION} of the @cite{IDLWAVE User Manual} for
IDLWAVE version @value{VERSION}, @value{DATE}.
@cindex Copyright, of IDLWAVE
@insertcopying
@end titlepage
@contents

@page

@ifnottex

@node Top, Introduction, (dir), (dir)

IDLWAVE is a package which supports editing source for the
Interactive Data Language (IDL), and running IDL as an inferior
shell.

@end ifnottex

@menu
* Introduction::                What IDLWAVE is and what it's not
* IDLWAVE in a Nutshell::       One page quick-start guide
* Getting Started::             Tutorial
* The IDLWAVE Major Mode::      The mode to edit IDL programs
* The IDLWAVE Shell::           The mode to run IDL as an inferior program
* Installation::                How to Install or Upgrade               
* Acknowledgements::            Who did what
* Sources of Routine Info::     How does IDLWAVE know about routine XYZ     
* Configuration Examples::      The user is king...
* Windows and MacOS::           What still works, and how
* Index::                       Fast access

@detailmenu
 --- The Detailed Node Listing ---

Getting Started (Tutorial)

* Lesson I -- Development Cycle::  
* Lesson II -- Customization::  
* Lesson III -- Library Catalog::  

The IDLWAVE Major Mode

* Code Formatting::             Making code look nice
* Routine Info::                Calling Sequence and Keyword List
* Online Help::                 One key press from source to help
* Completion::                  Completing routine names and Keywords
* Routine Source::              Finding routines, the easy way
* Resolving Routines::          Force the Shell to compile a routine
* Code Templates::              Frequent code constructs
* Abbreviations::               Abbreviations for common commands
* Actions::                     Changing case, Padding, End checking
* Doc Header::                  Inserting a standard header
* Motion Commands::             Moving through the structure of a program
* Misc Options::                Things that fit nowhere else

Code Formatting

* Code Indentation::            Reflecting the logical structure
* Continued Statement Indentation::  
* Comment Indentation::         Special indentation for comment lines
* Continuation Lines::          Splitting statements over lines
* Syntax Highlighting::         Font-lock support
* Octals and Highlighting::     Why "123 causes problems

Completion

* Case of Completed Words::     CaseOFcomPletedWords
* Object Method Completion and Class Ambiguity::  obj->Method, what?
* Object Method Completion in the Shell::  
* Class and Keyword Inheritance::  obj->Method, _EXTRA=e
* Structure Tag Completion::    Completing state.Tag

Actions

* Block Boundary Check::        Is the END statement correct?
* Padding Operators::           Enforcing space around `=' etc
* Case Changes::                Enforcing upper case keywords

The IDLWAVE Shell

* Starting the Shell::          How to launch IDL as a subprocess
* Using the Shell::             Interactively working with the Shell
* Commands Sent to the Shell::  
* Debugging IDL Programs::      
* Examining Variables::         
* Custom Expression Examination::  

Debugging IDL Programs

* Debug Key Bindings::          
* Compiling Programs::          
* Breakpoints and Stepping::    
* Walking the Calling Stack::   

Installation

* Installing IDLWAVE::          How to install the distribution
* Installing Online Help::      Where to get the additional files needed
* Upgrading from idl.el::       Necessary configuration changes

Sources of Routine Info

* Routine Definitions::         Where IDL Routines are defined.
* Routine Information Sources::  So how does IDLWAVE know about...
* Library Catalog::             Scanning the Libraries for Routine Info
* Load-Path Shadows::           Routines defined in several places
* Documentation Scan::          Scanning the IDL Manuals

@end detailmenu
@end menu

@node Introduction, IDLWAVE in a Nutshell, Top, Top
@chapter Introduction
@cindex Introduction
@cindex CORBA (Common Object Request Broker Architecture)
@cindex Interface Definition Language
@cindex Interactive Data Language
@cindex cc-mode.el
@cindex @file{idl.el}
@cindex @file{idl-shell.el}
@cindex Feature overview

IDLWAVE is a package which supports editing source files for the
Interactive Data Language (IDL@footnote{IDL is a registered trademark of
Research Systems, Inc., a Kodak Company}), and for running IDL as an
inferior shell@footnote{Note that this package has nothing to do with
the Interface Definition Language, part of the Common Object Request
Broker Architecture (CORBA)}.  It can also be used for editing source
files for the related WAVE/CL language, but with only limited
support. 

IDLWAVE consists of two main parts: a major mode for editing IDL source
files files (@code{idlwave-mode}) and a mode for running the IDL program
as an inferior shell (@code{idlwave-shell-mode}).  Although one mode can
be used without the other, both work together closely to form a complete
development environment. Here is a brief summary of what IDLWAVE does:

@itemize @bullet
@item 
Code indentation and formatting.
@item
Three level syntax highlighting support.
@item 
Context-sensitive display of calling sequences and keywords for more
than 1000 native IDL routines, extendible to any number of additional
routines in your local IDL libraries.
@item
Routine name space conflict search, likelihood-of-use ranking.
@item
Fast, context-sensitive online help.
@item
Context sensitive completion of routine names and keywords.
@item
Easy insertion of code templates.
@item
Automatic corrections to enforce a variety of customizable coding
standards.
@item
Integrity checks and auto-termination of logical blocks.
@item
Support for @file{imenu} (Emacs) and @file{func-menu} (XEmacs).
@item
Documentation support.
@item
Running IDL as an inferior Shell with history search, command line
editing and all the completion and routine info capabilities present in
IDL source buffers.
@item
Compilation, execution and interactive debugging of programs directly
from the source buffer.
@item
Quick, source-guided navigation of the calling stack, with variable
inspection, etc.
@item
Examining variables and expressions with a mouse click.
@item
And much, much more...
@end itemize

@ifnottex
@cindex Screenshots
Here are a number of screenshots showing IDLWAVE in action:

@itemize @bullet
@item
@uref{http://idlwave.org/screenshots/emacs_21_nav.gif,An IDLWAVE buffer}
@item
@uref{http://idlwave.org/screenshots/emacs_21_keys.gif,A keyword being completed}
@item
@uref{http://idlwave.org/screenshots/emacs_21_help.gif,Online help text.}
@item
@uref{http://idlwave.org/screenshots/emacs_21_ri.gif,Routine information displayed}
@item
@uref{http://idlwave.org/screenshots/emacs_21_bp.gif,Debugging code
stopped at a breakpoint}
@end itemize
@end ifnottex

IDLWAVE is the successor to the @file{idl.el} and @file{idl-shell.el}
files written by Chris Chase.  The modes and files had to be renamed
because of a name space conflict with CORBA's @code{idl-mode}, defined in
Emacs in the file @file{cc-mode.el}.  If you have been using the old
files, check @ref{Upgrading from idl.el} for information on how to
switch.

In this manual, each section ends with a list of related user options.
Don't be confused by the sheer number of options available --- in most
cases the default settings are just fine.  The variables are listed here
to make sure you know where to look if you want to change anything.  For
a full description of what a particular variable does and how to
configure it, see the documentation string of that variable (available
with @kbd{C-h v}).  Some configuration examples are also given in the
appendix.

@node IDLWAVE in a Nutshell, Getting Started, Introduction, Top
@chapter IDLWAVE in a Nutshell
@cindex Summary of important commands
@cindex IDLWAVE in a Nutshell
@cindex Nutshell, IDLWAVE in a

@subheading Editing IDL Programs

@multitable @columnfractions .15 .85
@item @key{TAB}
@tab Indent the current line relative to context.
@item @kbd{C-M-\}
@tab Re-indent all lines in the current region.
@item @kbd{C-u @key{TAB}}
@tab Re-indent all lines in the current statement.
@item @kbd{M-@key{RET}}
@tab Start a continuation line, or split the current line at point.
@item @kbd{M-q}
@tab Fill the current comment paragraph.
@item @kbd{C-c ?}
@tab Display calling sequence and keywords for the procedure or function call
at point.
@item @kbd{M-?}
@tab Load context sensitive online help for nearby routine, keyword, etc.
@item @kbd{M-@key{TAB}}
@tab Complete a procedure name, function name or keyword in the buffer.
@item @kbd{C-c C-i}
@tab Update IDLWAVE's knowledge about functions and procedures.
@item @kbd{C-c C-v}
@tab Visit the source code of a procedure/function.
@item @kbd{C-c C-h}
@tab Insert a standard documentation header.
@item @kbd{C-c @key{RET}}
@tab Insert a new timestamp and history item in the documentation header.
@end multitable

@subheading Running the IDLWAVE Shell, Debugging Programs

@multitable @columnfractions .15 .85
@item @kbd{C-c C-s}
@tab Start IDL as a subprocess and/or switch to the interaction buffer.
@item @kbd{M-p}
@tab Cycle back through IDL command history.
@item @kbd{M-n}
@tab Cycle forward.
@item @kbd{M-@key{TAB}}
@tab Complete a procedure name, function name or keyword in the shell buffer.
@item @kbd{C-c C-d C-c}
@tab Save and compile the source file in the current buffer.
@item @kbd{C-c C-d C-x}
@tab Goto next syntax error.
@item @kbd{C-c C-d C-b}
@tab Set a breakpoint at the nearest viable source line.
@item @kbd{C-c C-d C-d}
@tab Clear the nearest breakpoint.
@item @kbd{C-c C-d C-p}
@tab Print the value of the expression near point in IDL.
@end multitable

@subheading Commonly used Settings in @file{.emacs}
@lisp
;; Change the indentation preferences
(setq idlwave-main-block-indent 2   ; default  0
      idlwave-block-indent 2        ; default  4
      idlwave-end-offset -2)        ; default -4
;; Start autoloading routine info after 2 idle seconds
(setq idlwave-init-rinfo-when-idle-after 2)
;; Pad some operators with spaces
(setq idlwave-do-actions t
      idlwave-surround-by-blank t)
;; Syntax Highlighting
(add-hook 'idlwave-mode-hook 'turn-on-font-lock)
;; Automatically start the shell when needed
(setq idlwave-shell-automatic-start t)
;; Bind debugging commands with CONTROL and SHIFT modifiers
(setq idlwave-shell-debug-modifiers '(control shift))
;; Specify the online help files' location.
(setq idlwave-help-directory "~/.idlwave")
@end lisp

@ifhtml
<A NAME="TUTORIAL"></A>
@end ifhtml
@node Getting Started, The IDLWAVE Major Mode, IDLWAVE in a Nutshell, Top
@chapter Getting Started (Tutorial)
@cindex Quick-Start
@cindex Tutorial
@cindex Getting Started

@menu
* Lesson I -- Development Cycle::  
* Lesson II -- Customization::  
* Lesson III -- Library Catalog::  
@end menu

@node  Lesson I -- Development Cycle, Lesson II -- Customization, Getting Started, Getting Started
@section Lesson I: Development Cycle

The purpose of this tutorial is to guide you through a very basic
development cycle using IDLWAVE.  We will paste a simple program into a
buffer and use the shell to compile, debug and run it.  On the way we
will use many of the important IDLWAVE commands.  Note however that
there are many more capabilities in IDLWAVE than covered here, which can
be discovered by reading the entire manual.

It is assumed that you have access to Emacs or XEmacs with the full
IDLWAVE package including online help (@pxref{Installation}).  We also
assume that you are familiar with Emacs and can read the nomenclature of
key presses in Emacs (in particular, @kbd{C} stands for @key{CONTROL}
and @kbd{M} for @key{META} (often the @key{ALT} key carries this
functionality)).

Open a new source file by typing:

@example
@kbd{C-x C-f tutorial.pro @key{RET}}
@end example

A buffer for this file will pop up, and it should be in IDLWAVE mode, as
shown in the mode line just below the editing window.  Also, the menu
bar should contain entries @samp{IDLWAVE} and @samp{Debug}.

Now cut-and-paste the following code, also available as
@file{tutorial.pro} in the IDLWAVE distribution.

@example
function daynr,d,m,y
  ;; compute a sequence number for a date
  ;; works 1901-2099.
  if y lt 100 then y = y+1900
  if m le 2 then delta = 1 else delta = 0
  m1 = m + delta*12 + 1
  y1 = y * delta
  return, d + floor(m1*30.6)+floor(y1*365.25)+5
end
     
function weekday,day,month,year
  ;; compute weekday number for date
  nr = daynr(day,month,year)
  return, nr mod 7
end
     
pro plot_wday,day,month
  ;; Plot the weekday of a date in the first 10 years of this century.
  years = 2000,+indgen(10)
  wdays = intarr(10)
  for i=0,n_elements(wdays)-1 do begin
      wdays[i] =  weekday(day,month,years[i])
  end
  plot,years,wdays,YS=2,YT="Wday (0=Sunday)"
end
@end example

The indentation probably looks funny, since it's different from the
settings you use, so use the @key{TAB} key in each line to automatically
line it up (or more quickly @emph{select} the entire buffer with
@kbd{C-x h}, and indent the whole region with @kbd{C-M-\}).  Notice how
different syntactical elements are highlighted in different colors, if
you have set up support for font-lock.

Let's check out two particular editing features of IDLWAVE.  Place the
cursor after the @code{end} statement of the @code{for} loop and press
@key{SPC}.  IDLWAVE blinks back to the beginning of the block and
changes the generic @code{end} to the specific @code{endfor}
automatically.  Now place the cursor in any line you would like to split
and press @kbd{M-@key{RET}}.  The line is split at the cursor position,
with the continuation @samp{$} and indentation all taken care of.  Use
@kbd{C-/} to undo the last change.

The procedure @code{plot_wday} is supposed to plot the weekday of a
given date for the first 10 years of the 21st century.  As in most code,
there are a few bugs, which we are going to use IDLWAVE to help us fix.

First, let's launch the IDLWAVE shell.  You do this with the command
@kbd{C-c C-s}.  The Emacs window will split and display IDL running in a
shell interaction buffer.  Type a few commands like @code{print,!PI} to
convince yourself that you can work there just as well as in a terminal,
or the IDLDE.  Use the arrow keys to cycle through your command history.
Are we having fun now?

Now go back to the source window and type @kbd{C-c C-d C-c} to compile
the program.  If you watch the shell buffer, you see that IDLWAVE types
@samp{.run tutorial.pro} for you.  But the compilation fails because
there is a comma in the line @samp{years=...}.  The line with the error
is highlighted and the cursor positioned at the error, so remove the
comma (you should only need to hit @kbd{Delete}!).  Compile again, using
the same keystrokes as before.  Notice that the file is automatically
saved for you.  This time everything should work fine, and you should
see the three routines compile.

Now we want to use the command to plot the day of the week on January
1st.  We could type the full command ourselves, but why do that?  Go
back to the shell window, type @samp{plot_} and hit @key{TAB}.  After a
bit of a delay (while IDLWAVE initializes its routine info database, if
necessary), the window will split to show all procedures it knows
starting with that string, and @w{@code{plot_wday}} should be one of
them.  Saving the buffer alerted IDLWAVE about this new routine.  Click
with the middle mouse button on @code{plot_wday} and it will be copied
to the shell buffer, or if you prefer, add @samp{w} to @samp{plot_} to
make it unambiguous, hit @key{TAB} again, and the full routine name will
be completed.  Now provide the two arguments:

@example
plot_wday,1,1
@end example

and press @key{RET}.  This fails with an error message telling you the
@code{YT} keyword to plot is ambiguous.  What are the allowed keywords
again?  Go back to the source window and put the cursor into the `plot'
line, and press @kbd{C-c ?}.  This shows the routine info window for the
plot routine, which contains a list of keywords, along with the argument
list.  Oh, we wanted @code{YTITLE}.  Fix that up.  Recompile with
@kbd{C-c C-d C-c}. Jump back into the shell with @kbd{C-c C-s}, press
the @key{UP} arrow to recall the previous command and execute again.

This time we get a plot, but it is pretty ugly --- the points are all
connected with a line.  Hmm, isn't there a way for @code{plot} to use
symbols instead?  What was that keyword?  Position the cursor on the
plot line after a comma (where you'd normally type a keyword), and hit
@kbd{M-@key{Tab}}.  A long list of plot's keywords appears.  Aha, there
it is, @code{PSYM}.  Middle click to insert it.  An @samp{=} sign is
included for you too.  Now what were the values of @code{PSYM} supposed
to be?  With the cursor on or after the keyword, press @kbd{M-?} for
online help (alternatively, you could have right clicked on the colored
keyword itself in the completion list).  The online help window will pop
up showing the documentation for the @code{PYSM} keyword.  OK, let's use
diamonds=4.  Fix this, recompile (you know the command by now: @kbd{C-c
C-d C-c}, go back to the shell (if it's vanished, you know the command
to recall it by now: @kbd{C-c C-s}) and execute again.  Now things look
pretty good.

Let's try a different day --- how about April fool's day?

@example
plot_wday,1,4
@end example

Oops, this looks very wrong.  All April fool's days cannot be Fridays!
We've got a bug in the program, perhaps in the @code{daynr} function.
Let's put a breakpoint on the last line there.  Position the cursor on
the @samp{return, d+...} line and press @kbd{C-c C-d C-b}.  IDL sets a
breakpoint (as you see in the shell window), and the line is highlighted
in some way.  Back to the shell buffer, re-execute the previous command.
IDL stops at the line with the breakpoint.  Now hold down the SHIFT key
and click with the middle mouse button on a few variables there:
@samp{d}, @samp{y}, @samp{m}, @samp{y1}, etc.  Maybe @code{d} isn't the
correct type.  CONTROL-SHIFT middle-click on it for help.  Well, it's an
integer, so that's not the problem.  Aha, @samp{y1} is zero, but it
should be the year, depending on delta.  Shift click @samp{delta} to see
that it's 0.  Below, we see the offending line: @samp{y1=y*delta...} the
multiplication should have been a minus sign!  So fix the line to read:

@example
y1 = y - delta
@end example

Now remove all breakpoints: @kbd{C-c C-d C-a}.  Recompile and rerun the
command.  Everything should now work fine.  How about those leap years?
Change the code to plot 100 years and see that every 28 years, the
sequence of weekdays repeats.

@node  Lesson II -- Customization, Lesson III -- Library Catalog, Lesson I -- Development Cycle, Getting Started
@section Lesson II: Customization

Emacs is probably the most customizable piece of software available, and
it would be a shame if you did not make use of this and adapt IDLWAVE to
your own preferences.  Customizing Emacs or IDLWAVE is accomplished by
setting Lisp variables in the @file{.emacs} file in your home directory
--- but do not be dismayed; for the most part, you can just copy and work
from the examples given here.

Let's first use a boolean variable.  These are variables which you turn
on or off, much like a checkbox. A value of @samp{t} means on, a value
of @samp{nil} means off.  Copy the following line into your
@file{.emacs} file, exit and restart Emacs.

@lisp
(setq idlwave-reserved-word-upcase t)
@end lisp

When this option is turned on, each reserved word you type into an IDL
source buffer will be converted to upper case when you press @key{SPC}
or @key{RET} right after the word.  Try it out!  @samp{if} changes to
@samp{IF}, @samp{begin} to @samp{BEGIN}.  If you don't like this
behavior, remove the option again from your @file{.emacs} file.

You likely have your own indentation preferences for IDL code.  For
example, some like to indent the main block of an IDL program from the
margin, different from the conventions used by RSI, and use only 3
spaces as indentation between @code{BEGIN} and @code{END}.  Try the
following lines in @file{.emacs}:

@lisp
(setq idlwave-main-block-indent 2)
(setq idlwave-block-indent 3)
(setq idlwave-end-offset -3)
@end lisp

Restart Emacs, and re-indent the program we developed in the first part
of this tutorial with @kbd{C-c h} and @kbd{C-M-\}.  You may want to keep
these lines in @file{.emacs}, with values adjusted to your likings.  If
you want to get more information about any of these variables, type,
e.g., @kbd{C-h v idlwave-main-block-indent @key{RET}}.  To find which
variables can be customized, look for items marked @samp{User Option:}
throughout this manual.

If you cannot seem to master this Lisp customization in @file{.emacs},
there is another, more user-friendly way to customize all the IDLWAVE
variables.  You can access it through the IDLWAVE menu in one of the
@file{.pro} buffers, menu item @code{Customize->Browse IDLWAVE
Group}. Here you'll be presented with all the various variables grouped
into categories.  You can navigate the hierarchy (e.g. Idlwave Code
Formatting->Idlwave Main Block Indent), read about the variables, change
them, and `Save for Future Sessions'.  Few of these variables need
customization, but you can exercise considerable control over IDLWAVE's
functionality with them.

You may also find the key bindings used for the debugging commands too
long and complicated.  Often we have heard such complaints, ``Do I
really have to type @kbd{C-c C-d C-c} to run a simple command?''  Due to
Emacs rules and conventions, shorter bindings cannot be set by default,
but you can enable them.  First, there is a way to assign all debugging
commands in a single sweep to other combinations.  The only problem is
that we have to use something which Emacs does not need for other
important commands.  One good option is to execute debugging commands by
holding down @key{CONTROL} and @key{SHIFT} while pressing a single
character: @kbd{C-S-b} for setting a breakpoint, @kbd{C-S-c} for
compiling the current source file, @kbd{C-S-a} for deleting all
breakpoints.  You can enable this with:

@lisp
(setq idlwave-shell-debug-modifiers '(shift control))
@end lisp

@noindent If you have a special keyboard with, for example, a
@key{HYPER} key, you could even shorten that:

@lisp
(setq idlwave-shell-debug-modifiers '(hyper))
@end lisp

@noindent to get compilation on @kbd{H-c}.  Often, a modifier key like
@key{HYPER} or @key{SUPER} is bound or can be bound to an otherwise
unused key -- consult your system documentation.

You can also assign specific commands to keys.  This you must do in the
@emph{mode-hook}, a special function which is run when a new buffer gets
set up.  Keybindings can only be done when the buffer exists.  The
possibilities for key customization are endless.  Here we set function
keys f5-f8 to common debugging commands.

@lisp
;; First for the source buffer
(add-hook 'idlwave-mode-hook
   (lambda ()
    (local-set-key [f5] 'idlwave-shell-break-here)
    (local-set-key [f6] 'idlwave-shell-clear-current-bp)
    (local-set-key [f7] 'idlwave-shell-cont)
    (local-set-key [f8] 'idlwave-shell-clear-all-bp)))
;; Then for the shell buffer
(add-hook 'idlwave-shell-mode-hook
   (lambda ()
    (local-set-key [f5] 'idlwave-shell-break-here)
    (local-set-key [f6] 'idlwave-shell-clear-current-bp)
    (local-set-key [f7] 'idlwave-shell-cont)
    (local-set-key [f8] 'idlwave-shell-clear-all-bp)))
@end lisp

@node  Lesson III -- Library Catalog,  , Lesson II -- Customization, Getting Started
@section Lesson III: Library Catalog

We have already used the routine info display in the first part of this
tutorial.  This was the key @kbd{C-c ?} which displays information about 
the IDL routine near the cursor position.  Wouldn't it be nice
to have the same available for your own library routines and for the
huge amount of code in major extension libraries like JHUPL or the
IDL-Astro library?  To do this, you must give IDLWAVE a chance to study
these routines first.  We call this @emph{Building the library catalog}.

From the IDLWAVE entry in the menu bar, select @code{Routine Info/Select
Catalog Directories}.  If necessary, start the shell first with @kbd{C-c
C-s} (@pxref{Starting the Shell}).  IDLWAVE will find out about the IDL
@code{!PATH} variable and offer a list of directories on the path.
Simply select them all (or whichever you want) and click on the
@samp{Scan&Save} button.  Then go for a cup of coffee while IDLWAVE
collects information for each and every IDL routine on your search path.
All this information is written to the file @file{.idlcat} in your home
directory and will from now one be automatically loaded whenever you use
IDLWAVE.  You may find it necessary to rebuild the catalog on occasion
as your local libraries change.  Try to use routine info (@kbd{C-c ?})
or completion (@kbd{M-@key{TAB}}) while on any routine or partial routine
name you know to be located in the library.  E.g., if you have scanned
the IDL-Astro library:

@example
    a=readf@key{M-<TAB>}
@end example


expands to `readfits('.  Then try

@example
    a=readfits(@key{C-c ?}
@end example

and you get:

@example
Usage:    Result = READFITS(filename, header, heap)
...
@end example

I hope you made it until here.  Now you are set to work with IDLWAVE.
On the way you will want to change other things, and to learn more about
the possibilities not discussed in this short tutorial.  Read the
manual, look at the documentation strings of interesting variables (with
@kbd{C-h v idlwave<-variable-name> @key{RET}}) and ask the remaining
questions on the newsgroup @code{comp.lang.idl-pvwave}.

@node The IDLWAVE Major Mode, The IDLWAVE Shell, Getting Started, Top
@chapter The IDLWAVE Major Mode
@cindex IDLWAVE major mode
@cindex Major mode, @code{idlwave-mode}

The IDLWAVE major mode supports editing IDL source files.  In this
chapter we describe the main features of the mode and how to customize
them.

@menu
* Code Formatting::             Making code look nice
* Routine Info::                Calling Sequence and Keyword List
* Online Help::                 One key press from source to help
* Completion::                  Completing routine names and Keywords
* Routine Source::              Finding routines, the easy way
* Resolving Routines::          Force the Shell to compile a routine
* Code Templates::              Frequent code constructs
* Abbreviations::               Abbreviations for common commands
* Actions::                     Changing case, Padding, End checking
* Doc Header::                  Inserting a standard header
* Motion Commands::             Moving through the structure of a program
* Misc Options::                Things that fit nowhere else
@end menu

@node Code Formatting, Routine Info, The IDLWAVE Major Mode, The IDLWAVE Major Mode
@section Code Formatting
@cindex Code formatting
@cindex Formatting, of code

@menu
* Code Indentation::            Reflecting the logical structure
* Continued Statement Indentation::  
* Comment Indentation::         Special indentation for comment lines
* Continuation Lines::          Splitting statements over lines
* Syntax Highlighting::         Font-lock support
* Octals and Highlighting::     Why "123 causes problems
@end menu

The IDL language, with it's early roots in FORTRAN, modern
implementation in C, and liberal borrowing of features of many vector
languages along its 25+ year history, has inherited an unusual mix of
syntax elements.  Left to his or her own devices, a novice IDL
programmer will often conjure code which is very difficult to read and
impossible to adapt.  Much can be gleaned from studying available IDL
code libraries for coding style pointers, but, due to the variety of
IDL syntax elements, replicating this style can be challenging at
best.  Luckily, IDLWAVE understands the structure of IDL code very
well, and takes care of almost all formatting issues for you.  After
configuring it to match your coding standards, you can rely on it to
help keep your code neat and organized.

@cindex Foreign code, adapting
@cindex Indentation, of foreign code
@kindex C-M-\
To re-indent a larger portion of code (e.g. when working with foreign code
written with different conventions), use @kbd{C-M-\}
(@code{indent-region}) after marking the relevant code.  Useful marking
commands are @kbd{C-x h} (the entire file) or @kbd{C-M-h} (the
current subprogram). @xref{Actions}, for information how to impose
additional formatting conventions on foreign code.

@node Code Indentation, Continued Statement Indentation, Code Formatting, Code Formatting
@subsection Code Indentation
@cindex Code indentation
@cindex Indentation

Like all Emacs programming modes, IDLWAVE performs code indentation.
The @key{TAB} key indents the current line relative to context.
@key{LFD} insert a newline and indents the new line.  The indentation is
governed by a number of variables.  IDLWAVE indents blocks (between
@code{PRO}/@code{FUNCTION}/@code{BEGIN} and @code{END}), and
continuation lines.

@defopt idlwave-main-block-indent (@code{0}) 
Extra indentation for the main block of code.  That is the block between
the FUNCTION/PRO statement and the END statement for that program
unit.
@end defopt

@defopt idlwave-block-indent (@code{4})
Extra indentation applied to block lines.  If you change this, you
probably also want to change @code{idlwave-end-offset}.
@end defopt

@defopt idlwave-end-offset (@code{-4})
Extra indentation applied to block END lines.  A value equal to negative
@code{idlwave-block-indent} will make END lines line up with the block
BEGIN lines.
@end defopt

@node Continued Statement Indentation, Comment Indentation, Code Indentation, Code Formatting
@subsection Continued Statement Indentation
@cindex Indentation, continued statement
@cindex Continued statement indentation
Continuation lines (following a line ending with @code{$}) can receive a
fixed indentation offset from the main level, but in several situations
IDLWAVE can use a special form of indentation which aligns continued
statements more naturally.  Special indentation is calculated for
continued routine definition statements and calls, enclosing parentheses
(like function calls, structure/class definitions, explicit structures
or lists, etc.), and continued assignments.  An attempt is made to line
up with the first non-whitespace character after the relevant opening
punctuation mark (@code{,},@code{(},@code{@{},@code{[},@code{=}).  For
lines without any non-comment characters on the line with the opening
punctuation, the continued line(s) are aligned just past the
punctuation.  An example:

@example
function foo, a, b,  $
              c, d
  bar =  sin( a + b + $
              c + d)
end
@end example
@noindent

The only drawback to this special continued statement indentation is
that it consumes more space, e.g., for long function names or left hand
sides of an assignment:

@example
function thisfunctionnameisverylongsoitwillleavelittleroom, a, b, $
                                                            c, d
@end example

You can instruct IDLWAVE when to avoid using this special continuation
indentation by setting the variable
@code{idlwave-max-extra-continuation-indent}, which specifies the
maximum additional indentation beyond the basic indent to be
tolerated, otherwise defaulting to a fixed-offset from the enclosing
indent (the size of which offset is set in
@code{idlwave-continuation-indent}).  Also, since the indentation
level can be somewhat dynamic in continued statements with special
continuation indentation, especially if
@code{idlwave-max-extra-continuation-indent} is small, the key
@kbd{C-u @key{TAB}} will re-indent all lines in the current statement.
Note that @code{idlwave-indent-to-open-paren}, if non-nil, overrides
the @code{idlwave-max-extra-continuation-indent} limit, for
parentheses only, forcing them always to line up.


@defopt idlwave-continuation-indent (@code{2})
Extra indentation applied to normal continuation lines.
@end defopt

@defopt idlwave-max-extra-continuation-indent (@code{20})
The maximum additional indentation (over the basic continuation-indent)
that will be permitted for special continues.  To effectively disable
special continuation indentation, set to @code{0}.  To enable it
constantly, set to a large number (like @code{100}).  Note that the
indentation in a long continued statement never decreases from line to
line, outside of nested parentheses statements.
@end defopt

@defopt idlwave-indent-to-open-paren (@code{t})
Non-@code{nil} means indent continuation lines to innermost open
parenthesis, regardless of whether the
@code{idlwave-max-extra-continuation-indent} limit is satisfied.
@end defopt

@node Comment Indentation, Continuation Lines, Continued Statement Indentation, Code Formatting
@subsection Comment Indentation
@cindex Comment indentation
@cindex Hanging paragraphs
@cindex Paragraphs, filling
@cindex Paragraphs, hanging

In IDL, lines starting with a @samp{;} are called @emph{comment lines}.
Comment lines are indented as follows:

@multitable @columnfractions .1 .90
@item @code{;;;}
@tab The indentation of lines starting with three semicolons remains
unchanged.
@item @code{;;}
@tab Lines starting with two semicolons are indented like the surrounding code.
@item @code{;}
@tab Lines starting with a single semicolon are indented to a minimum column.
@end multitable

@noindent
The indentation of comments starting in column 0 is never changed.

@defopt idlwave-no-change-comment
The indentation of a comment starting with this regexp will not be
changed.
@end defopt

@defopt idlwave-begin-line-comment
A comment anchored at the beginning of line.
@end defopt

@defopt idlwave-code-comment
A comment that starts with this regexp is indented as if it is a part of
IDL code.
@end defopt

@node Continuation Lines, Syntax Highlighting, Comment Indentation, Code Formatting
@subsection Continuation Lines and Filling
@cindex Continuation lines
@cindex Line splitting
@cindex String splitting
@cindex Splitting, of lines

@kindex M-@key{RET}
In IDL, a newline character terminates a statement unless preceded by a
@samp{$}.  If you would like to start a continuation line, use
@kbd{M-@key{RET}}, which calls the command @code{idlwave-split-line}.
It inserts the continuation character @samp{$}, terminates the line and
indents the new line.  The command @kbd{M-@key{RET}} can also be invoked
inside a string to split it at that point, in which case the @samp{+}
concatenation operator is used.

@cindex Filling
@cindex @code{auto-fill-mode}
@cindex Hanging paragraphs
When filling comment paragraphs, IDLWAVE overloads the normal filling
functions and uses a function which creates the hanging paragraphs
customary in IDL routine headers.  When @code{auto-fill-mode} is turned
on (toggle with @kbd{C-c C-a}), comments will be auto-filled.  If the
first line of a paragraph contains a match for
@code{idlwave-hang-indent-regexp} (a dash-space by default), subsequent
lines are positioned to line up after it, as in the following example.

@example
@group
;=================================
; x - an array containing
;     lots of interesting numbers.
;
; y - another variable where
;     a hanging paragraph is used
;     to describe it.
;=================================
@end group
@end example

@kindex M-q
You can also refill a comment at any time paragraph with @kbd{M-q}.
Comment delimiting lines as in the above example, consisting of one or
more @samp{;} followed by one or more of the characters @samp{+=-_*},
are kept in place, as is.

@defopt idlwave-fill-comment-line-only (@code{t})
Non-@code{nil} means auto fill will only operate on comment lines.
@end defopt

@defopt idlwave-auto-fill-split-string (@code{t})
Non-@code{nil} means auto fill will split strings with the IDL @samp{+}
operator.
@end defopt

@defopt idlwave-split-line-string (@code{t})
Non-@code{nil} means @code{idlwave-split-line} will split strings with
@samp{+}.
@end defopt

@defopt idlwave-hanging-indent (@code{t})
Non-@code{nil} means comment paragraphs are indented under the hanging
indent given by @code{idlwave-hang-indent-regexp} match in the first
line of the paragraph.
@end defopt

@defopt idlwave-hang-indent-regexp (@code{"- "})
Regular expression matching the position of the hanging indent
in the first line of a comment paragraph.
@end defopt

@defopt idlwave-use-last-hang-indent (@code{nil})
Non-@code{nil} means use last match on line for
@code{idlwave-indent-regexp}. 
@end defopt

@node Syntax Highlighting, Octals and Highlighting, Continuation Lines, Code Formatting
@subsection Syntax Highlighting
@cindex Syntax highlighting
@cindex Highlighting of syntax
@cindex Font lock

Highlighting of keywords, comments, strings etc. can be accomplished
with @code{font-lock}.  If you are using @code{global-font-lock-mode}
(in Emacs), or have @code{font-lock} turned on in any other buffer in
XEmacs, it should also automatically work in IDLWAVE buffers.  If you'd
prefer invoking font-lock individually by mode, you can enforce it in
@code{idlwave-mode} with the following line in your @file{.emacs}:

@lisp
(add-hook 'idlwave-mode-hook 'turn-on-font-lock)
@end lisp

@noindent IDLWAVE supports 3 increasing levels of syntax highlighting.
The variable @code{font-lock-maximum-decoration} determines which level
is selected.  Individual categories of special tokens can be selected
for highlighting using the variable
@code{idlwave-default-font-lock-items}.

@defopt idlwave-default-font-lock-items
Items which should be fontified on the default fontification level
2. 
@end defopt

@node Octals and Highlighting,  , Syntax Highlighting, Code Formatting
@subsection Octals and Highlighting
@cindex Syntax highlighting, Octals
@cindex Highlighting of syntax, Octals

A rare syntax highlighting problem results from the extremely
unfortunate notation for octal numbers in IDL: @code{"123}.  This
unpaired quotation mark is very difficult to parse, given that it can be
mixed on a single line with any number of strings.  Emacs will
incorrectly identify this as a string, and the highlighting of following
lines of code can be distorted, since the string is never terminated.

One solution to this involves terminating the mistakenly identified
string yourself by providing a closing quotation mark in a comment:

@example
  string("305B) + $ ;" <--- for font-lock
   ' is an Angstrom.'
@end example

@noindent A far better solution is to abandon this notation for octals
altogether, and use the more sensible alternative IDL provides:

@example
   string('305'OB) + ' is an Angstrom.'
@end example

@noindent This simultaneously solves the font-lock problem and is more
consistent with the notation for hexadecimal numbers, e.g. @code{'C5'XB}.

@node Routine Info, Online Help, Code Formatting, The IDLWAVE Major Mode
@section Routine Info
@cindex Routine info
@cindex Updating routine info
@cindex Scanning buffers for routine info
@cindex Buffers, scanning for routine info
@cindex Shell, querying for routine info

@kindex C-c C-i
IDL comes bundled with more than one thousand procedures, functions
and object methods, and large libraries typically contain hundreds or
even thousands more (each with a few to tens of keywords and
arguments).  This large command set can make it difficult to remember
the calling sequence and keywords for the routines you use, but
IDLWAVE can help.  It builds up routine information using a wide
variety of sources: IDLWAVE in fact knows far more about the routines
on your system than IDL itself.  It maintains a list of all built-in
routines, with calling sequences and keywords@footnote{This list is
created by scanning the IDL manuals and might contain (very few)
errors.  Please report any errors to the maintainer, so that they can
be fixed.}.  It also scans Emacs buffers and library files for routine
definitions, and queries the IDLWAVE-Shell for information about
routines currently compiled there.  This information is updated
automatically, and so should usually be current.  To force a global
update and refresh the routine information, use @kbd{C-c C-i}
(@code{idlwave-update-routine-info}).

@kindex C-c ?
To display the information about a routine, press @kbd{C-c ?}, which
calls the command @code{idlwave-routine-info}.  When the current cursor
position is on the name or in the argument list of a procedure or
function, information will be displayed about the routine.  For example,
consider the indicated cursor positions in the following line:

@example
plot,x,alog(x+5*sin(x) + 2),
  |  |   |   |   |  |  |    |
  1  2   3   4   5  6  7    8
@end example

@cindex Default routine, for info and help
On positions 1,2 and 8, information about the @samp{plot} procedure will
be shown.  On positions 3,4, and 7, the @samp{alog} function will be
described, while positions 5 and 6 will investigate the @samp{sin}
function.  

When you ask for routine information about an object method, and the
method exists in several classes, IDLWAVE queries for the class of the
object, unless the class is already known through a text property on the
@samp{->} operator (@pxref{Object Method Completion and Class
Ambiguity}), or by having been explicitly included in the call
(e.g. @code{a->myclass::Foo}).

@cindex Calling sequences
@cindex Keywords of a routine
@cindex Routine source information
The description displayed contains the calling sequence, the list of
keywords and the source location of this routine.  It looks like this:

@example
Usage:    XMANAGER, NAME, ID
Keywords: BACKGROUND CATCH CLEANUP EVENT_HANDLER GROUP_LEADER
          JUST_REG MODAL NO_BLOCK
Source:   SystemLib   [CSB] /soft1/idl53/lib/xmanager.pro
@end example

@cindex Categories, of routines
@cindex Load-path shadows
@cindex Shadows, load-path
@cindex IDL variable @code{!PATH}
@cindex @code{!PATH}, IDL variable
@cindex IDL variable @code{!DIR}
@cindex @code{!DIR}, IDL variable

If a definition of this routine exists in several files accessible to
IDLWAVE, several @samp{Source} lines will point to the different files.
This may indicate that your routine is shadowing a library routine,
which may or may not be what you want (@pxref{Load-Path Shadows}).  The
information about the calling sequence and keywords is derived from the
first source listed.  Library routines are supported only if you have
scanned your local IDL libraries (@pxref{Library Catalog}).  The source
entry consists of a @emph{source category}, a set of @emph{flags} and
the path to the @emph{source file}.  The following categories exist:

@multitable @columnfractions .15 .85
@item @i{System}
@tab A system routine of unknown origin.  When the system library has
been scanned (@pxref{Library Catalog}), this category will automatically
split into the next two.
@item @i{Builtin}
@tab A builtin system routine with no source code available.
@item @i{SystemLib}
@tab A library system routine in the official lib directory @file{!DIR/lib}.
@item @i{Obsolete}
@tab A library routine in the official lib directory @file{!DIR/lib/obsolete}.
@item @i{Library}
@tab A routine in a file on IDL's search path @code{!PATH}.
@item @i{Other}
@tab Any other routine with a file not known to be on the search path.
@item @i{Unresolved}
@tab An otherwise unkown routine the shell lists as unresolved 
(referenced, but not compiled).
@end multitable

You can create additional categories based on the routine's filepath
with the variable @code{idlwave-special-lib-alist}.  This is useful for
easy discrimination of various libraries, or even versions of the same
library.

@cindex Flags, in routine info
@cindex Duplicate routines
@cindex Multiply defined routines
@cindex Routine definitions, multiple
The flags @code{[CSB]} indicate the source of the information IDLWAVE
has regarding the file: from a library catalog (@w{@code{[C--]}},
@pxref{Library Catalog}), from the IDL Shell (@w{@code{[-S-]}}) or from
an Emacs buffer (@w{@code{[--B]}}).  Combinations are possible (a
compiled library routine visited in a buffer might read
@w{@code{[CSB]}}).  If a file contains multiple definitions of the same
routine, the file name will be prefixed with @samp{(Nx)} where @samp{N}
is the number of definitions.

@cindex Online Help from the routine info buffer
@cindex Active text, in routine info
@cindex Inserting keywords, from routine info
@cindex Source file, access from routine info
Some of the text in the @file{*Help*} routine info buffer will be active
(it is highlighted when the mouse moves over it).  Typically, clicking
with the right mouse button invokes online help lookup, and clicking
with the middle mouse button inserts keywords or visits files:

@multitable @columnfractions 0.15 0.85
@item @i{Usage}
@tab If online help is installed, a click with the @emph{right} mouse
button on the @i{Usage:} line will access the help for the
routine (@pxref{Online Help}).  
@item @i{Keyword}
@tab Online help about keywords is also available with the
@emph{right} mouse button.  Clicking on a keyword with the @emph{middle}
mouse button will insert this keyword in the buffer from where
@code{idlwave-routine-info} was called.  Holding down @key{SHIFT} while
clicking also adds the initial @samp{/}.
@item @i{Source}
@tab Clicking with the @emph{middle} mouse button on a @samp{Source} line
finds the source file of the routine and visits it in another window.
Another click on the same line switches back to the buffer from which
@kbd{C-c ?} was called.  If you use the @emph{right} mouse button, the
source will not be visited by a buffer, but displayed in the online help
window.
@item @i{Classes}
@tab The @i{Classes} line is only included in the routine info window if
the current class inherits from other classes.  You can click with the
@emph{middle} mouse button to display routine info about the current
method in other classes on the inheritance chain, if such a method
exists there.
@end multitable

@defopt idlwave-resize-routine-help-window (@code{t})
Non-@code{nil} means resize the Routine-info @file{*Help*} window to
fit the content.
@end defopt

@defopt idlwave-special-lib-alist
Alist of regular expressions matching special library directories.
@end defopt

@defopt idlwave-rinfo-max-source-lines (@code{5})
Maximum number of source files displayed in the Routine Info window.
@end defopt


@node Online Help, Completion, Routine Info, The IDLWAVE Major Mode
@section Online Help

@cindex Online Help
@cindex @file{idlw-help.txt}
@cindex @file{idlw-help.el}
@cindex IDL manual, ASCII version
@cindex Installing online help
@cindex Online Help, Installation
@cindex Speed, of online help
For IDL system routines, RSI provides extensive documentation.  IDLWAVE
can access an ASCII version of this documentation very quickly and
accurately.  This is @emph{much} faster than using the IDL online help
application, because IDLWAVE usually gets you to the right place in the
documentation directly, without any additional browsing and scrolling.
For this online help to work, an ASCII version of the IDL documentation,
which is not part of the standalone IDLWAVE distribution, is required.
The necessary help files can be downloaded from
@uref{@value{IDLWAVE-HOMEPAGE}, the maintainers webpage}.  The text
extracted from the PDF files is fine for normal documentation
paragraphs, but graphics and multiline equations will not be well
formatted.  See also @ref{Documentation Scan}.

@cindex Updated online help
@cindex Online help, updates
@cindex @code{<NEW>..</NEW>}
Occasionally RSI releases a synopsis of new features in an IDL release,
without simultaneously updating the documentation files, instead
preferring a @i{What's New} document which describes the changes.  These
updates are incorporated directly into the IDLWAVE online help, and are
delimited in @code{<NEW>..</NEW>} blocks.

@cindex Source code, as online help
@cindex DocLib header, as online help
For routines which are not documented in the IDL manual (for example
personal or library routines), the source code itself is used as help
text.  If the requested information can be found in a (more or less)
standard DocLib file header, IDLWAVE shows the header (scrolling down to
appropriate keyword).  Otherwise the routine definition statement
(@code{pro}/@code{function}) is shown.

@cindex Structure tags, in online help
@cindex Class tags, in online help
Help is also available for class structure tags (@code{self.TAG}), and
generic structure tags, if structure tag completion is enabled
(@pxref{Structure Tag Completion}).  This is implemented by visiting the
tag within the class or structure definition source itself.  Help is not
available on built-in system class tags.

@kindex M-?
In any IDL program (or, as with most IDLWAVE commands, in the IDL
Shell), press @kbd{M-?} (@code{idlwave-context-help}), or click with
@kbd{S-Mouse-3} to access context sensitive online help.  The following
locations are recognized context for help:

@cindex Context, for online help
@multitable @columnfractions .25 .75
@item @i{Routine name}
@tab The name of a routine (function, procedure, method).
@item @i{Keyword Parameter}
@tab A keyword parameter of a routine.
@item @i{System Variable}
@tab System variables like @code{!DPI}.
@item @i{IDL Statement}
@tab Statements like @code{PRO}, @code{REPEAT}, @code{COMPILE_OPT}, etc.
@item @i{Class name}
@tab A class name in an @code{OBJ_NEW} call.
@item @i{Class Init}
@tab Beyond the class name in an @code{OBJ_NEW} call.
@item @i{Executive Command}
@tab An executive command like @code{.RUN}.  Mostly useful in the shell.
@item @i{Structure Tags}
@tab In structure tags like @code{state.xsize}
@item @i{Structure Tags}
@tab In class tags like @code{self.value}.
@item @i{Default}
@tab The routine that would be selected for routine info display.
@end multitable

@cindex @code{OBJ_NEW}, special online help
Note that the @code{OBJ_NEW} function is special in that the help
displayed depends on the cursor position: If the cursor is on the
@samp{OBJ_NEW}, this function is described.  If it is on the class name
inside the quotes, the documentation for the class is pulled up.  If the
cursor is @emph{after} the class name, anywhere in the argument list,
the documentation for the corresponding @code{Init} method and its
keywords is targeted.

@noindent Apart from source buffers, there are two more places from
which online help can be accessed.

@itemize @bullet
@item
Online help for routines and keywords can be accessed through the
Routine Info display.  Click with @kbd{Mouse-3} on an item to see the
corresponding help (@pxref{Routine Info}).
@item
When using completion and Emacs pops up a @file{*Completions*} buffer
with possible completions, clicking with @kbd{Mouse-3} on a completion
item invokes help on that item (@pxref{Completion}).  Items for which
help is available in the online system documentation (vs. just the
program source itself) will be emphasized (e.g. colored blue).
@end itemize
@noindent
In both cases, a blue face indicates that the item is documented in the
IDL manual, but an attempt will be made to visit non-blue items directly
in the originating source file.

@cindex Help application, key bindings
@cindex Key bindings, in help application
The help window is normally displayed in a separate frame.  The
following commands can be used to navigate inside the help system:

@multitable  @columnfractions .15 .85
@item @kbd{@key{SPACE}}
@tab Scroll forward one page.
@item @kbd{@key{RET}}
@tab Scroll forward one line.
@item @kbd{@key{DEL}}
@tab Scroll back one page.
@item @kbd{n, p}
@tab Browse to the next or previous topic (in physical sequence).
@item @kbd{b, f}
@tab Move back and forward through the help topic history.
@item @kbd{c}
@tab Clear the history.
@item @kbd{Mouse-2}
@tab Follow a link.  Active links are displayed in a different font.
Items under @i{See Also} are active, and classes have links to their
methods and back.
@item @kbd{o}
@tab Open a topic.  The topic can be selected with completion.
@item @kbd{*}
@tab Load the whole help file into Emacs, for global text searches.
@item @kbd{q}
@tab Kill the help window.
@end multitable

@sp 1
@noindent When the help text is a source file, the following commands
are also available:

@multitable  @columnfractions .15 .85
@item @kbd{h}
@tab Jump to DocLib Header of the routine whose source is displayed
as help.
@item @kbd{H}
@tab Jump to the first DocLib Header in the file.
@item @kbd{.} @r{(Dot)}
@tab Jump back and forth between the routine definition (the
@code{pro}/@code{function} statement) and the description of the help
item in the DocLib header.
@item @kbd{F}
@tab Fontify the buffer like source code.  See the variable @code{idlwave-help-fontify-source-code}.
@end multitable

@defopt idlwave-help-directory
The directory where idlw-help.txt and idlw-help.el are stored.
@end defopt

@defopt idlwave-help-use-dedicated-frame (@code{t})
Non-@code{nil} means use a separate frame for Online Help if possible.
@end defopt

@defopt idlwave-help-frame-parameters
The frame parameters for the special Online Help frame.
@end defopt

@defopt idlwave-max-popup-menu-items (@code{20})
Maximum number of items per pane in pop-up menus.
@end defopt

@defopt idlwave-extra-help-function
Function to call for help if the normal help fails.
@end defopt

@defopt idlwave-help-fontify-source-code (@code{nil})
Non-@code{nil} means fontify source code displayed as help.
@end defopt

@defopt idlwave-help-source-try-header (@code{t})
Non-@code{nil} means try to find help in routine header when displaying source
file.
@end defopt

@defopt idlwave-help-link-face
The face for links in IDLWAVE online help.
@end defopt

@defopt idlwave-help-activate-links-aggressively (@code{t})
Non-@code{nil} means make all possible links in help window active.
@end defopt

@node Completion, Routine Source, Online Help, The IDLWAVE Major Mode
@section Completion
@cindex Completion
@cindex Keyword completion
@cindex Method completion
@cindex Object method completion
@cindex Class name completion
@cindex Function name completion
@cindex Procedure name completion

@kindex M-@key{TAB}
@kindex C-c C-i
IDLWAVE offers completion for class names, routine names, keywords,
system variables, class structure tags, regular structure tags and file
names.  As in many programming modes, completion is bound to
@kbd{M-@key{TAB}} (or @kbd{@key{TAB}} in the IDLWAVE Shell ---
@pxref{Using the Shell}).  Completion uses exactly the same internal
information as routine info, so when necessary (rarely) it can be
updated with @kbd{C-c C-i} (@code{idlwave-update-routine-info}).

The completion function is context sensitive and figures out what to
complete based location of the point.  Here are example lines and what
@kbd{M-@key{TAB}} would try to complete when the cursor is on the
position marked with a @samp{_}:

@example
plo_                    @r{Procedure}
x = a_                  @r{Function}
plot,xra_               @r{Keyword of @code{plot} procedure}
plot,x,y,/x_            @r{Keyword of @code{plot} procedure}
plot,min(_              @r{Keyword of @code{min} function}
obj -> a_               @r{Object method (procedure)}
a(2,3) = obj -> a_      @r{Object method (function)}
x = obj_new('IDL_       @r{Class name}
x = obj_new('MyCl',a_   @r{Keyword to @code{Init} method in class @code{MyCl}}
pro A_                  @r{Class name}
pro _                   @r{Fill in @code{Class::} of first method in this file}
!v_                     @r{System variable}
!version.t_             @r{Structure tag of system variable}
self.g_                 @r{Class structure tag in methods}
state.w_                @r{Structure tag, if tag completion enabled}
name = 'a_              @r{File name (default inside quotes)}
@end example

@cindex Completion, ambiguity
@cindex Completion, forcing function name
The only place where completion is ambiguous is procedure/function
@emph{keywords} versus @emph{functions}.  After @samp{plot,x,_}, IDLWAVE
will always assume a keyword to @samp{plot}.  However, a function is
also a possible completion here.  You can force completion of a function
name at such a location by using a prefix arg: @kbd{C-u M-@key{TAB}}.

@cindex Scrolling the @file{*Completions*} window
@cindex Completion, scrolling
@cindex Completion, Online Help
@cindex Online Help in @file{*Completions*} buffer
If the list of completions is too long to fit in the
@file{*Completions*} window, the window can be scrolled by pressing
@kbd{M-@key{TAB}} repeatedly.  Online help (if installed) for each
possible completion is available by clicking with @kbd{Mouse-3} on the
item.  Items for which system online help (from the IDL manual) is
available will be emphasized (e.g. colored blue).  For other items, the
corresponding source code or DocLib header will be used as the help
text.

@cindex Completion, cancelling
@cindex Cancelling completion
Completion is not a blocking operation --- you are free to continue
editing, enter commands, or simply ignore the @file{*Completions*}
buffer during a completion operation.  If, however, the most recent
command was a completion, @kbd{C-g} will remove the buffer and restore
the window configuration.  You can also remove the buffer at any time
with no negative consequences.

@defopt idlwave-keyword-completion-adds-equal (@code{t})
Non-@code{nil} means completion automatically adds @samp{=} after
completed keywords.
@end defopt

@defopt idlwave-function-completion-adds-paren (@code{t})
Non-@code{nil} means completion automatically adds @samp{(} after
completed function.  A value of `2' means also add the closing
parenthesis and position the cursor between the two.
@end defopt

@defopt idlwave-completion-restore-window-configuration (@code{t})
Non-@code{nil} means restore window configuration after successful
completion.
@end defopt

@defopt idlwave-highlight-help-links-in-completion (@code{t})
Non-@code{nil} means highlight completions for which system help is
available.
@end defopt

@menu
* Case of Completed Words::     CaseOFcomPletedWords
* Object Method Completion and Class Ambiguity::  obj->Method, what?
* Object Method Completion in the Shell::  
* Class and Keyword Inheritance::  obj->Method, _EXTRA=e
* Structure Tag Completion::    Completing state.Tag
@end menu

@node  Case of Completed Words, Object Method Completion and Class Ambiguity, Completion, Completion
@subsection Case of Completed Words
@cindex Case of completed words
@cindex Mixed case completion
The case of the completed words is determined by what is already in the
buffer.  When the partial word being completed is all lower case, the
completion will be lower case as well.  If at least one character is
upper case, the string will be completed in upper case or mixed case.
The default is to use upper case for procedures, functions and keywords,
and mixed case for object class names and methods, similar to the
conventions in the IDL manuals.  These defaults can be changed with the
variable @code{idlwave-completion-case}.  For instance, to enable
mixed-case completion for routines in addition to classes and methods,
you need an entry such as @code{routine . preserve} in that variable.
To enable total control over the case of completed items, independent of
buffer context, set @code{idlwave-completion-force-default-case} to
non-@code{nil}.

@defopt idlwave-completion-case
Association list setting the case (UPPER/lower/Capitalized/MixedCase...)
of completed words.
@end defopt

@defopt idlwave-completion-force-default-case (@code{nil})
Non-@code{nil} means completion will always honor the settings in
@code{idlwave-completion-case}.  When nil (the default), entirely lower
case strings will always be completed to lower case, no matter what the
settings in @code{idlwave-completion-case}.
@end defopt

@defopt idlwave-complete-empty-string-as-lower-case (@code{nil})
Non-@code{nil} means the empty string is considered lower case for
completion.
@end defopt

@node  Object Method Completion and Class Ambiguity, Object Method Completion in the Shell, Case of Completed Words, Completion
@subsection Object Method Completion and Class Ambiguity
@cindex Object methods
@cindex Class ambiguity
@cindex @code{self} object, default class
An object method is not uniquely determined without the object's class.
Since the class is almost always omitted in the calling source, IDLWAVE
considers all available methods in all classes as possible method name
completions.  The combined list of keywords of the current method in
@emph{all} known classes which contain that method will be considered
for keyword completion.  In the @file{*Completions*} buffer, the
matching classes will be shown next to each item (see option
@code{idlwave-completion-show-classes}).  As a special case, the class
of an object called @samp{self} is always taken to be the class of the
current routine.  All classes it inherits from are considered as well
where appropriate.

@cindex Forcing class query.
@cindex Class query, forcing
You can also call @code{idlwave-complete} with a prefix arg: @kbd{C-u
M-@key{TAB}}.  IDLWAVE will then prompt you for the class in order to
narrow down the number of possible completions.  The variable
@code{idlwave-query-class} can be configured to make such prompting the
default for all methods (not recommended), or selectively for very
common methods for which the number of completing keywords would be too
large (e.g. @code{Init}).  

@cindex Saving object class on @code{->}
@cindex @code{->}
After you have specified the class for a particular statement (e.g. when
completing the method), IDLWAVE can remember it for the rest of the
editing session.  Subsequent completions in the same statement
(e.g. keywords) can then reuse this class information.  This works by
placing a text property on the method invocation operator @samp{->},
after which the operator will be shown in a different face.  This is not
enabled by default --- the variable @code{idlwave-store-inquired-class}
can be used to turn it on.

@defopt idlwave-completion-show-classes (@code{1})
Non-@code{nil} means show classes in @file{*Completions*} buffer when
completing object methods and keywords.
@end defopt

@defopt idlwave-completion-fontify-classes (@code{t})
Non-@code{nil} means fontify the classes in completions buffer.
@end defopt

@defopt idlwave-query-class (@code{nil})
Association list governing query for object classes during completion.
@end defopt

@defopt idlwave-store-inquired-class (@code{nil})
Non-@code{nil} means store class of a method call as text property on
@samp{->}.
@end defopt

@defopt idlwave-class-arrow-face
Face to highlight object operator arrows @samp{->} which carry a class
text property.
@end defopt

@node Object Method Completion in the Shell, Class and Keyword Inheritance, Object Method Completion and Class Ambiguity, Completion
@subsection Object Method Completion in the Shell
@cindex Method Completion in Shell
In the IDLWAVE Shell (@pxref{The IDLWAVE Shell}), objects on which
methods are being invoked have a special property: they must exist as
variables, and so their class can be determined (for instance, using the
@code{obj_class()} function).  In the Shell, when attempting completion,
routine info, or online help within a method routine, a query is sent to
determine the class of the object.  If this query is successful, the
class found will be used to select appropriate completions, routine
info, or help.  If unsuccessful, information from all known classes will
be used (as in the buffer).  Setting the variable
@code{idlwave-store-inquired-class} can eliminate unnecessary repetitive
queries for the object's class, and speed up completion.

@node   Class and Keyword Inheritance, Structure Tag Completion, Object Method Completion in the Shell, Completion
@subsection Class and Keyword Inheritance
@cindex Inheritance, class
@cindex Keyword inheritance
@cindex Inheritance, keyword

Class inheritance affects which methods are called in IDL.  An object of
a class which inherits methods from one or more superclasses can
override that method by defining its own method of the same name, extend
the method by calling the method(s) of its superclass(es) in its
version, or inherit the method directly by making no modifications.
IDLWAVE examines class definitions during completion and routine
information display, and records all inheritance information it finds.
This information is displayed if appropriate with the calling sequence
for methods (@pxref{Routine Info}), as long as variable
@code{idlwave-support-inheritance} is non-@code{nil}.

In many class methods, @emph{keyword} inheritance (@code{_EXTRA} and
@code{_REF_EXTRA}) is used hand-in-hand with class inheritance and
method overriding.  E.g., in a @code{SetProperty} method, this technique
allows a single call @code{obj->SetProperty} to set properties up the
entire class inheritance chain.  This is often referred to as
@emph{chaining}, and is characterized by chained method calls like
@w{@code{self->MySuperClass::SetProperty,_EXTRA=e}}.

IDLWAVE can accommodate this special synergy between class and keyword
inheritance: if @code{_EXTRA} or @code{_REF_EXTRA} is detected among a
method's keyword parameters, all keywords of superclass versions of the
method being considered are included in completion.  There is of course
no guarantee that this type of keyword chaining actually occurrs, but
for some methods it's a very convenient assumption.  The variable
@code{idlwave-keyword-class-inheritance} can be used to configure which
methods have keyword inheritance treated in this simple, class-driven
way.  By default, only @code{Init} and @code{(Get|Set)Property} are.
The completion buffer will label keywords based on their originating
class.

@defopt idlwave-support-inheritance (@code{t})
Non-@code{nil} means consider inheritance during completion, online help etc.
@end defopt

@defopt idlwave-keyword-class-inheritance 
A list of regular expressions to match methods for which simple
class-driven keyword inheritance will be used for Completion.
@end defopt

@node    Structure Tag Completion,  , Class and Keyword Inheritance, Completion
@subsection Structure Tag Completion
@cindex Completion, structure tag
@cindex Structure tag completion

In many programs, especially those involving widgets, large structures
(e.g. the @samp{state} structure) are used to communicate among
routines.  It is very convenient to be able to complete structure tags,
in the same way as for instance variables (tags) of the @samp{self}
object (@pxref{Object Method Completion and Class Ambiguity}).  Add-in
code for structure tag completion is available in the form of a loadable
completion module: @file{idlw-complete-structtag.el}.  Tag completion in
structures is highly ambiguous (much more so than @samp{self}
completion), so @code{idlw-complete-structtag} makes an unusual and very
specific assumption: the exact same variable name is used to refer to
the structure in all parts of the program.  This is entirely unenforced
by the IDL language, but is a typical convention.  If you consistently
refer to the same structure with the same variable name
(e.g. @samp{state}), structure tags which are read from its definition
in the same file can be used for completion.

Structure tag completion is not enabled by default.  To enable it,
simply add the following to your @file{.emacs}:

@lisp
   (add-hook 'idlwave-load-hook 
             (lambda () (require 'idlw-complete-structtag)))
@end lisp

Once enabled, you'll also be able to access online help on the structure
tags, using the usual methods (@pxref{Online Help}).

@node Routine Source, Resolving Routines, Completion, The IDLWAVE Major Mode
@section Routine Source
@cindex Routine source file
@cindex Module source file
@cindex Source file, of a routine
@kindex C-c C-v
In addition to clicking on a @i{Source:} line in the routine info
window, there is another way to quickly visit the source file of a
routine.  The command @kbd{C-c C-v} (@code{idlwave-find-module}) asks
for a module name, offering the same default as
@code{idlwave-routine-info} would have used, taken from nearby buffer
contents.  In the minibuffer, specify a complete routine name (including
any class part).  IDLWAVE will display the source file in another
window, positioned at the routine in question.

@cindex Buffers, killing
@cindex Killing autoloaded buffers
Since getting the source of a routine into a buffer is so easy with
IDLWAVE, too many buffers visiting different IDL source files are
sometimes created.  The special command @kbd{C-c C-k}
(@code{idlwave-kill-autoloaded-buffers}) can be used to easily remove
these buffers.

@node Resolving Routines, Code Templates, Routine Source, The IDLWAVE Major Mode
@section Resolving Routines
@cindex @code{RESOLVE_ROUTINE}
@cindex Compiling library modules
@cindex Routines, resolving

The key sequence @kbd{C-c =} calls the command @code{idlwave-resolve}
and sends the line @samp{RESOLVE_ROUTINE, '@var{routine_name}'} to IDL
in order to resolve (compile) it.  The default routine to be resolved is
taken from context, but you get a chance to edit it.

@code{idlwave-resolve} is one way to get a library module within reach
of IDLWAVE's routine info collecting functions.  A better way is to
scan (parts of) the library (@pxref{Library Catalog}).  Routine info on
library modules will then be available without the need to compile the
modules first, and even without a running shell.

@xref{Sources of Routine Info}, for more information on the ways IDLWAVE
collects data about routines, and how to update this information.

@node Code Templates, Abbreviations, Resolving Routines, The IDLWAVE Major Mode
@section Code Templates
@cindex Code templates
@cindex Templates

IDLWAVE can insert IDL code templates into the buffer.  For a few
templates, this is done with direct key bindings:

@multitable @columnfractions .15 .85
@item @kbd{C-c C-c}
@tab @code{CASE} statement template
@item @kbd{C-c C-f}
@tab @code{FOR} loop template
@item @kbd{C-c C-r}
@tab @code{REPEAT} loop template
@item @kbd{C-c C-w}
@tab @code{WHILE} loop template
@end multitable

All code templates are also available as abbreviations
(@pxref{Abbreviations}).

@node Abbreviations, Actions, Code Templates, The IDLWAVE Major Mode
@section Abbreviations
@cindex Abbreviations

Special abbreviations exist to enable rapid entry of commonly used
commands.  Emacs abbreviations are expanded by typing text into the
buffer and pressing @key{SPC} or @key{RET}.  The special abbreviations
used to insert code templates all start with a @samp{\} (the backslash),
or, optionally, any other character set in
@code{idlwave-abbrev-start-char}. IDLWAVE ensures that abbreviations are
only expanded where they should be (i.e., not in a string or comment),
and permits the point to be moved after an abbreviation expansion ---
very useful for positioning the mark inside of parentheses, etc.

Special abbreviations are pre-defined for code templates and other
useful items.  To visit the full list of abbreviations, use @kbd{M-x
idlwave-list-abbrevs}.

Template abbreviations:

@multitable @columnfractions .15 .85
@item @code{\pr}
@tab @code{PROCEDURE} template
@item @code{\fu}
@tab @code{FUNCTION} template
@item @code{\c}
@tab @code{CASE} statement template
@item @code{\f}
@tab @code{FOR} loop template
@item @code{\r}
@tab @code{REPEAT} loop template
@item @code{\w}
@tab @code{WHILE} loop template
@item @code{\i}
@tab @code{IF} statement template
@item @code{\elif}
@tab @code{IF-ELSE} statement template
@end multitable

String abbreviations:

@multitable @columnfractions .15 .85
@item @code{\ap}
@tab @code{arg_present()}
@item @code{\b}
@tab @code{begin}
@item @code{\cb}
@tab @code{byte()}
@item @code{\cc}
@tab @code{complex()}
@item @code{\cd}
@tab @code{double()}
@item @code{\cf}
@tab @code{float()}
@item @code{\cl}
@tab @code{long()}
@item @code{\co}
@tab @code{common}
@item @code{\cs}
@tab @code{string()}
@item @code{\cx}
@tab @code{fix()}
@item @code{\e}
@tab @code{else}
@item @code{\ec}
@tab @code{endcase}
@item @code{\ee}
@tab @code{endelse}
@item @code{\ef}
@tab @code{endfor}
@item @code{\ei}
@tab @code{endif else if}
@item @code{\el}
@tab @code{endif else}
@item @code{\en}
@tab @code{endif}
@item @code{\er}
@tab @code{endrep}
@item @code{\es}
@tab @code{endswitch}
@item @code{\ew}
@tab @code{endwhile}
@item @code{\g}
@tab @code{goto,}
@item @code{\h}
@tab @code{help,}
@item @code{\ik}
@tab @code{if keyword_set() then}
@item @code{\iap}
@tab @code{if arg_present() then}
@item @code{\ine}
@tab @code{if n_elements() eq 0 then}
@item @code{\inn}
@tab @code{if n_elements() ne 0 then}
@item @code{\k}
@tab @code{keyword_set()}
@item @code{\n}
@tab @code{n_elements()}
@item @code{\np}
@tab @code{n_params()}
@item @code{\oi}
@tab @code{on_ioerror,}
@item @code{\or}
@tab @code{openr,}
@item @code{\ou}
@tab @code{openu,}
@item @code{\ow}
@tab @code{openw,}
@item @code{\p}
@tab @code{print,}
@item @code{\pt}
@tab @code{plot,}
@item @code{\re}
@tab @code{read,}
@item @code{\rf}
@tab @code{readf,}
@item @code{\rt}
@tab @code{return}
@item @code{\ru}
@tab @code{readu,}
@item @code{\s}
@tab @code{size()}
@item @code{\sc}
@tab @code{strcompress()}
@item @code{\sl}
@tab @code{strlowcase()}
@item @code{\sm}
@tab @code{strmid()}
@item @code{\sn}
@tab @code{strlen()}
@item @code{\sp}
@tab @code{strpos()}
@item @code{\sr}
@tab @code{strtrim()}
@item @code{\st}
@tab @code{strput()}
@item @code{\su}
@tab @code{strupcase()}
@item @code{\t}
@tab @code{then}
@item @code{\u}
@tab @code{until}
@item @code{\wc}
@tab @code{widget_control,}
@item @code{\wi}
@tab @code{widget_info()}
@item @code{\wu}
@tab @code{writeu,}
@end multitable

@noindent You can easily add your own abbreviations or override existing
abbrevs with @code{define-abbrev} in your mode hook, using the
convenience function @code{idlwave-define-abbrev}:

@lisp
(add-hook 'idlwave-mode-hook
          (lambda ()
            (idlwave-define-abbrev "wb" "widget_base()"
                     (idlwave-keyword-abbrev 1))
            (idlwave-define-abbrev "ine" "IF N_Elements() EQ 0 THEN"
                     (idlwave-keyword-abbrev 11))))
@end lisp

Notice how the abbreviation (here @emph{wb}) and its expansion
(@emph{widget_base()}) are given as arguments, and the single argument to
@code{idlwave-keyword-abbrev} (here @emph{1}) specifies how far back to
move the point upon expansion (in this example, to put it between the
parentheses).

The abbreviations are expanded in upper or lower case, depending upon
the variables @code{idlwave-abbrev-change-case} and, for reserved word
templates, @code{idlwave-reserved-word-upcase} (@pxref{Case Changes}).

@defopt idlwave-abbrev-start-char (@code{"\"})
A single character string used to start abbreviations in abbrev mode.
Beware of common characters which might naturally occur in sequence with
abbreviation strings.
@end defopt

@defopt idlwave-abbrev-move (@code{t})
Non-@code{nil} means the abbrev hook can move point, e.g. to end up
between the parentheses of a function call.
@end defopt

@node Actions, Doc Header, Abbreviations, The IDLWAVE Major Mode
@section Actions
@cindex Actions
@cindex Coding standards, enforcing

@emph{Actions} are special formatting commands which are executed
automatically while you write code in order to check the structure of
the program or to enforce coding standards.  Most actions which have
been implemented in IDLWAVE are turned off by default, assuming that the
average user wants her code the way she writes it.  But if you are a
lazy typist and want your code to adhere to certain standards, actions
can be helpful.

Actions can be applied in three ways:

@itemize @bullet
@item
Some actions are applied directly while typing.  For example, pressing
@samp{=} can run a check to make sure that this operator is surrounded
by spaces and insert these spaces if necessary.  Pressing @key{SPC}
after a reserved word can call a command to change the word to upper
case.
@item
When a line is re-indented with @key{TAB}, actions can be applied to the
entire line.  To enable this, the variable @code{idlwave-do-actions}
must be non-@code{nil}.
@item
@cindex Foreign code, adapting
@cindex Actions, applied to foreign code
Actions can also be applied to a larger piece of code, e.g. to convert
foreign code to your own style.  To do this, mark the relevant part of
the code and execute @kbd{M-x expand-region-abbrevs}.  Useful marking
commands are @kbd{C-x h} (the entire file) or @kbd{C-M-h} (the current
subprogram). @xref{Code Indentation}, for information how to adjust the
indentation of the code.
@end itemize

@defopt idlwave-do-actions (@code{nil})
Non-@code{nil} means performs actions when indenting.
@end defopt

@menu
* Block Boundary Check::        Is the END statement correct?
* Padding Operators::           Enforcing space around `=' etc
* Case Changes::                Enforcing upper case keywords
@end menu

@node Block Boundary Check, Padding Operators, Actions, Actions
@subsection Block Boundary Check
@cindex Block boundary check
@cindex @code{END} type checking
@cindex @code{END}, automatic insertion
@cindex @code{END}, expanding
@cindex Block, closing
@cindex Closing a block

Whenever you type an @code{END} statement, IDLWAVE finds the
corresponding start of the block and the cursor blinks back to that
location for a second.  If you have typed a specific @code{END}, like
@code{ENDIF} or @code{ENDCASE}, you get a warning if that terminator
does not match the type of block it terminates.

Set the variable @code{idlwave-expand-generic-end} in order to have all
generic @code{END} statements automatically expanded to the appropriate
type.  You can also type @kbd{C-c ]} to close the current block by
inserting the appropriate @code{END} statement.

@defopt idlwave-show-block (@code{t})
Non-@code{nil} means point blinks to block beginning for
@code{idlwave-show-begin}.
@end defopt

@defopt idlwave-expand-generic-end (@code{t})
Non-@code{nil} means expand generic END to ENDIF/ENDELSE/ENDWHILE etc.
@end defopt

@defopt idlwave-reindent-end (@code{t})
Non-@code{nil} means re-indent line after END was typed.
@end defopt

@node Padding Operators, Case Changes, Block Boundary Check, Actions
@subsection Padding Operators
@cindex Padding operators with spaces
@cindex Operators, padding with spaces
@cindex Space, around operators

Some operators can be automatically surrounded by spaces.  This can
happen when the operator is typed, or later when the line is indented.
IDLWAVE can pad the operators @samp{&}, @samp{<}, @samp{>}, @samp{,},
@samp{=}, and @samp{->}, but this feature is turned off by default.  If
you want to turn it on, customize the variables
@code{idlwave-surround-by-blank} and @code{idlwave-do-actions}.  You can
also define similar actions for other operators by using the function
@code{idlwave-action-and-binding} in the mode hook.  For example, to
enforce space padding of the @samp{+} and @samp{*} operators, try this
in @file{.emacs}

@lisp
(add-hook 'idlwave-mode-hook
  (lambda ()
     (setq idlwave-surround-by-blank t)  ; Turn this type of actions on
     (idlwave-action-and-binding "*" '(idlwave-surround 1 1))
     (idlwave-action-and-binding "+" '(idlwave-surround 1 1))))
@end lisp

@defopt idlwave-surround-by-blank (@code{nil})
Non-@code{nil} means enable @code{idlwave-surround}.  If non-@code{nil},
@samp{=}, @samp{<}, @samp{>}, @samp{&}, @samp{,}, @samp{->} are
surrounded with spaces by @code{idlwave-surround}.
@end defopt

@defopt idlwave-pad-keyword (@code{t})
Non-@code{nil} means pad @samp{=} for keywords like assignments.
@end defopt

@node Case Changes,  , Padding Operators, Actions
@subsection Case Changes
@cindex Case changes
@cindex Upcase, enforcing for reserved words
@cindex Downcase, enforcing for reserved words

Actions can be used to change the case of reserved words or expanded
abbreviations by customizing the variables
@code{idlwave-abbrev-change-case} and
@code{idlwave-reserved-word-upcase}.  If you want to change the case of
additional words automatically, put something like the following into
your @file{.emacs} file:

@lisp
(add-hook 'idlwave-mode-hook
  (lambda ()
     ;;  Capitalize system vars
     (idlwave-action-and-binding idlwave-sysvar '(capitalize-word 1) t)
     ;;  Capitalize procedure name
     (idlwave-action-and-binding "\\<\\(pro\\|function\\)\\>[ \t]*\\<"
                                 '(capitalize-word 1) t)
     ;;  Capitalize common block name
     (idlwave-action-and-binding "\\<common\\>[ \t]+\\<" 
                                 '(capitalize-word 1) t)))
@end lisp

For more information, see the documentation string for the function
@code{idlwave-action-and-binding}.  For information on controlling the
case of routines, keywords, classes, and methods as they are completed, see
@ref{Completion}.

@defopt idlwave-abbrev-change-case (@code{nil})
Non-@code{nil} means all abbrevs will be forced to either upper or lower
case.  Legal values are @code{nil}, @code{t}, and @code{down}.
@end defopt

@defopt idlwave-reserved-word-upcase (@code{nil})
Non-@code{nil} means reserved words will be made upper case via abbrev
expansion.
@end defopt


@node Doc Header, Motion Commands, Actions, The IDLWAVE Major Mode
@section Documentation Header
@cindex Documentation header
@cindex DocLib header
@cindex Modification timestamp
@cindex Header, for file documentation
@cindex Timestamp, in doc header.
@cindex ChangeLog, in doc header.

@kindex C-c C-h
@kindex C-c C-m
The command @kbd{C-c C-h} inserts a standard routine header into the
buffer, with the usual fields for documentation (a different header can
be specified with @code{idlwave-file-header}).  One of the keywords is
@samp{MODIFICATION HISTORY} under which the changes to a routine can be
recorded.  The command @kbd{C-c C-m} jumps to the @samp{MODIFICATION
HISTORY} of the current routine or file and inserts the user name with a
timestamp.

@defopt idlwave-file-header
The doc-header template or a path to a file containing it.
@end defopt

@defopt idlwave-header-to-beginning-of-file (@code{nil})
Non-@code{nil} means the documentation header will always be at start
of file.
@end defopt

@defopt idlwave-timestamp-hook
The hook function used to update the timestamp of a function.
@end defopt

@defopt idlwave-doc-modifications-keyword
The modifications keyword to use with the log documentation commands.
@end defopt

@defopt idlwave-doclib-start
Regexp matching the start of a document library header.
@end defopt

@defopt idlwave-doclib-end
Regexp matching the start of a document library header.
@end defopt

@node Motion Commands, Misc Options, Doc Header, The IDLWAVE Major Mode
@section Motion Commands
@cindex Motion commands
@cindex Program structure, moving through
@cindex Code structure, moving through
@cindex @file{Func-menu}, XEmacs package
@cindex @file{Imenu}, Emacs package
@cindex Function definitions, jumping to
@cindex Procedure definitions, jumping to

IDLWAVE supports both @file{Imenu} and @file{Func-menu}, two packages
which make it easy to jump to the definitions of functions and
procedures in the current file with a pop-up selection.  To bind
@file{Imenu} to a mouse-press, use in your @file{.emacs}:

@lisp
(define-key global-map [S-down-mouse-3] 'imenu)
@end lisp

@cindex @file{Speedbar}, Emacs package

In addition, @file{Speedbar} support allows convenient navigation of a
source tree of IDL routine files, quickly stepping to routine
definitions.  See @code{Tools->Display Speedbar}.

Several commands allow you to move quickly through the structure of an
IDL program:

@multitable @columnfractions .15 .85
@item @kbd{C-M-a}
@tab Beginning of subprogram
@item @kbd{C-M-e}
@tab End of subprogram
@item @kbd{C-c @{}
@tab Beginning of block (stay inside the block)
@item @kbd{C-c @}}
@tab End of block (stay inside the block)
@item @kbd{C-M-n}
@tab Forward block (on same level)
@item @kbd{C-M-p}
@tab Backward block (on same level)
@item @kbd{C-M-d}
@tab Down block (enters a block)
@item @kbd{C-M-u}
@tab Backward up block (leaves a block)
@item @kbd{C-c C-n}
@tab Next Statement
@end multitable


@node Misc Options,  , Motion Commands, The IDLWAVE Major Mode
@section Miscellaneous Options
@cindex Hooks

@defopt idlwave-help-application
The external application providing reference help for programming.
@end defopt

@defopt idlwave-startup-message (@code{t})
Non-@code{nil} means display a startup message when @code{idlwave-mode}'
is first called.
@end defopt

@defopt idlwave-mode-hook
Normal hook.  Executed when a buffer is put into @code{idlwave-mode}.
@end defopt

@defopt idlwave-load-hook
Normal hook.  Executed when @file{idlwave.el} is loaded.
@end defopt



@node The IDLWAVE Shell, Installation, The IDLWAVE Major Mode, Top
@chapter The IDLWAVE Shell
@cindex IDLWAVE shell
@cindex Major mode, @code{idlwave-shell-mode}
@cindex IDL, as Emacs subprocess
@cindex Subprocess of Emacs, IDL
@cindex Comint, Emacs package
@cindex Windows
@cindex MacOS

The IDLWAVE shell is an Emacs major mode which permits running the IDL
program as an inferior process of Emacs, and works closely with the
IDLWAVE major mode in buffers.  It can be used to work with IDL
interactively, to compile and run IDL programs in Emacs buffers and to
debug these programs.  The IDLWAVE shell is built upon @file{comint}, an
Emacs packages which handles the communication with the IDL program.
Unfortunately IDL for Windows and MacOS do not have command-prompt
versions and thus do not allow the interaction with
Emacs@footnote{Please inform the maintainer if you come up with a way to
make the IDLWAVE shell work on these systems.} --- so the IDLWAVE shell
currently only works under Unix.

@menu
* Starting the Shell::          How to launch IDL as a subprocess
* Using the Shell::             Interactively working with the Shell
* Commands Sent to the Shell::  
* Debugging IDL Programs::      
* Examining Variables::         
* Custom Expression Examination::  
@end menu

@node Starting the Shell, Using the Shell, The IDLWAVE Shell, The IDLWAVE Shell
@section Starting the Shell
@cindex Starting the shell
@cindex Shell, starting
@cindex Dedicated frame, for shell buffer
@cindex Frame, for shell buffer
@cindex Subprocess of Emacs, IDL

@kindex C-c C-s
The IDLWAVE shell can be started with the command @kbd{M-x
idlwave-shell}.  In @code{idlwave-mode} the function is bound to
@kbd{C-c C-s}.  It creates a buffer @file{*idl*} which is used to
interact with the shell.  If the shell is already running, @kbd{C-c C-s}
will simple switch to the shell buffer.  The command @kbd{C-c C-l}
(@code{idlwave-shell-recenter-shell-window}) displays the shell window
without selecting it.  The shell can also be started automatically when
another command tries to send a command to it.  To enable auto start,
set the variable @code{idlwave-shell-automatic-start} to @code{t}.

In order to create a separate frame for the IDLWAVE shell buffer, call
@code{idlwave-shell} with a prefix argument: @kbd{C-u C-c C-s} or
@kbd{C-u C-c C-l}.  If you always want a dedicated frame for the shell
window, configure the variable
@code{idlwave-shell-use-dedicated-frame}. 

To launch a quick IDLWAVE shell directly from a shell prompt without an
IDLWAVE buffer (e.g., as a replacement for running inside an xterm),
define an alias with the following content:

@example
emacs -geometry 80x32 -eval "(idlwave-shell 'quick)"
@end example

Replace the @samp{-geometry 80x32} option with @samp{-nw} if you prefer
the Emacs process to run directly inside the terminal window.

@defopt idlwave-shell-explicit-file-name (@file{idl})
This is the command to run IDL.
@end defopt

@defopt idlwave-shell-command-line-options
A list of command line options for calling the IDL program.
@end defopt

@defopt idlwave-shell-prompt-pattern
Regexp to match IDL prompt at beginning of a line.
@end defopt

@defopt idlwave-shell-process-name
Name to be associated with the IDL process.
@end defopt

@defopt idlwave-shell-automatic-start  (@code{nil})
Non-@code{nil} means attempt to invoke idlwave-shell if not already
running.
@end defopt

@defopt idlwave-shell-initial-commands
Initial commands, separated by newlines, to send to IDL.
@end defopt

@defopt idlwave-shell-save-command-history (@code{t})
Non-@code{nil} means preserve command history between sessions.
@end defopt

@defopt idlwave-shell-command-history-file (@file{~/.idlwhist})
The file in which the command history of the idlwave shell is saved.
@end defopt
  
@defopt idlwave-shell-use-dedicated-frame (@code{nil})
Non-@code{nil} means IDLWAVE should use a special frame to display
shell buffer. 
@end defopt

@defopt idlwave-shell-frame-parameters
The frame parameters for a dedicated idlwave-shell frame.
@end defopt

@defopt idlwave-shell-raise-frame (@code{t})
Non-@code{nil} means `idlwave-shell' raises the frame showing the shell
window.
@end defopt

@defopt idlwave-shell-temp-pro-prefix
The prefix for temporary IDL files used when compiling regions.
@end defopt

@cindex Hooks
@defopt idlwave-shell-mode-hook
Hook for customizing @code{idlwave-shell-mode}.
@end defopt

@node Using the Shell, Commands Sent to the Shell, Starting the Shell, The IDLWAVE Shell
@section Using the Shell
@cindex Comint
@cindex Shell, basic commands

The IDLWAVE shell works in the same fashion as other shell modes in
Emacs.  It provides command history, command line editing and job
control.  The @key{UP} and @key{DOWN} arrows cycle through the input
history just like in an X terminal@footnote{This is different from
normal Emacs/Comint behavior, but more like an xterm.  If you prefer the
default comint functionality, check the variable
@code{idlwave-shell-arrows-do-history}.}.  The history is preserved
between emacs and IDL sessions.  Here is a list of commonly used
commands:

@multitable @columnfractions .12 .88
@item @key{UP}, @key{M-p}
@tab Cycle backwards in input history
@item @key{DOWN}, @key{M-n}
@tab Cycle forwards in input history
@item @kbd{M-r}
@tab Previous input matching a regexp
@item @kbd{M-s}
@tab Next input matching a regexp
@item @kbd{return}
@tab Send input or copy line to current prompt
@item @kbd{C-c C-a}
@tab Beginning of line; skip prompt
@item @kbd{C-c C-u}
@tab Kill input to beginning of line
@item @kbd{C-c C-w}
@tab Kill word before cursor
@item @kbd{C-c C-c}
@tab Send ^C
@item @kbd{C-c C-z}
@tab Send ^Z
@item @kbd{C-c C-\}
@tab Send ^\
@item @kbd{C-c C-o}
@tab Delete last batch of process output
@item @kbd{C-c C-r}
@tab Show last batch of process output
@item @kbd{C-c C-l}
@tab List input history
@end multitable

In addition to these standard @file{comint} commands,
@code{idlwave-shell-mode} provides many of the same commands which
simplify writing IDL code available in IDLWAVE buffers.  This includes
abbreviations, online help, and completion.  See @ref{Routine Info} and
@ref{Online Help} and @ref{Completion} for more information on these
commands.

@cindex Completion, in the shell
@cindex Routine info, in the shell
@cindex Online Help, in the shell
@multitable @columnfractions .12 .88
@item @kbd{@key{TAB}}
@tab  Completion of file names (between quotes and after executive
commands @samp{.run} and @samp{.compile}), routine names, class names,
keywords, system variables, system variable tags etc.
(@code{idlwave-shell-complete}).
@item @kbd{M-@key{TAB}}
@tab Same as @key{TAB}
@item @kbd{C-c ?}
@tab Routine Info display (@code{idlwave-routine-info})
@item @kbd{M-?}
@tab IDL online help on routine (@code{idlwave-routine-info-from-idlhelp})
@item @kbd{C-c C-i}
@tab Update routine info from buffers and shell
(@code{idlwave-update-routine-info})
@item @kbd{C-c C-v}
@tab Find the source file of a routine (@code{idlwave-find-module})
@item @kbd{C-c =}
@tab Compile a library routine (@code{idlwave-resolve})
@end multitable

@defopt idlwave-shell-arrows-do-history (@code{t})
Non-@code{nil} means @key{UP} and @key{DOWN} arrows move through command
history like xterm.
@end defopt

@defopt idlwave-shell-comint-settings
Alist of special settings for the comint variables in the IDLWAVE Shell.
@end defopt

@defopt idlwave-shell-file-name-chars
The characters allowed in file names, as a string.  Used for file name
completion.
@end defopt

@defopt idlwave-shell-graphics-window-size
Size of IDL graphics windows popped up by special IDLWAVE command.
@end defopt

@cindex Input mode
@cindex Character input mode (Shell)
@cindex Line input mode (Shell)
@cindex Magic spells, for input mode
@cindex Spells, magic
IDLWAVE works in line input mode: You compose a full command line, using
all the power Emacs gives you to do this.  When you press @key{RET}, the
whole line is sent to IDL.  Sometimes it is necessary to send single
characters (without a newline), for example when an IDL program is
waiting for single character input with the @code{GET_KBRD} function.
You can send a single character to IDL with the command @kbd{C-c C-x}
(@code{idlwave-shell-send-char}).  When you press @kbd{C-c C-y}
(@code{idlwave-shell-char-mode-loop}), IDLWAVE runs a blocking loop
which accepts characters and immediately sends them to IDL.  The loop
can be exited with @kbd{C-g}.  It terminates also automatically when the
current IDL command is finished.  Check the documentation of the two
variables described below for a way to make IDL programs trigger
automatic switches of the input mode.

@defopt idlwave-shell-use-input-mode-magic (@code{nil})
Non-@code{nil} means IDLWAVE should check for input mode spells in
output.
@end defopt

@defopt idlwave-shell-input-mode-spells
The three regular expressions which match the magic spells for input
modes.
@end defopt

@node Commands Sent to the Shell, Debugging IDL Programs, Using the Shell, The IDLWAVE Shell
@section Commands Sent to the Shell
@cindex Commands in shell, showing
@cindex Showing commands in shell

The IDLWAVE buffers and shell interact very closely.  In addition to the
normal commands you enter at the @code{IDL>} prompt, many other special
commands are sent to the shell, sometimes as a direct result of invoking
a key command, menu item, or toolbar button, but also automatically, as
part of the normal flow of information updates between the buffer and
shell.

The commands sent include @code{breakpoint}, @code{.step} and other
debug commands (@pxref{Debugging IDL Programs}), @code{.run} and other
compilation statements (@pxref{Compiling Programs}), examination
commands like @code{print} and @code{help} (@pxref{Examining
Variables}), and other special purpose commands designed to keep
information on the running shell current.

By default, much of this background shell input and output is hidden
from the user, but this is configurable.  The custom variable
@code{idlwave-abbrev-show-commands} allows you to configure which
commands sent to the shell are shown there.  For a related customization
for separating the output of @emph{examine} commands @xref{Examining
Variables}.

@defopt idlwave-shell-show-commands (@code{'(run misc breakpoint)})
A list of command types to echo in the shell when sent.  Possible values
are @code{run} for @code{.run}, @code{.compile} and other run commands,
@code{misc} for lesser used commands like @code{window}, @code{retall},
etc., @code{breakpoint} for breakpoint setting and clearing commands,
and @code{debug} for other debug, stepping, and continue commands.  In
addition, if the variable is set to the single symbol @code{'everything},
all the copious shell input is displayed (which is probably only useful
for debugging purposes).
@end defopt

@node Debugging IDL Programs, Examining Variables, Commands Sent to the Shell, The IDLWAVE Shell
@section Debugging IDL Programs
@cindex Debugging
@cindex Keybindings for debugging
@cindex Toolbar

Programs can be compiled, run, and debugged directly from the source
buffer in Emacs.  IDLWAVE makes compiling and debugging IDL programs
far less cumbersome by providing a full-featured,
key/menu/toolbar-driven interface to commands like @code{breakpoint},
@code{.step}, @code{.run}, etc.

The IDLWAVE shell installs key bindings both in the shell buffer and in
all IDL code buffers of the current Emacs session, so debug commands
work in both places (in the shell, commands operate on the last file
compiled).  On Emacs versions which support this, a debugging toolbar is
also installed.  The display of the toolbar can be toggled with @kbd{C-c
C-d C-t} (@code{idlwave-shell-toggle-toolbar}).

@defopt idlwave-shell-use-toolbar (@code{t})
Non-@code{nil} means use the debugging toolbar in all IDL related
buffers.
@end defopt

@menu
* Debug Key Bindings::          
* Compiling Programs::          
* Breakpoints and Stepping::    
* Walking the Calling Stack::   
@end menu

@node Debug Key Bindings, Compiling Programs, Debugging IDL Programs, Debugging IDL Programs
@subsection Debug Key Bindings
@kindex C-c C-d
@cindex Key bindings

The debugging key bindings are by default on the prefix key @kbd{C-c
C-d}, so for example setting a breakpoint is done with @kbd{C-c C-d
C-b}, and compiling a source file with @kbd{C-c C-d C-c}.  If you find
this too much work, you can easily configure IDLWAVE to use one or more
modifier keys not in use by other commands, in lieu of the prefix
@kbd{C-c C-d} (though these bindings will typically also be available
--- see @code{idlwave-shell-activate-prefix-keybindings}).  For example,
if you write in @file{.emacs}:

@lisp
(setq idlwave-shell-debug-modifiers '(control shift))
@end lisp

@noindent a breakpoint can be set by pressing @kbd{b} while holding down
@kbd{shift} and @kbd{control} keys, i.e. @kbd{C-S-b}.  Compiling a
source file will be on @kbd{C-S-c}, deleting a breakpoint @kbd{C-S-d},
etc.  In the remainder of this chapter we will assume that the @kbd{C-c
C-d} bindings are active, but each of these bindings will have an
equivalent single-keypress shortcut if modifiers are given in the
@code{idlwave-shell-debug-modifiers} variable (see @pxref{Lesson II --
Customization}).

@defopt idlwave-shell-prefix-key (@kbd{C-c C-d})
The prefix key for the debugging map
@code{idlwave-shell-mode-prefix-map}.
@end defopt

@defopt idlwave-shell-activate-prefix-keybindings (@code{t})
Non-@code{nil} means debug commands will be bound to the prefix
key, like @kbd{C-c C-d C-b}.
@end defopt

@defopt idlwave-shell-debug-modifiers (@code{nil})
List of modifier keys to use for additional binding of debugging
commands in the shell and source buffers.  Can be one or more of
@code{control}, @code{meta}, @code{super}, @code{hyper}, @code{alt}, and
@code{shift}.
@end defopt

@node Compiling Programs, Breakpoints and Stepping, Debug Key Bindings, Debugging IDL Programs
@subsection Compiling Programs
@cindex Compiling programs
@cindex Programs, compiling
@cindex Default command line, executing
@cindex Executing a default command line

@kindex C-c C-d C-c
In order to compile the current buffer under the IDLWAVE shell, press
@kbd{C-c C-d C-c} (@code{idlwave-save-and-run}).  This first saves the
current buffer and then sends the command @samp{.run path/to/file} to the 
shell.  You can also execute @kbd{C-c C-d C-c} from the shell buffer, in 
which case the most recently compiled buffer will be saved and
re-compiled.

When developing or debugging a program, it is often necessary to execute 
the same command line many times.  A convenient way to do this is
@kbd{C-c C-d C-y} (@code{idlwave-shell-execute-default-command-line}).
This command first resets IDL from a state of interrupted execution by
closing all files and returning to the main interpreter level.  Then a
default command line is send to the shell.  To edit the default command
line, call @code{idlwave-shell-execute-default-command-line} with a
prefix argument: @kbd{C-u C-c C-d C-y}.

@defopt idlwave-shell-mark-stop-line (@code{t})
Non-@code{nil} means mark the source code line where IDL is currently
stopped.  The value specifies the preferred method.  Legal values are
@code{nil}, @code{t}, @code{arrow}, and @code{face}.
@end defopt

@defopt idlwave-shell-overlay-arrow (@code{">"})
The overlay arrow to display at source lines where execution halts, if
configured in @code{idlwave-shell-mark-stop-line}.
@end defopt

@defopt idlwave-shell-stop-line-face
The face which highlights the source line where IDL is stopped, if
configured in @code{idlwave-shell-mark-stop-line}.
@end defopt

@node Breakpoints and Stepping, Walking the Calling Stack, Compiling Programs, Debugging IDL Programs
@subsection Breakpoints and Stepping
@cindex Breakpoints
@cindex Stepping
@cindex Execution, controlled

@kindex C-c C-d C-b
@kindex C-c C-d C-b
You can set breakpoints and step through a program with IDLWAVE.
Setting a breakpoint in the current line of the source buffer is done
with @kbd{C-c C-d C-b} (@code{idlwave-shell-break-here}).  With a prefix
arg of 1 (i.e. @kbd{C-1 C-c C-d C-b}), the breakpoint gets a
@code{/ONCE} keyword, meaning that it will be deleted after first use.
With a numeric prefix greater than one (e.g. @kbd{C-4 C-c C-d C-b}), the
breakpoint will only be active the @code{nth} time it is hit.  With a
single non-numeric prefix (i.e. @kbd{C-u C-c C-d C-b}), prompt for a
condition --- an IDL expression to be evaulated and trigger the
breakpoint only if true.  To clear the breakpoint in the current line,
use @kbd{C-c C-d C-d} (@code{idlwave-clear-current-bp}).  When executed
from the shell window, the breakpoint where IDL is currently stopped
will be deleted.  To clear all breakpoints, use @kbd{C-c C-d C-a}
(@code{idlwave-clear-all-bp}).  Breakpoint lines are highlighted in the
source code.  Note that IDL places breakpoints as close as possible on
or after the line you specify.  IDLWAVE queries the shell for the actual
breakpoint location which was set, so the exact line you specify may not
be marked.

Once the program has stopped somewhere, you can step through it.  The
most important stepping commands are @kbd{C-c C-d C-s} to execute one
line of IDL code ("step into"); @kbd{C-c C-d C-n} to step a single line,
treating procedure and function calls as a single step ("step over");
@kbd{C-c C-d C-h} to continue execution to the line at the cursor and
@kbd{C-c C-d C-r} to continue execution.  @xref{Commands Sent to the
Shell}, for information on displaying or hiding the breakpoint and
stepping commands the shell receives.  Here is a summary of the
breakpoint and stepping commands:

@multitable @columnfractions .23 .77
@item @kbd{C-c C-d C-b}
@tab Set breakpoint (@code{idlwave-shell-break-here})
@item @kbd{C-c C-d C-i}
@tab Set breakpoint in function named here (@code{idlwave-shell-break-in})
@item @kbd{C-c C-d C-d}
@tab Clear current breakpoint (@code{idlwave-shell-clear-current-bp})
@item @kbd{C-c C-d C-a}
@tab Clear all breakpoints (@code{idlwave-shell-clear-all-bp})
@item @kbd{C-c C-d C-s}
@tab Step, into function calls (@code{idlwave-shell-step})
@item @kbd{C-c C-d C-n}
@tab Step, over function calls (@code{idlwave-shell-stepover})
@item @kbd{C-c C-d C-k}
@tab Skip one statement (@code{idlwave-shell-skip})
@item @kbd{C-c C-d C-u}
@tab Continue to end of block (@code{idlwave-shell-up})
@item @kbd{C-c C-d C-m}
@tab Continue to end of function (@code{idlwave-shell-return})
@item @kbd{C-c C-d C-o}
@tab Continue past end of function (@code{idlwave-shell-out})
@item @kbd{C-c C-d C-h}
@tab Continue to line at cursor position (@code{idlwave-shell-to-here})
@item @kbd{C-c C-d C-r}
@tab Continue execution to next breakpoint (@code{idlwave-shell-cont})
@item @kbd{C-c C-d C-up}
@tab Show higher level in calling stack (@code{idlwave-shell-stack-up})
@item @kbd{C-c C-d C-down}
@tab Show lower level in calling stack (@code{idlwave-shell-stack-down})
@end multitable

@defopt idlwave-shell-mark-breakpoints (@code{t})
Non-@code{nil} means mark breakpoints in the source file buffers.  The
value indicates the preferred method.  Legal values are @code{nil},
@code{t}, @code{face}, and @code{glyph}.
@end defopt

@defopt idlwave-shell-breakpoint-face
The face for breakpoint lines in the source code if
@code{idlwave-shell-mark-breakpoints} has the value @code{face}.
@end defopt

@node Walking the Calling Stack,  , Breakpoints and Stepping, Debugging IDL Programs
@subsection Walking the Calling Stack
@cindex Calling stack, walking

While debugging a program, it can be very useful to check the context in
which the current routine was called, for instance to help understand
the value of the arguments passed.  To do so conveniently you need to
examine the calling stack.  If execution is stopped somewhere deep in a
program, you can use the commands @kbd{C-c C-d C-@key{UP}}
(@code{idlwave-shell-stack-up}) and @kbd{C-c C-d C-@key{DOWN}}
(@code{idlwave-shell-stack-down}), or the corresponding toolbar buttons,
to move up or down through the calling stack.  The mode line of the
shell window will indicate the position within the stack with a label
like @samp{[-3:MYPRO]}.  The line of IDL code at that stack position
will be highlighted.  If you continue execution, IDLWAVE will
automatically return to the current level. @xref{Examining Variables},
for information how to examine the value of variables and expressions on
higher calling stack levels.

@ifhtml
<A NAME="EXAMINE"></A>
@end ifhtml
@node Examining Variables, Custom Expression Examination, Debugging IDL Programs, The IDLWAVE Shell
@section Examining Variables
@cindex @code{PRINT} expressions
@cindex @code{HELP}, on expressions
@cindex Expressions, printing
@cindex Expressions, help
@cindex Printing expressions
@cindex Mouse binding to print expressions

@kindex C-c C-d C-p
Do you find yourself repeatedly typing, e.g. @code{print,n_elements(x)},
and similar statements to remind yourself of the
type/size/structure/value/etc. of variables and expressions in your code
or at the command line?  IDLWAVE has a suite of special commands to
automate these types of variables or expression examinations.  They work
by sending statements to the shell formatted to include the indicated
expression.

These examination commands can be used in the shell or buffer at any
time (as long as the shell is running), and are very useful when
execution is stopped in a buffer due to a triggered breakpoint or error,
or while composing a long command in the IDLWAVE shell.  In the latter
case, the command is sent to the shell and its output is visible, but
point remains unmoved in the command being composed --- you can inspect
the constituents of a command you're building without interrupting the
process of building it!  You can even print arbitrary expressions from
older input or output further up in the shell window --- any expression,
variable, number, or function you see can be examined.

If the variable @code{idlwave-shell-separate-examine-output} is
non-@code{nil} (the default), all examine output will be sent to a
special @file{*Examine*} buffer, rather than the shell.  The output of
prior examine commands is saved.  In this buffer @key{c} clears the
contents, and @key{q} hides the buffer.

The two most basic examine commands are bound to @kbd{C-c C-d C-p}, to
print the expression at point, and @kbd{C-c C-d ?}, to invoke help on
this expression.  The expression at point is either an array expression
or a function call, or the contents of a pair of parentheses.  The
selected expression is highlighted, and simultaneously the resulting
output is highlighted in the shell.  Calling the above commands with a
prefix argument will prompt for an expression instead of using the one
at point.  Two prefix arguments (@kbd{C-u C-u C-c C-d C-p}) will use the
current region as expression.

For added speed and convenience, there are mouse bindings which allow
you to click on expressions and examine their values.  Use
@kbd{S-Mouse-2} to print an expression and @kbd{C-M-Mouse-2} to invoke
help (i.e. you need to hold down @key{META} and @key{CONTROL} while
clicking with the middle mouse button).  If you simply click, the
nearest expression will be selected in the same manner as described
above.  You can also @emph{drag} the mouse in order to highlight exactly
a specific expression or sub-expression to be examined.  For custom
expression examination, and the customizable pop-up examine selection,
@xref{Custom Expression Examination}.

@cindex Printing expressions, on calling stack
@cindex Restrictions for expression printing
The same variable inspection commands work both in the IDL Shell and
IDLWAVE buffers, and even for variables at higher levels of the calling
stack.  For instance, if you're stopped at a breakpoint in a routine,
you can examine the values of variables and expressions inside its
calling routine, and so on, all the way up through the calling stack.
Simply step up the stack, and print variables as you see them
(@pxref{Walking the Calling Stack}, for information on stepping back
through the calling stack).  The following restrictions apply for all
levels except the current:

@itemize @bullet
@item
Array expressions must use the @samp{[ ]} index delimiters.  Identifiers
with a @samp{( )} will be interpreted as function calls.
@item
@cindex ROUTINE_NAMES, IDL procedure
N.B.: printing values of expressions on higher levels of the calling
stack uses the @emph{unsupported} IDL routine @code{ROUTINE_NAMES},
which may or may not be available in future versions of IDL.
@end itemize

@defopt idlwave-shell-expression-face
The face for @code{idlwave-shell-expression-overlay}.
Allows you to choose the font, color and other properties for
the expression printed by IDL.
@end defopt

@defopt idlwave-shell-output-face
The face for @code{idlwave-shell-output-overlay}.  
Allows to choose the font, color and other properties for the most
recent output of IDL when examining an expression."
@end defopt

@defopt idlwave-shell-separate-examine-output (@code{t})
If non-@code{nil}, re-direct the output of examine commands to a special
@file{*Examine*} buffer, instead of in the shell itself. 
@end defopt

@node Custom Expression Examination,  , Examining Variables, The IDLWAVE Shell
@section Custom Expression Examination
@cindex Expressions, custom examination
@cindex Custom expression examination

The variety of possible variable and expression examination commands is
endless (just look, for instance, at the keyword list to
@code{widget_info()}).  Rather than attempt to include them all, IDLWAVE
provides two easy methods to customize your own commands, with a special
mouse examine command, and two macros for generating your own examine
bindings.

The most powerful and flexible mouse examine command is available on
@kbd{C-S-Mouse-2}.  Just as for all the other mouse examine commands, it
permits click or drag expression selection, but instead of sending
hard-coded commands to the shell, it pops-up a customizable selection
list of examine functions to choose among, configured with the
@code{idlwave-shell-examine-alist} variable.  This variable is a list of
key-value pairs (an @emph{alist} in Emacs parlance), where the keys name
the command, and the values are the command strings, in which the text
@code{___} (three underscores) will be replaced by the selected
expression before being sent to the shell.  An example might be key
@code{Structure Help} with value @code{help,___,/STRUCTURE}.
@code{idlwave-shell-examine-alist} comes by default with a large list of
examine commands, but can be easily customized to add more.

In addition to the pop-up mouse command, you can easily create your own
customized bindings to inspect expressions using the two convenience
macros @code{idlwave-shell-inspect} and
@code{idlwave-shell-mouse-inspect}.  These create keyboard or
mouse-based custom inspections of variables, sharing all the same
properties of the built-in examine commands.  Both functions take a
single string argument sharing the syntax of the
@code{idlwave-shell-examine-alist} values, e.g.:

@lisp
(add-hook 'idlwave-shell-mode-hook
          (lambda ()
            (idlwave-shell-define-key-both [s-down-mouse-2] 
                                 (idlwave-shell-mouse-examine 
                                  "print, size(___,/DIMENSIONS)"))
            (idlwave-shell-define-key-both [f9] (idlwave-shell-examine
                                       "print, size(___,/DIMENSIONS)"))
            (idlwave-shell-define-key-both [f10] (idlwave-shell-examine 
                                        "print,size(___,/TNAME)"))
            (idlwave-shell-define-key-both [f11] (idlwave-shell-examine
                                        "help,___,/STRUCTURE"))))
@end lisp                                        
            
@noindent Now pressing @key{f9}, or middle-mouse dragging with the
@key{SUPER} key depressed, will print the dimensions of the nearby or
highlighted expression.  Pressing @key{f10} will give the type string,
and @key{f11} will show the contents of a nearby structure.  As you can
see, the possibilities are only marginally finite.

@defopt idlwave-shell-examine-alist
An alist of examine commands in which the keys name the command and are
displayed in the selection pop-up, and the values are custom IDL examine
command strings to send, after all instances of @code{___} are replaced
by the indicated expression.
@end defopt


@node Installation, Acknowledgements, The IDLWAVE Shell, Top
@chapter Installation
@cindex Installation

@menu
* Installing IDLWAVE::          How to install the distribution
* Installing Online Help::      Where to get the additional files needed
* Upgrading from idl.el::       Necessary configuration changes
@end menu

@node Installing IDLWAVE, Installing Online Help, Installation, Installation
@section Installing IDLWAVE

@cindex FTP site
@cindex URL, homepage for IDLWAVE
@cindex Homepage for IDLWAVE
@cindex IDLWAVE, homepage
@cindex XEmacs package IDLWAVE
@cindex Emacs, distributed with IDLWAVE
@cindex Copyright, of IDL manual
IDLWAVE is part of Emacs 21.1 and later.  It is also an XEmacs package
and can be installed from
@uref{ftp://ftp.xemacs.org/pub/xemacs/packages/,the XEmacs ftp site}
with the normal package management system on XEmacs 21.  These
pre-installed versions should work out-of-the-box.  However, the files
required for online help are not distributed with XEmacs/Emacs and have
to be installed separately@footnote{Due to copyright reasons, the ASCII
version of the IDL manual cannot be distributed under the GPL.}
(@pxref{Installing Online Help}).

You can also download IDLWAVE and install it yourself from
@uref{@value{IDLWAVE-HOMEPAGE}, the maintainers webpage}.  Follow the
instructions in the INSTALL file.

@node Installing Online Help, Upgrading from idl.el, Installing IDLWAVE, Installation
@section Installing Online Help
@cindex Installing online help
@cindex Online Help, Installation

If you want to use the online help display, two additional files (an
ASCII version of the IDL documentation and a topics/code file) must be
installed.  These files can also be downloaded from
@uref{@value{IDLWAVE-HOMEPAGE}, the maintainers webpage}.  You need to
place the files somewhere on your system and tell IDLWAVE where they are
with

@lisp
(setq idlwave-help-directory "/path/to/help/files/")
@end lisp

@node Upgrading from idl.el,  , Installing Online Help, Installation
@section Upgrading from the old @b{@file{idl.el}} file
@cindex Upgrading from old @b{@file{idl.el}}
@cindex Renaming old variables
@cindex Old variables, renaming
@kindex M-@key{TAB}

If you have been using the old @file{idl.el} and @file{idl-shell.el}
files and would like to use IDLWAVE, you need to update your
customization in @file{.emacs}.

@enumerate
@item
Change all variable and function prefixes from @samp{idl-} to @samp{idlwave-}.
@item
Remove the now invalid @code{autoload} and @code{auto-mode-alist} forms
pointing to the @file{idl.el} and @file{idl-shell.el} files.  Install
the new autoload forms.
@item
If you have been using the hook function recommended in earlier versions
to get a separate frame for the IDL shell, remove that command from your
@code{idlwave-shell-mode-hook}.  Instead, set the variable
@code{idlwave-shell-use-dedicated-frame} with
@lisp
(setq idlwave-shell-use-dedicated-frame t)
@end lisp
@item 
The key sequence @kbd{M-@key{TAB}} no longer inserts a TAB character.
Like in many other Emacs modes, @kbd{M-@key{TAB}} now does
completion.  Inserting a TAB has therefore been moved to
@kbd{C-@key{TAB}}.  On a character based terminal you can also use
@kbd{C-c @key{SPC}}.
@end enumerate

@node Acknowledgements, Sources of Routine Info, Installation, Top
@chapter Acknowledgements
@cindex Acknowledgements
@cindex Maintainer, of IDLWAVE
@cindex Authors, of IDLWAVE
@cindex Contributors, to IDLWAVE
@cindex Email address, of Maintainer
@cindex Thanks

@noindent
The main contributors to the IDLWAVE package have been:

@itemize @minus
@item
@uref{mailto:chase@@att.com, @b{Chris Chase}}, the original author.
Chris wrote @file{idl.el} and @file{idl-shell.el} and maintained them
for several years.

@item
@uref{mailto:dominik@@astro.uva.nl, @b{Carsten Dominik}} was in charge
of the package from version 3.0, during which time he overhauled almost
everything, modernized IDLWAVE with many new features, and developed the
manual.

@item 
@uref{mailto:jdsmith@@as.arizona.edu, @b{J.D. Smith}}, the current
maintainer, as of version 4.10, helped shape object method completion
and most new features introduced in versions 4.x.
@end itemize

@noindent
The following people have also contributed to the development of IDLWAVE
with patches, ideas, bug reports and suggestions.

@itemize @minus
@item
Ulrik Dickow <dickow@@nbi.dk>
@item
Eric E. Dors <edors@@lanl.gov>
@item
Stein Vidar H. Haugan <s.v.h.haugan@@astro.uio.no>
@item
David Huenemoerder <dph@@space.mit.edu>
@item
Kevin Ivory <Kevin.Ivory@@linmpi.mpg.de>
@item
Dick Jackson <dick@@d-jackson.com>
@item
Xuyong Liu <liu@@stsci.edu>
@item
Simon Marshall <Simon.Marshall@@esrin.esa.it>
@item
Craig Markwardt <craigm@@cow.physics.wisc.edu>
@item
Laurent Mugnier <mugnier@@onera.fr>
@item
Lubos Pochman <lubos@@rsinc.com>
@item
Bob Portmann <portmann@@al.noaa.gov>
@item
Patrick M. Ryan <pat@@jaameri.gsfc.nasa.gov>
@item
Marty Ryba <ryba@@ll.mit.edu>
@item
Phil Williams <williams@@irc.chmcc.org>
@item
Phil Sterne <sterne@@dublin.llnl.gov>
@end itemize

@noindent
Thanks to everyone!

@node Sources of Routine Info, Configuration Examples, Acknowledgements, Top
@appendix Sources of Routine Info

@cindex Sources of routine information
In @ref{Routine Info} and @ref{Completion} we showed how IDLWAVE
displays the calling sequence and keywords of routines, and completes
routine names and keywords.  For these features to work, IDLWAVE must
know about the accessible routines.

@menu
* Routine Definitions::         Where IDL Routines are defined.
* Routine Information Sources::  So how does IDLWAVE know about...
* Library Catalog::             Scanning the Libraries for Routine Info
* Load-Path Shadows::           Routines defined in several places
* Documentation Scan::          Scanning the IDL Manuals
@end menu

@node Routine Definitions, Routine Information Sources, Sources of Routine Info, Sources of Routine Info
@appendixsec Routine Definitions
@cindex Routine definitions
@cindex IDL variable @code{!PATH}
@cindex @code{!PATH}, IDL variable
@cindex @code{CALL_EXTERNAL}, IDL routine
@cindex @code{LINKIMAGE}, IDL routine
@cindex External routines

@noindent Routines which can be used in an IDL program can be defined in
several places:

@enumerate
@item 
@emph{Builtin routines} are defined inside IDL itself.  The source
code of such routines is not available.
@item
Routines which are @emph{part of the current program}, are defined in a
file explicitly compiled by the user.  This file may or may not be
located on the IDL search path.
@item 
@emph{Library routines} are defined in files located on IDL's search
path, and will not need to be manually compiled.  When a library routine
is called for the first time, IDL will find the source file and compile
it dynamically.  A special sub-category of library routines are the
@emph{system routines} distributed with IDL, and usually available in
the @file{lib} subdirectory of the IDL distribution.
@item
External routines written in other languages (like Fortran or C) can be
called with @code{CALL_EXTERNAL}, linked into IDL via @code{LINKIMAGE},
or included as dynamically loaded modules (DLMs).  Currently IDLWAVE
cannot provide routine info and completion for such external routines.
@end enumerate

@node Routine Information Sources, Library Catalog, Routine Definitions, Sources of Routine Info
@appendixsec Routine Information Sources
@cindex Routine info sources
@cindex Builtin list of routines
@cindex Updating routine info
@cindex Scanning buffers for routine info
@cindex Buffers, scanning for routine info
@cindex Shell, querying for routine info

@noindent To maintain the most comprehensive information about all IDL
routines on a system, IDLWAVE collects data from many sources:

@enumerate

@item
It has a @emph{builtin list} with the properties of the builtin IDL
routines.  IDLWAVE @value{VERSION} is distributed with a list of
@value{NSYSROUTINES} routines and @value{NSYSKEYWORDS} keywords,
reflecting IDL version @value{IDLVERSION}.  This list has been created
by scanning the IDL manuals and is stored in the file
@file{idlw-rinfo.el}.  @xref{Documentation Scan}, for information on how
to regenerate this file for new versions of IDL.

@item 
It @emph{scans} all @emph{buffers} of the current Emacs session for
routine definitions.  This is done automatically when routine
information or completion is first requested by the user.  Each new
buffer and each buffer which is saved after making changes is also
scanned. The command @kbd{C-c C-i} (@code{idlwave-update-routine-info})
can be used at any time to rescan all buffers.

@item
If you have an IDLWAVE-Shell running in the Emacs session, IDLWAVE will
@emph{query the shell} for compiled routines and their arguments.  This
happens automatically when routine information or completion is first
requested by the user, and each time an Emacs buffer is compiled with
@kbd{C-c C-d C-c}.  Though rarely necessary, the command @kbd{C-c C-i}
(@code{idlwave-update-routine-info}) can be used to update the shell
routine data.

@item
IDLWAVE can scan all or selected library source files and store the
result in a file which will be automatically loaded just like
@file{idlw-rinfo.el}. @xref{Library Catalog}, for information how to
scan library files.
@end enumerate

Loading routine and catalog information is a time consuming process.
Depending on the system and network configuration it can take up to 30
seconds.  In order to minimize the waiting time upon your first
completion or routine info command in a session, IDLWAVE uses Emacs idle
time to do the initialization in 5 steps, yielding to user input in
between.  If this gets into your way, set the variable
@code{idlwave-init-rinfo-when-idle-after} to 0 (zero).

@defopt idlwave-init-rinfo-when-idle-after (@code{10})
Seconds of idle time before routine info is automatically initialized.
@end defopt

@defopt idlwave-scan-all-buffers-for-routine-info (@code{t})
Non-@code{nil} means scan all buffers for IDL programs when updating
info.
@end defopt

@defopt idlwave-query-shell-for-routine-info (@code{t})
Non-@code{nil} means query the shell for info about compiled routines.
@end defopt

@defopt idlwave-auto-routine-info-updates
Controls under what circumstances routine info is updated automatically.
@end defopt

@node Library Catalog, Load-Path Shadows, Routine Information Sources, Sources of Routine Info
@appendixsec Library Catalog
@cindex Library scan
@cindex Library catalog
@cindex IDL library routine info
@cindex Windows
@cindex MacOS
@cindex IDL variable @code{!DIR}
@cindex @code{!DIR}, IDL variable


IDLWAVE can extract routine information from library modules and store
that information in a file.  To do this, the variable
@code{idlwave-libinfo-file} needs to contain the path to a file in an
existing directory (the default is @code{"~/.idlcat.el"}).  Since the
file will contain lisp code, its name should end in @file{.el}.  Under
Windows and MacOS, you also need to specify the search path for IDL
library files in the variable @code{idlwave-library-path}, and the
location of the IDL directory (the value of the @code{!DIR} system
variable) in the variable @code{idlwave-system-directory}, like
this@footnote{The initial @samp{+} leads to recursive expansion of the
path, just like in IDL}:

@lisp
(setq idlwave-library-path
        '("+c:/RSI/IDL54/lib/" "+c:/user/me/idllibs" ))
(setq idlwave-system-directory "c:/RSI/IDL54/")
@end lisp

@noindent Under GNU and UNIX, these values will be automatically inferred from
an IDLWAVE shell.

The command @kbd{M-x idlwave-create-libinfo-file} can then be used to
scan library files.  It brings up a widget in which you can select some
or all directories on the search path.  If you only want to have routine
and completion info of some libraries, it is sufficient to scan those
directories.  However, if you want IDLWAVE to detect possible name
conflicts with routines defined in other libraries, the whole pass
should be scanned. 

After selecting directories, click on the @w{@samp{[Scan & Save]}}
button in the widget to scan all files in the selected directories and
write the resulting routine information into the file
@code{idlwave-libinfo-file}.  In order to update the library information
from the same directories, call the command
@code{idlwave-update-routine-info} with a double prefix argument:
@w{@kbd{C-u C-u C-c C-i}}.  This will rescan files in the previously
selected directories, write an updated version of the libinfo file and
rebuild IDLWAVE's internal lists.  If you give three prefix arguments
@w{@kbd{C-u C-u C-u C-c C-i}}, updating will be done with a background
job@footnote{Unix systems only, I think.}.  You can continue to work,
and the library catalog will be re-read when it is ready.

A note of caution:  Depending on your local installation, the IDL
library can be very large.  Parsing it for routine information will take
time and loading this information into Emacs can require a
significant amount of memory.  However, having this information
available will be a great help.

@defopt idlwave-libinfo-file
File for routine information of the IDL library.
@end defopt

@defopt idlwave-library-path
IDL library path for Windows and MacOS.  Not needed under Unix.
@end defopt

@defopt idlwave-system-directory
The IDL system directory for Windows and MacOS.  Not needed under Unix.
@end defopt

@defopt idlwave-special-lib-alist
Alist of regular expressions matching special library directories.
@end defopt

@node Load-Path Shadows, Documentation Scan, Library Catalog, Sources of Routine Info
@appendixsec Load-Path Shadows
@cindex Load-path shadows
@cindex Shadows, load-path
@cindex Duplicate routines
@cindex Multiply defined routines
@cindex Routine definitions, multiple
@cindex Application, testing for shadowing
@cindex Buffer, testing for shadowing

IDLWAVE can compile a list of routines which are defined in several
different files.  Since one definition will hide (shadow) the others
depending on which file is compiled first, such multiple definitions are
called "load-path shadows".  IDLWAVE has several routines to scan for
load path shadows.  The output is placed into the special buffer
@file{*Shadows*}.  The format of the output is identical to the source
section of the routine info buffer (@pxref{Routine Info}).  The
different definitions of a routine are listed in the sequence of
@emph{likelihood of use}.  So the first entry will be most likely the
one you'll get if an unsuspecting command uses that routine.  Before
listing shadows, you should make sure that routine info is up-to-date by
pressing @kbd{C-c C-i}.  Here are the different routines:

@table @asis
@item @kbd{M-x idlwave-list-buffer-load-path-shadows}
This commands checks the names of all routines defined in the current
buffer for shadowing conflicts with other routines accessible to
IDLWAVE.  The command also has a key binding: @kbd{C-c C-b}
@item @kbd{M-x idlwave-list-shell-load-path-shadows}.
Checks all routines compiled under the shell for shadowing.  This is
very useful when you have written a complete application.  Just compile
the application, use @code{RESOLVE_ALL} to compile any routines used by
your code, update the routine info inside IDLWAVE with @kbd{C-c C-i} and
then check for shadowing.
@item @kbd{M-x idlwave-list-all-load-path-shadows}
This command checks all routines accessible to IDLWAVE for conflicts.
@end table

For these commands to work properly you should have scanned the entire
load path, not just selected directories.  Also, IDLWAVE should be able
to distinguish between the system library files (normally installed in
@file{/usr/local/rsi/idl/lib}) and any site specific or user specific
files.  Therefore, such local files should not be installed inside the
@file{lib} directory of the IDL directory.  This is also advisable for
many other reasons.

@cindex Windows
@cindex MacOS
@cindex IDL variable @code{!DIR}
@cindex @code{!DIR}, IDL variable
Users of Windows and MacOS also must set the variable
@code{idlwave-system-directory} to the value of the @code{!DIR} system
variable in IDL.  IDLWAVE appends @file{lib} to the value of this
variable and assumes that all files found on that path are system
routines.

Another way to find out if a specific routine has multiple definitions
on the load path is routine info display (@pxref{Routine Info}).

@node Documentation Scan,  , Load-Path Shadows, Sources of Routine Info
@appendixsec Documentation Scan 
@cindex @file{get_rinfo}
@cindex @file{idlw-rinfo.el}
@cindex @file{idlw-help.txt}
@cindex @file{idlw-help.el}
@cindex Scanning the documentation
@cindex Perl program, to create @file{idlw-rinfo.el}

IDLWAVE derives it knowledge about system routines from the IDL
manuals.  The file @file{idlw-rinfo.el} contains the routine information
for the IDL system routines.  The Online Help feature of IDLWAVE
requires ASCII versions of some IDL manuals to be available in a
specific format (@file{idlw-help.txt}), along with an Emacs-Lisp file
@file{idlw-help.el} with supporting code and pointers to the ASCII file.

All 3 files can be derived from the IDL documentation.  If you are
lucky, the maintainer of IDLWAVE will always have access to the newest
version of IDL and provide updates.  The IDLWAVE distribution also
contains the Perl program @file{get_rinfo} which constructs these files
by scanning selected files from the IDL documentation.  Instructions on
how to use @file{get_rinfo} are in the program itself.

One particularly frustrating situation occurs when a new IDL version is
released without the associated documentation updates.  Instead, a
@emph{What's New} file containing new and updated documentation is
shipped alongside the previous version's reference material.  The
@file{get_rinfo} script can merge this new information into the standard
help text and routine information, as long as it is pre-formatted in a
simple way.  See @file{get_rinfo} for more information.

@node Configuration Examples, Windows and MacOS, Sources of Routine Info, Top
@appendix Configuration Examples
@cindex Configuration examples
@cindex Example configuration
@cindex @file{.emacs}
@cindex Default settings, of options
@cindex Interview, with the maintainer

@noindent
@b{Question:} You have all these complicated configuration options in
your package, but which ones do @emph{you} as the maintainer actually
set in your own configuration?

@noindent
@b{Answer:} Not many, beyond custom key bindings.  I set most defaults
the way that seems best.  However, the default settings do not turn on
features which:

@itemize @minus
@item
are not self-evident (i.e. too magic) when used by an unsuspecting user.
@item
are too intrusive.
@item
will not work properly on all Emacs installations.
@item
break with widely used standards.
@item
use function or other non-standard keys.
@item
are purely personal customizations, like additional key bindings, and
library names.
@end itemize

@noindent To see what I mean, here is the @emph{entire} configuration
the old maintainer had in his @file{.emacs}:

@lisp
(setq idlwave-shell-debug-modifiers '(control shift)
      idlwave-store-inquired-class t
      idlwave-shell-automatic-start t
      idlwave-main-block-indent 2
      idlwave-init-rinfo-when-idle-after 2
      idlwave-help-dir "~/lib/emacs/idlwave"
      idlwave-special-lib-alist '(("/idl-astro/" . "AstroLib")
                                  ("/jhuapl/" . "JHUAPL-Lib")
                                  ("/dominik/lib/idl/" . "MyLib")))
@end lisp

However, if you are an Emacs power-user and want IDLWAVE to work
completely differently, you can change almost every aspect of it.  Here
is an example of a much more extensive configuration of IDLWAVE.  The
user is King!

@example
;;; Settings for IDLWAVE mode

(setq idlwave-block-indent 3)           ; Indentation settings
(setq idlwave-main-block-indent 3)
(setq idlwave-end-offset -3)
(setq idlwave-continuation-indent 1)
(setq idlwave-begin-line-comment "^;[^;]")  ; Leave ";" but not ";;" 
                                            ; anchored at start of line.
(setq idlwave-surround-by-blank t)      ; Turn on padding ops =,<,>
(setq idlwave-pad-keyword nil)          ; Remove spaces for keyword '='
(setq idlwave-expand-generic-end t)     ; convert END to ENDIF etc...
(setq idlwave-reserved-word-upcase t)   ; Make reserved words upper case
                                        ; (with abbrevs only)
(setq idlwave-abbrev-change-case nil)   ; Don't force case of expansions
(setq idlwave-hang-indent-regexp ": ")  ; Change from "- " for auto-fill
(setq idlwave-show-block nil)           ; Turn off blinking to begin
(setq idlwave-abbrev-move t)            ; Allow abbrevs to move point
(setq idlwave-query-class '((method-default . nil) ; No query for method
                            (keyword-default . nil); or keyword completion
                            ("INIT" . t)           ; except for these
                            ("CLEANUP" . t)
                            ("SETPROPERTY" .t)
                            ("GETPROPERTY" .t)))

;; Some setting can only be done from a mode hook.  Here is an example:
(add-hook 'idlwave-mode-hook
  (lambda ()
    (setq case-fold-search nil)          ; Make searches case sensitive
    ;; Run other functions here
    (font-lock-mode 1)                   ; Turn on font-lock mode
    (idlwave-auto-fill-mode 0)           ; Turn off auto filling

    ;; Pad with 1 space (if -n is used then make the
    ;; padding a minimum of n spaces.)  The defaults use -1
    ;; instead of 1.
    (idlwave-action-and-binding "=" '(idlwave-expand-equal 1 1))
    (idlwave-action-and-binding "<" '(idlwave-surround 1 1))
    (idlwave-action-and-binding ">" '(idlwave-surround 1 1 '(?-)))
    (idlwave-action-and-binding "&" '(idlwave-surround 1 1))

    ;; Only pad after comma and with exactly 1 space
    (idlwave-action-and-binding "," '(idlwave-surround nil 1))
    (idlwave-action-and-binding "&" '(idlwave-surround 1 1))

    ;; Pad only after `->', remove any space before the arrow
    (idlwave-action-and-binding "->"  '(idlwave-surround 0 -1 nil 2))

    ;; Set some personal bindings
    ;; (In this case, makes `,' have the normal self-insert behavior.)
    (local-set-key "," 'self-insert-command)
    (local-set-key [f5] 'idlwave-shell-break-here)
    (local-set-key [f6] 'idlwave-shell-clear-current-bp)

    ;; Create a newline, indenting the original and new line.
    ;; A similar function that does _not_ reindent the original
    ;; line is on "\C-j" (The default for emacs programming modes).
    (local-set-key "\n" 'idlwave-newline)
    ;; (local-set-key "\C-j" 'idlwave-newline) ; My preference.

    ;; Some personal abbreviations
    (define-abbrev idlwave-mode-abbrev-table  
      (concat idlwave-abbrev-start-char "wb") "widget_base()"
      (idlwave-keyword-abbrev 1))
    (define-abbrev idlwave-mode-abbrev-table  
      (concat idlwave-abbrev-start-char "on") "obj_new()"
      (idlwave-keyword-abbrev 1))
    ))

;;; Settings for IDLWAVE SHELL mode

(setq idlwave-shell-overlay-arrow "=>")        ; default is ">"
(setq idlwave-shell-use-dedicated-frame t)     ; Make a dedicated frame
(setq idlwave-shell-prompt-pattern "^WAVE> ")  ; default is "^IDL> "
(setq idlwave-shell-explicit-file-name "wave")
(setq idlwave-shell-process-name "wave")
(setq idlwave-shell-use-toolbar nil)           ; No toolbar

;; Most shell interaction settings can be done from the shell-mode-hook.
(add-hook 'idlwave-shell-mode-hook
          (lambda ()
            ;; Set up some custom key and mouse examine commands
            (idlwave-shell-define-key-both [s-down-mouse-2] 
                                 (idlwave-shell-mouse-examine 
                                  "print, size(___,/DIMENSIONS)"))
            (idlwave-shell-define-key-both [f9] (idlwave-shell-examine
                                       "print, size(___,/DIMENSIONS)"))
            (idlwave-shell-define-key-both [f10] (idlwave-shell-examine 
                                        "print,size(___,/TNAME)"))
            (idlwave-shell-define-key-both [f11] (idlwave-shell-examine
                                        "help,___,/STRUCTURE"))))
@end example

@ifhtml
<A NAME="WIN_MAC"></A>
@end ifhtml
@node Windows and MacOS, Index, Configuration Examples, Top
@appendix Windows and MacOS
@cindex Windows
@cindex MacOS

IDLWAVE was developed on a UNIX system.  However, due to the portability
of Emacs, much of IDLWAVE does also work under different operating
systems like Windows (with NTEmacs or NTXEmacs) or MacOS.

The only problem really is that RSI does not provide a command-line
version of IDL for Windows or MacOS with which IDLWAVE can
interact@footnote{Call your RSI representative and complain --- it
should be trivial for them to provide one.  And if enough people ask
for it, maybe they will.  The upcoming IDL for Mac OSX is slated to
have a command-line version.}.  Therefore the IDLWAVE Shell does not
work and you have to rely on IDLDE to run and debug your programs.
However, editing IDL source files with Emacs/IDLWAVE works with all
bells and whistles, including routine info, completion and fast online
help.  Only a small amount of additional information must be specified
in your .emacs file: the path names which, on a UNIX system, are
automatically gathered by talking to the IDL program.

Here is an example of the additional configuration needed for a Windows
system.  I am assuming that IDLWAVE has been installed in
@w{@samp{C:\Program Files\IDLWAVE}} and that IDL is installed in
@w{@samp{C:\RSI\IDL55}}.

@lisp
;; location of the lisp files (needed if IDLWAVE is not part of 
;; the X/Emacs installation)
(setq load-path (cons "c:/program files/IDLWAVE" load-path))

;; The location of the IDL library files, both from RSI and your own.
;; note that the initial "+" expands the path recursively
(setq idlwave-library-path
        '("+c:/RSI/IDL55/lib/" "+c:/user/me/idllibs" ))

;; location of the IDL system directory (try "print,!DIR")
(setq idlwave-system-directory "c:/RSI/IDL55/")

;; location of the IDLWAVE help files idlw-help.el and idlw-help.txt.
(setq idlwave-help-directory "c:/IDLWAVE")

;; file in which to store the user catalog info
(setq idlwave-libinfo-file "c:/IDLWAVE/idlcat.el")
@end lisp

@noindent Furthermore, Windows sometimes tries to outsmart you --- make
sure you check the following things:

@itemize @bullet
@item When you download the IDLWAVE distribution, make sure you save the 
files under the names @file{idlwave.tar.gz} and
@file{idlwave-help-tar.gz}.
@item Be sure that your software for untarring/ungzipping is @emph{NOT}
doing smart CR/LF conversion (WinZip users will find this in
Options:Configuration:Miscellaneous, change the setting, then re-open
the archive).  This adds one byte per line, throwing off the
byte-counts for the help file lookups and defeating fast online help lookup.
@item M-TAB switches among running programs --- use Esc-TAB
instead.
@item Other issues as yet unnamed...
@end itemize


@node Index,  , Windows and MacOS, Top
@unnumbered Index
@printindex cp

@bye