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Augment expression parser to handle conditional expressions.

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This commit is contained in:
Andreas Schwab 2002-03-06 15:12:01 +00:00
parent 8b5eabe078
commit 2dc2ec3d49
2 changed files with 37 additions and 7 deletions
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12
lisp/ChangeLog
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@ -1,3 +1,15 @@
2002-03-06 Andreas Schwab <schwab@suse.de>
* progmodes/hideif.el: Augment expression parser to handle
conditional expressions.
(hif-token-regexp): Also match `?' and `:'.
(hif-tokenize): Handle `?' and ':' as tokens.
(hif-expr): Parse conditional expressions.
(hif-or-expr): Parse `||' expressions.
(hif-and-expr): Renamed from hif-term.
(hif-conditional): New function to evaluate a conditional
expression.
2002-03-06 Gerd Moellmann <gerd@gnu.org>
* vc.el (vc-branch-part): Add autoload cookie. This function can

32
lisp/progmodes/hideif.el
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@ -1,6 +1,6 @@
;;; hideif.el --- hides selected code within ifdef
;; Copyright (C) 1988,1994,2001 Free Software Foundation, Inc.
;; Copyright (C) 1988,1994,2001, 2002 Free Software Foundation, Inc.
;; Author: Daniel LaLiberte <liberte@holonexus.org>
;; Maintainer: FSF
@ -309,7 +309,7 @@ that form should be displayed.")
;; pattern to match initial identifier, !, &&, ||, (, or ).
;; Added ==, + and -: garyo@avs.com 8/9/94
(defconst hif-token-regexp
"\\(&&\\|||\\|[!=]=\\|!\\|[()+-]\\|[<>]=?\\|\\w+\\)")
"\\(&&\\|||\\|[!=]=\\|!\\|[()+?:-]\\|[<>]=?\\|\\w+\\)")
(defun hif-tokenize (start end)
"Separate string between START and END into a list of tokens."
@ -342,6 +342,8 @@ that form should be displayed.")
((string-equal token "<=") 'hif-less-equal)
((string-equal token "+") 'hif-plus)
((string-equal token "-") 'hif-minus)
((string-equal token "?") 'hif-conditional)
((string-equal token ":") 'hif-colon)
((string-match "\\`[0-9]*\\'" token)
(string-to-number token))
(t (intern token)))
@ -368,15 +370,29 @@ that form should be displayed.")
(defun hif-expr ()
"Parse an expression as found in #if.
expr : term | expr '||' term."
(let ((result (hif-term)))
expr : or-expr | or-expr '?' expr ':' expr."
(let ((result (hif-or-expr))
middle)
(while (eq hif-token 'hif-conditional)
(hif-nexttoken)
(setq middle (hif-expr))
(if (eq hif-token 'hif-colon)
(progn
(hif-nexttoken)
(setq result (list 'hif-conditional result middle (hif-expr))))
(error "Error: unexpected token: %s" hif-token)))
result))
(defun hif-or-expr ()
"Parse n or-expr : and-expr | or-expr '||' and-expr."
(let ((result (hif-and-expr)))
(while (eq hif-token 'or)
(hif-nexttoken)
(setq result (list 'hif-or result (hif-term))))
(setq result (list 'hif-or result (hif-and-expr))))
result))
(defun hif-term ()
"Parse a term : eq-expr | term '&&' eq-expr."
(defun hif-and-expr ()
"Parse an and-expr : eq-expr | and-expr '&&' eq-expr."
(let ((result (hif-eq-expr)))
(while (eq hif-token 'and)
(hif-nexttoken)
@ -449,6 +465,8 @@ that form should be displayed.")
((null val) 0)
(t val)))
(defun hif-conditional (a b c)
(if (not (zerop (hif-mathify a))) (hif-mathify b) (hif-mathify c)))
(defun hif-and (a b)
(and (not (zerop (hif-mathify a))) (not (zerop (hif-mathify b)))))
(defun hif-or (a b)