wip: a distilled snippet engine

2025-10-13 21:13:04 +00:00 · 2013-10-12 00:17:37 +01:00 · 2013-10-12 00:17:37 +01:00 · f00509a696
commit f00509a696
parent d963c41a14
1 changed files with 112 additions and 0 deletions
--- a/snippet.el
+++ b/snippet.el
@ -0,0 +1,112 @@
+;;; snippet.el --- yasnippet's snippet engine distilled  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2013  João Távora
+
+;; Author: João Távora <joaotavora@gmail.com>
+;; Keywords: convenience
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+
+(cl-defstruct (snippet--field (:constructor snippet--make-field (name parent-field)))
+  name
+  start end
+  parent-field
+  (mirrors '())
+  (transform nil)
+  (modified-p nil)
+  next)
+
+
+(cl-defstruct (snippet--mirror (:constructor snippet--make-mirror (source transform)))
+  source
+  start end
+  (transform nil)
+  parent-field
+  next
+  depth)
+
+(defun snippet--insert-field (field text)
+  (setf (snippet--field-start field) (point))
+  (when text (insert text))
+  (setf (snippet--field-end field) (point)))
+
+(defun snippet--insert-mirror (mirror)
+  (setf (snippet--mirror-start mirror) (point))
+  (insert (funcall (snippet--mirror-transform mirror)))
+  (setf (snippet--mirror-end mirror) (point)))
+
+
+(defmacro* define-snippet (name (&key obarray) &rest body)
+  (cl-flet ((field-p (form) (and (consp form) (eq (car form) 'field)))
+            (mirror-p (form) (and (consp form) (eq (car form) 'mirror)))
+            (make-field-sym (field-name) (make-symbol (format "field-%s"
+                                                              field-name)))
+            (make-mirror-sym (mirror-name field-name) (make-symbol (format "mirror-%s-of-%s"
+                                                                           mirror-name
+                                                                           field-name))))
+    `(defun ,name ()
+       (let* (,@(loop for form in (cl-remove-if-not #'field-p body)
+                      for field-sym = (make-field-sym (second form))
+                      collect `(,field-sym
+                                (snippet--make-field ,(second form) ,(third form))))
+              ,@(loop for form in (cl-remove-if-not #'mirror-p body)
+                      for mirror-sym = (make-mirror-sym i (second form))
+                      for source-field-sym = (make-field-sym (second form))
+                      for i from 1
+                      collect `(,mirror-sym
+                                (snippet--make-mirror ,source-field-sym
+                                                      #'(lambda ()
+                                                          (funcall
+                                                           #'(lambda (field-text)
+                                                               ,(third form))
+                                                           (snippet--field-text ,source-field-sym))))))
+              (start (point))
+              overlay)
+         ,@(loop with mirror-idx = 1
+                 for form in body
+                 collect (cond ((field-p form)
+                                `(snippet--insert-field ,(make-field-sym (second form))
+                                                        ,(third form)))
+                               ((mirror-p form)
+                                (prog1 `(snippet--insert-mirror ,(make-mirror-sym mirror-idx
+                                                                                  (second form)))
+                                  (incf mirror-idx)))
+                               (t
+                                `(insert ,form))))
+         (setq overlay (make-overlay start (point)))))))
+
+(define-snippet printf ()
+  "printf (\""
+  (field 1 "%s")
+  "\n"
+  (mirror 1 (if (string-match "%" field-text) "," "\);"))
+  (field 2)
+  (mirror 1 (if (string-match "%" field-text) "\);" "")))
+
+
+
+
+(provide 'snippet)
+
+;;; Local Variables:
+;;; lexical-binding: t
+;;; End:
+;;; snippet.el ends here