From 9a9182ac472061d8bcbd72f13e5a076895e92b3b Mon Sep 17 00:00:00 2001
From: Zhang Chiyuan <pluskid@gmail.com>
Date: Mon, 3 Mar 2008 02:40:06 +0000
Subject: [PATCH] fundamental expansion implemented.

---
 yasnippet.el | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 yasnippet.el

diff --git a/yasnippet.el b/yasnippet.el
new file mode 100644
index 0000000..fe2df82
--- /dev/null
+++ b/yasnippet.el
@@ -0,0 +1,84 @@
+;;; yasnippet.el --- Yet another snippet extension for Emacs.
+
+;; Author: pluskid <pluskid@gmail.com>
+;; Version: 0.1
+
+;; This file 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 2, or (at your option)
+;; any later version.
+
+;; This file 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; see the file COPYING.  If not, write to
+;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Nothing.
+
+(require 'cl)
+
+(defvar yas/snippet-tables (make-hash-table)
+  "A hash table of snippet tables corresponding to each major-mode.")
+
+(defvar yas/key-syntax "w"
+  "Syntax of a key. This is used to determine the current key being 
+expanded.")
+
+
+(defun yas/snippet-table (mode)
+  "Get the snippet table corresponding to MODE."
+  (let ((table (gethash mode yas/snippet-tables)))
+    (unless table
+      (setq table (make-hash-table :test 'equal))
+      (puthash mode table yas/snippet-tables))
+    table))
+(defsubst yas/current-snippet-table ()
+  "Get the snippet table for current major-mode."
+  (yas/snippet-table major-mode))
+
+(defsubst yas/template (key snippet-table)
+  "Get template for KEY in SNIPPET-TABLE."
+  (gethash key snippet-table))
+
+(defun yas/current-key ()
+  "Get the key under current position."
+  (let ((start (point))
+	(end (point)))
+    (save-excursion
+      (skip-syntax-backward yas/key-syntax)
+      (setq start (point))
+      (list (buffer-substring-no-properties start end)
+	    start
+	    end))))
+
+(defun yas/expand-snippet (start end template)
+  "Expand snippet at current point. Text between START and END
+will be deleted before inserting template."
+  (delete-region start end)
+  (insert template))
+
+(defun yas/define (mode key template)
+  "Define a snippet. Expanding KEY into TEMPLATE."
+  (puthash key template (yas/snippet-table mode)))
+
+
+(defun yas/expand ()
+  "Expand a snippet. When a snippet is expanded, t is returned,
+otherwise, nil returned."
+  (interactive)
+  (multiple-value-bind (key start end) (yas/current-key)
+    (let ((template (yas/template key (yas/current-snippet-table))))
+      (if template
+	  (progn
+	    (yas/expand-snippet start end template)
+	    t)
+	nil))))
+
+(provide 'yasnippet)