;;; ob-m4.el --- Babel Functions for m4 scripts -*- lexical-binding: t; -*- ;; Copyright (C) 2015-2018 Free Software Foundation, Inc. ;; Author: Brad Knotwell ;; Keywords: literate programming, reproducible research ;; Version: 0.1.0 ;; 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 . ;;; Commentary: ;; Provides a way to evaluate m4 scripts in Org mode. ;;; Usage: ;; Add to your Emacs config: ;; (org-babel-do-load-languages ;; 'org-babel-load-languages ;; '((m4 . t))) ;; In addition to the normal header arguments, ob-m4 also provides ;; two specific options: ;; :cmd-line -- allows a user to append arguments to the call ;; :prefix-buildins -- calls with the -P option to automatically ;; prefix all built-in macros with 'm4_' ;; Note: it is a bad idea to explicitly pass the "-P" option in ;; :cmd-line to enable prefixing as any arguments specified via ;; :var NAME=value will be prefixed incorrectly. ;; ;; Explaining this with a bit more detail, all :var NAME=value arguments are ;; prepended to the body as definitions: ;; define(NAME,value) ;; or ;; m4_define(NAME,value) iff :prefix-builtins is set ;; ;; Note: the :prefix-builtin option is incompatible with Posix ;; compliant m4 implementations. This is fine for two reasons: ;; * anyone using a Posix compliant utility is fine by default as ;; the -P option is omitted ;; * GNU's m4 implementation is (essentially) standard at this point (require 'ob) (defvar org-babel-m4-command "m4" "Name of the m4 executable command.") (defvar org-babel-tangle-lang-exts) (add-to-list 'org-babel-tangle-lang-exts '("m4" . "m4")) (defconst org-babel-header-args:m4 '((:cmd-line . :any) (:prefix-builtins)) "M4 specific header arguments.") (defvar org-babel-default-header-args:m4 '() "Default arguments for evaluating a m4 source block.") ;; build the passed-in macro definitions as a single string to prepend to the body ;; the hocus-pocus with :prefix-builtins is necessary for the -P option to work (defun __org-babel-m4-prefix (params) (if (assq :prefix-builtins params) "m4_")) (defun org-babel--variable-assignment:m4_generic (params varname values) (concat (__org-babel-m4-prefix params) "define(" (format "%s" varname) "," (format "%s" values) ")" (__org-babel-m4-prefix params) "dnl\n")) (defun org-babel--variable-assignment:m4_list (params varname values) (concat (__org-babel-m4-prefix params) "define(" (format "%s,[" varname) (mapconcat (lambda (value) (if (= (length value) 1) (format "%s" (car value)) (concat "[" (mapconcat (lambda (x) (format "%s" x)) value ",") "]"))) values ",") "])" (__org-babel-m4-prefix params) "dnl\n")) (defun org-babel--variable-assignments:m4 (params varnames values) "Represent the parameters as m4 definitions" (pcase values (`(,_ . ,_) (org-babel--variable-assignment:m4_list params varnames values)) (_ (org-babel--variable-assignment:m4_generic params varnames values)))) (defun org-babel-variable-assignments:m4 (params) (apply 'concat (mapcar (lambda (pair) (org-babel--variable-assignments:m4 params (car pair) (cdr pair))) (org-babel--get-vars params)))) ;; required to make tangling work ;; the final "\n" is required to make m4 work as the body doesn't end in a newline (defun org-babel-expand-body:m4 (body params) "Expand BODY according to PARAMS, return the expanded body." (concat (org-babel-variable-assignments:m4 params) body "\n")) (defun org-babel-execute:m4 (body params) "Execute a block of m4 code with Org Babel. BODY is the source inside a m4 source block and PARAMS is an association list over the source block configurations. This function is called by `org-babel-execute-src-block'." (message "executing m4 source code block") (let* ((result-params (cdr (assq :result-params params))) (cmd-line (cdr (assq :cmd-line params))) (prefix-builtins (assq :prefix-builtins params)) (code-file (let ((file (org-babel-temp-file "m4-"))) (with-temp-file file (insert (org-babel-expand-body:m4 body params) file)) file)) (stdin (let ((stdin (cdr (assq :stdin params)))) (when stdin (let ((tmp (org-babel-temp-file "m4-stdin-")) (res (org-babel-ref-resolve stdin))) (with-temp-file tmp (insert res)) tmp)))) (cmd (mapconcat #'identity (remq nil (list org-babel-m4-command cmd-line (if prefix-builtins "-P") "<" code-file)) " "))) (org-babel-reassemble-table (let ((results (cond (stdin (with-temp-buffer (call-process-shell-command cmd stdin (current-buffer)) (buffer-string))) (t (org-babel-eval cmd ""))))) (when results (org-babel-result-cond result-params results (let ((tmp (org-babel-temp-file "m4-results-"))) (with-temp-file tmp (insert results)) (org-babel-import-elisp-from-file tmp))))) (org-babel-pick-name (cdr (assq :colname-names params)) (cdr (assq :colnames params))) (org-babel-pick-name (cdr (assq :rowname-names params)) (cdr (assq :rownames params)))))) (provide 'ob-m4) ;;; ob-m4.el ends here ;; Test examples below: ;; ;; ;; #+begin_src m4 :results output :var XXXX='hello' :var YYYY='world' ;; define(this1, one will expand)dnl ;; m4_define(this2,one will not expand)m4_dnl ;; this1 ;; this2 ;; XXXX ;; YYYY ;; ZZZZ ;; #+end_src ;; #+RESULTS: ;; : m4_define(this2,one will not expand)m4_dnl ;; : one will expand ;; : this2 ;; : hello ;; : world ;; : ZZZZ ;; #+begin_src m4 :prefix-builtins :results output :var XXXX='hello' :var YYYY='world' ;; define(this1, one will not expand)dnl ;; m4_define(this2,one will expand)m4_dnl ;; this1 ;; this2 ;; XXXX ;; YYYY ;; ZZZZ ;; #+end_src ;; #+RESULTS: ;; : define(this1, one will not expand)dnl ;; : this1 ;; : one will expand ;; : hello ;; : world ;; : ZZZZ