lisp/ob-perl.el

   1 ;;; ob-perl.el --- Babel Functions for Perl          -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2009-2018 Free Software Foundation, Inc.
   4
   5 ;; Authors: Dan Davison
   6 ;;       Eric Schulte
   7 ;; Keywords: literate programming, reproducible research
   8 ;; Homepage: https://orgmode.org
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; Org-Babel support for evaluating perl source code.
  28
  29 ;;; Code:
  30 (require 'ob)
  31
  32 (defvar org-babel-tangle-lang-exts)
  33 (add-to-list 'org-babel-tangle-lang-exts '("perl" . "pl"))
  34
  35 (defvar org-babel-default-header-args:perl '())
  36
  37 (defvar org-babel-perl-command "perl"
  38   "Name of command to use for executing perl code.")
  39
  40 (defun org-babel-execute:perl (body params)
  41   "Execute a block of Perl code with Babel.
  42 This function is called by `org-babel-execute-src-block'."
  43   (let* ((session (cdr (assq :session params)))
  44          (result-params (cdr (assq :result-params params)))
  45          (result-type (cdr (assq :result-type params)))
  46          (full-body (org-babel-expand-body:generic
  47                      body params (org-babel-variable-assignments:perl params)))
  48          (session (org-babel-perl-initiate-session session)))
  49     (org-babel-reassemble-table
  50      (org-babel-perl-evaluate session full-body result-type result-params)
  51      (org-babel-pick-name
  52       (cdr (assq :colname-names params)) (cdr (assq :colnames params)))
  53      (org-babel-pick-name
  54       (cdr (assq :rowname-names params)) (cdr (assq :rownames params))))))
  55
  56 (defun org-babel-prep-session:perl (_session _params)
  57   "Prepare SESSION according to the header arguments in PARAMS."
  58   (error "Sessions are not supported for Perl"))
  59
  60 (defun org-babel-variable-assignments:perl (params)
  61   "Return list of perl statements assigning the block's variables."
  62   (mapcar
  63    (lambda (pair)
  64      (org-babel-perl--var-to-perl (cdr pair) (car pair)))
  65    (org-babel--get-vars params)))
  66
  67 ;; helper functions
  68
  69 (defvar org-babel-perl-var-wrap "q(%s)"
  70   "Wrapper for variables inserted into Perl code.")
  71
  72 (defvar org-babel-perl--lvl)
  73 (defun org-babel-perl--var-to-perl (var &optional varn)
  74   "Convert an elisp value to a perl variable.
  75 The elisp value, VAR, is converted to a string of perl source code
  76 specifying a var of the same value."
  77   (if varn
  78       (let ((org-babel-perl--lvl 0) (lvar (listp var)))
  79         (concat "my $" (symbol-name varn) "=" (when lvar "\n")
  80                 (org-babel-perl--var-to-perl var)
  81                 ";\n"))
  82     (let ((prefix (make-string (* 2 org-babel-perl--lvl) ?\ )))
  83       (concat prefix
  84               (if (listp var)
  85                   (let ((org-babel-perl--lvl (1+ org-babel-perl--lvl)))
  86                     (concat "[\n"
  87                             (mapconcat #'org-babel-perl--var-to-perl var "")
  88                             prefix "]"))
  89                 (format "q(%s)" var))
  90               (unless (zerop org-babel-perl--lvl) ",\n")))))
  91
  92 (defvar org-babel-perl-buffers '(:default . nil))
  93
  94 (defun org-babel-perl-initiate-session (&optional _session _params)
  95   "Return nil because sessions are not supported by perl."
  96   nil)
  97
  98 (defvar org-babel-perl-wrapper-method "{
  99     my $babel_sub = sub {
 100         %s
 101     };
 102     open my $BOH, qq(>%s) or die qq(Perl: Could not open output file.$/);
 103     my $rv = &$babel_sub();
 104     my $rt = ref $rv;
 105     select $BOH;
 106     if (qq(ARRAY) eq $rt) {
 107         local $\\=$/;
 108         local $,=qq(\t);
 109         foreach my $rv ( @$rv ) {
 110             my $rt = ref $rv;
 111             if (qq(ARRAY) eq $rt) {
 112                 print @$rv;
 113             } else {
 114                 print $rv;
 115             }
 116         }
 117     } else {
 118         print $rv;
 119     }
 120 }")
 121
 122 (defvar org-babel-perl-preface nil)
 123
 124 (defvar org-babel-perl-pp-wrapper-method
 125   nil)
 126
 127 (defun org-babel-perl-evaluate (session ibody &optional result-type result-params)
 128   "Pass BODY to the Perl process in SESSION.
 129 If RESULT-TYPE equals `output' then return a list of the outputs
 130 of the statements in BODY, if RESULT-TYPE equals `value' then
 131 return the value of the last statement in BODY, as elisp."
 132   (when session (error "Sessions are not supported for Perl"))
 133   (let* ((body (concat org-babel-perl-preface ibody))
 134          (tmp-file (org-babel-temp-file "perl-"))
 135          (tmp-babel-file (org-babel-process-file-name
 136                           tmp-file 'noquote)))
 137     (let ((results
 138            (pcase result-type
 139              (`output
 140               (with-temp-file tmp-file
 141                 (insert
 142                  (org-babel-eval org-babel-perl-command body))
 143                 (buffer-string)))
 144              (`value
 145               (org-babel-eval org-babel-perl-command
 146                               (format org-babel-perl-wrapper-method
 147                                       body tmp-babel-file))))))
 148       (when results
 149         (org-babel-result-cond result-params
 150           (org-babel-eval-read-file tmp-file)
 151           (org-babel-import-elisp-from-file tmp-file '(16)))))))
 152
 153 (provide 'ob-perl)
 154
 155
 156
 157 ;;; ob-perl.el ends here