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org-mode/lisp/ob-ref.el

243 lines
9.7 KiB
EmacsLisp

;;; ob-ref.el --- org-babel functions for referencing external data
;; Copyright (C) 2009, 2010 Free Software Foundation, Inc.
;; Author: Eric Schulte, Dan Davison
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org
;; Version: 7.01trans
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; Functions for referencing data from the header arguments of a
;; org-babel block. The syntax of such a reference should be
;; #+VAR: variable-name=file:resource-id
;; - variable-name :: the name of the variable to which the value
;; will be assigned
;; - file :: path to the file containing the resource, or omitted if
;; resource is in the current file
;; - resource-id :: the id or name of the resource
;; So an example of a simple src block referencing table data in the
;; same file would be
;; #+TBLNAME: sandbox
;; | 1 | 2 | 3 |
;; | 4 | org-babel | 6 |
;;
;; #+begin_src emacs-lisp :var table=sandbox
;; (message table)
;; #+end_src
;;; Code:
(require 'ob)
(eval-when-compile
(require 'cl))
(declare-function org-remove-if-not "org" (predicate seq))
(declare-function org-at-table-p "org" (&optional table-type))
(declare-function org-count "org" (CL-ITEM CL-SEQ))
(defun org-babel-ref-variables (params)
"Convert PARAMS to variable names and values.
Takes a parameter alist, and return an alist of variable names,
and the emacs-lisp representation of the related value."
(let ((assignments
(delq nil (mapcar (lambda (pair) (if (eq (car pair) :var) (cdr pair))) params)))
(others
(delq nil (mapcar (lambda (pair) (unless (eq :var (car pair)) pair)) params))))
(mapcar (lambda (assignment) (org-babel-ref-parse assignment)) assignments)))
(defvar org-babel-ref-split-regexp
"[ \f\t\n\r\v]*\\(.+?\\)[ \f\t\n\r\v]*=[ \f\t\n\r\v]*\\(.+\\)[ \f\t\n\r\v]*")
(defun org-babel-ref-parse (assignment &optional params)
"Parse a variable ASSIGNMENT in a header argument.
If the right hand side of the assignment has a literal value
return that value, otherwise interpret as a reference to an
external resource and find it's value using
`org-babel-ref-resolve-reference'. Return a list with two
elements. The first element of the list will be the name of the
variable, and the second will be an emacs-lisp representation of
the value of the variable."
(if (string-match org-babel-ref-split-regexp assignment)
(let ((var (match-string 1 assignment))
(ref (match-string 2 assignment)))
(cons (intern var)
((lambda (val)
(if (equal :ob-must-be-reference val)
(org-babel-ref-resolve-reference ref params)
val)) (org-babel-ref-literal ref))))))
(defun org-babel-ref-literal (ref)
"Return the value of REF if it is a literal value.
Determine if the right side of a header argument variable
assignment is a literal value or is a reference to some external
resource. REF should be a string of the right hand side of the
assignment. If REF is literal then return it's value, otherwise
return nil."
(let ((out (org-babel-read ref)))
(if (equal out ref)
(if (string-match "^\".+\"$" ref)
(read ref)
:ob-must-be-reference)
out)))
(defvar org-babel-library-of-babel)
(defun org-babel-ref-resolve-reference (ref &optional params)
"Resolve the reference REF and return its value."
(save-excursion
(let ((case-fold-search t)
type args new-refere new-referent result lob-info split-file split-ref
index index-row index-col)
;; if ref is indexed grab the indices -- beware nested indices
(when (and (string-match "\\[\\(.+\\)\\]" ref)
(let ((str (substring ref 0 (match-beginning 0))))
(= (org-count ?( str) (org-count ?) str))))
(setq index (match-string 1 ref))
(setq ref (substring ref 0 (match-beginning 0))))
;; assign any arguments to pass to source block
(when (string-match "^\\(.+?\\)\(\\(.*\\)\)$" ref)
(setq new-refere (match-string 1 ref))
(setq new-referent (match-string 2 ref))
;; (message "new-refere=%S, new-referent=%S" new-refere new-referent) ;; debugging
(when (> (length new-refere) 0)
(if (> (length new-referent) 0)
(setq args (mapcar (lambda (ref) (cons :var ref))
(org-babel-ref-split-args new-referent))))
;; (message "args=%S" args) ;; debugging
(setq ref new-refere)))
(when (string-match "^\\(.+\\):\\(.+\\)$" ref)
(setq split-file (match-string 1 ref))
(setq split-ref (match-string 2 ref))
(find-file split-file) (setq ref split-ref))
(save-restriction
(widen)
(goto-char (point-min))
(if (let ((result_regexp (concat "^[ \t]*#\\+\\(TBLNAME\\|RESNAME\\|RESULTS\\):[ \t]*"
(regexp-quote ref) "[ \t]*$"))
(regexp (concat org-babel-src-name-regexp
(regexp-quote ref) "\\(\(.*\)\\)?" "[ \t]*$")))
;; goto ref in the current buffer
(or (and (not args)
(or (re-search-forward result_regexp nil t)
(re-search-backward result_regexp nil t)))
(re-search-forward regexp nil t)
(re-search-backward regexp nil t)
;; check the Library of Babel
(setq lob-info (cdr (assoc (intern ref) org-babel-library-of-babel)))))
(unless lob-info (goto-char (match-beginning 0)))
;; ;; TODO: allow searching for names in other buffers
;; (setq id-loc (org-id-find ref 'marker)
;; buffer (marker-buffer id-loc)
;; loc (marker-position id-loc))
;; (move-marker id-loc nil)
(error "reference '%s' not found in this buffer" ref))
(if lob-info
(setq type 'lob)
(while (not (setq type (org-babel-ref-at-ref-p)))
(forward-line 1)
(beginning-of-line)
(if (or (= (point) (point-min)) (= (point) (point-max)))
(error "reference not found"))))
(setq params (org-babel-merge-params params args '((:results . "silent"))))
(setq result
(case type
('results-line (org-babel-read-result))
('table (org-babel-read-table))
('file (org-babel-read-link))
('source-block (org-babel-execute-src-block nil nil params))
('lob (org-babel-execute-src-block nil lob-info params))))
(if (symbolp result)
(format "%S" result)
(if (and index (listp result))
(org-babel-ref-index-list index result)
result))))))
(defun org-babel-ref-index-list (index lis)
"Return the subset of LIS indexed by INDEX.
Indices are 0 based and negative indices count from the end of
LIS, so 0 references the first element of LIS and -1 references
the last. If INDEX is separated by \",\"s then each \"portion\"
is assumed to index into the next deepest nesting or dimension.
A valid \"portion\" can consist of either an integer index, two
integers separated by a \":\" in which case the entire range is
returned, or an empty string or \"*\" both of which are
interpreted to mean the entire range and as such are equivalent
to \"0:-1\"."
(if (and (> (length index) 0) (string-match "^\\([^,]*\\),?" index))
(let ((ind-re "\\(\\([-[:digit:]]+\\):\\([-[:digit:]]+\\)\\|\*\\)")
(length (length lis))
(portion (match-string 1 index))
(remainder (substring index (match-end 0))))
(flet ((wrap (num) (if (< num 0) (+ length num) num))
(open (ls) (if (and (listp ls) (= (length ls) 1)) (car ls) ls)))
(open
(mapcar
(lambda (sub-lis) (org-babel-ref-index-list remainder sub-lis))
(if (or (= 0 (length portion)) (string-match ind-re portion))
(mapcar
(lambda (n) (nth n lis))
(apply 'number-sequence
(if (and (> (length portion) 0) (match-string 2 portion))
(list
(wrap (string-to-number (match-string 2 portion)))
(wrap (string-to-number (match-string 3 portion))))
(list (wrap 0) (wrap -1)))))
(list (nth (wrap (string-to-number portion)) lis)))))))
lis))
(defun org-babel-ref-split-args (arg-string)
"Split ARG-STRING into top-level arguments of balanced parenthesis."
(let ((index 0) (depth 0) (buffer "") holder return)
;; crawl along string, splitting at any ","s which are on the top level
(while (< index (length arg-string))
(setq holder (substring arg-string index (+ 1 index)))
(setq buffer (concat buffer holder))
(setq index (+ 1 index))
(cond
((string= holder ",")
(when (= depth 0)
(setq return (reverse (cons (substring buffer 0 -1) return)))
(setq buffer "")))
((or (string= holder "(") (string= holder "[")) (setq depth (+ depth 1)))
((or (string= holder ")") (string= holder "]")) (setq depth (- depth 1)))))
(mapcar #'org-babel-trim (reverse (cons buffer return)))))
(defvar org-bracket-link-regexp)
(defun org-babel-ref-at-ref-p ()
"Return the type of reference located at point.
Return nil if none of the supported reference types are found.
Supported reference types are tables and source blocks."
(cond ((org-at-table-p) 'table)
((looking-at "^[ \t]*#\\+BEGIN_SRC") 'source-block)
((looking-at org-bracket-link-regexp) 'file)
((looking-at org-babel-result-regexp) 'results-line)))
(provide 'ob-ref)
;; arch-tag: ace4a4f4-ea38-4dac-8fe6-6f52fcc43b6d
;;; ob-ref.el ends here