Merge pull request #571 from PhilHudson/master

[gnu-emacs-elpa] / yasnippet.el

diff --git a/yasnippet.el b/yasnippet.el
index 93eceb24a247c93e6154b9e89155028738af7196..45702e4595ad788c92845d986b0f2864556b4e6a 100644 (file)
--- a/yasnippet.el
+++ b/yasnippet.el
@@ -1,6 +1,6 @@
 ;;; yasnippet.el --- Yet another snippet extension for Emacs.
 
 ;;; yasnippet.el --- Yet another snippet extension for Emacs.
 

-;; Copyright (C) 2008-2013 Free Software Foundation, Inc.
+;; Copyright (C) 2008-2013, 2015 Free Software Foundation, Inc.

 ;; Authors: pluskid <pluskid@gmail.com>,  João Távora <joaotavora@gmail.com>
 ;; Maintainer: João Távora <joaotavora@gmail.com>
 ;; Version: 0.8.1
 ;; Authors: pluskid <pluskid@gmail.com>,  João Távora <joaotavora@gmail.com>
 ;; Maintainer: João Távora <joaotavora@gmail.com>
 ;; Version: 0.8.1


@@ -41,7 +41,7 @@
 ;;           stored.  Can also be a list of directories.  In that case,
 ;;           when used for bulk (re)loading of snippets (at startup or
 ;;           via `yas-reload-all'), directories appearing earlier in
 ;;           stored.  Can also be a list of directories.  In that case,
 ;;           when used for bulk (re)loading of snippets (at startup or
 ;;           via `yas-reload-all'), directories appearing earlier in

-;;           the list shadow other dir's snippets.  Also, the first
+;;           the list override other dir's snippets.  Also, the first

 ;;           directory is taken as the default for storing the user's
 ;;           new snippets.
 ;;
 ;;           directory is taken as the default for storing the user's
 ;;           new snippets.
 ;;


@@ -130,8 +130,7 @@
 ;;; Code:
 
 (require 'cl)
 ;;; Code:
 
 (require 'cl)

-(eval-and-compile
-  (require 'cl-lib))
+(require 'cl-lib)

 (require 'easymenu)
 (require 'help-mode)
 
 (require 'easymenu)
 (require 'help-mode)
 


@@ -149,23 +148,28 @@
 
 (defgroup yasnippet nil
   "Yet Another Snippet extension"
 
 (defgroup yasnippet nil
   "Yet Another Snippet extension"

+  :prefix "yas-"

   :group 'editing)
 
   :group 'editing)
 

-(defvar yas--load-file-name load-file-name
-  "Store the filename that yasnippet.el was originally loaded from.")
+(defvar yas-installed-snippets-dir nil)
+(setq yas-installed-snippets-dir
+      (when load-file-name
+        (concat (file-name-directory load-file-name) "snippets")))

 
 (defcustom yas-snippet-dirs (remove nil
                                     (list "~/.emacs.d/snippets"
 
 (defcustom yas-snippet-dirs (remove nil
                                     (list "~/.emacs.d/snippets"

-                                          (when yas--load-file-name
-                                            (concat (file-name-directory yas--load-file-name) "snippets"))))
-  "Directory or list of snippet dirs for each major mode.
-
-The directory where user-created snippets are to be stored.  Can
-also be a list of directories.  In that case, when used for
-bulk (re)loading of snippets (at startup or via
-`yas-reload-all'), directories appearing earlier in the list
-shadow other dir's snippets.  Also, the first directory is taken
-as the default for storing the user's new snippets."
+                                          'yas-installed-snippets-dir))
+  "List of top-level snippet directories.
+
+Each element, a string or a symbol whose value is a string,
+designates a top-level directory where per-mode snippet
+directories can be found.
+
+Elements appearing earlier in the list override later elements'
+snippets.
+
+The first directory is taken as the default for storing snippet's
+created with `yas-new-snippet'. "

   :type '(choice (string :tag "Single directory (string)")
                  (repeat :args (string) :tag "List of directories (strings)"))
   :group 'yasnippet
   :type '(choice (string :tag "Single directory (string)")
                  (repeat :args (string) :tag "List of directories (strings)"))
   :group 'yasnippet


@@ -179,8 +183,18 @@ as the default for storing the user's new snippets."
                (yas-reload-all)))))
 
 (defun yas-snippet-dirs ()
                (yas-reload-all)))))
 
 (defun yas-snippet-dirs ()

-  "Return `yas-snippet-dirs' (which see) as a list."
-  (if (listp yas-snippet-dirs) yas-snippet-dirs (list yas-snippet-dirs)))
+  "Return variable `yas-snippet-dirs' as list of strings."
+  (cl-loop for e in (if (listp yas-snippet-dirs)
+                        yas-snippet-dirs
+                      (list yas-snippet-dirs))
+           collect
+           (cond ((stringp e) e)
+                 ((and (symbolp e)
+                       (boundp e)
+                       (stringp (symbol-value e)))
+                  (symbol-value e))
+                 (t
+                  (error "[yas] invalid element %s in `yas-snippet-dirs'" e)))))

 
 (defvaralias 'yas/root-directory 'yas-snippet-dirs)
 
 
 (defvaralias 'yas/root-directory 'yas-snippet-dirs)
 


@@ -275,7 +289,7 @@ next field"
   `yas-expand' returns nil)
 
 - A Lisp form (apply COMMAND . ARGS) means interactively call
   `yas-expand' returns nil)
 
 - A Lisp form (apply COMMAND . ARGS) means interactively call

-  COMMAND, if ARGS is non-nil, call COMMAND non-interactively
+  COMMAND. If ARGS is non-nil, call COMMAND non-interactively

   with ARGS as arguments."
   :type '(choice (const :tag "Call previous command"  call-other-command)
                  (const :tag "Do nothing"             return-nil))
   with ARGS as arguments."
   :type '(choice (const :tag "Call previous command"  call-other-command)
                  (const :tag "Do nothing"             return-nil))


@@ -512,10 +526,6 @@ snippet itself contains a condition that returns the symbol
 (defvar yas--menu-table (make-hash-table)
   "A hash table of MAJOR-MODE symbols to menu keymaps.")
 
 (defvar yas--menu-table (make-hash-table)
   "A hash table of MAJOR-MODE symbols to menu keymaps.")
 

-(defvar yas--known-modes
-  '(ruby-mode rst-mode markdown-mode)
-  "A list of mode which is well known but not part of Emacs.")
-

 (defvar yas--escaped-characters
   '(?\\ ?` ?\" ?' ?$ ?} ?{ ?\( ?\))
   "List of characters which *might* need to be escaped.")
 (defvar yas--escaped-characters
   '(?\\ ?` ?\" ?' ?$ ?} ?{ ?\( ?\))
   "List of characters which *might* need to be escaped.")


@@ -545,7 +555,7 @@ snippet itself contains a condition that returns the symbol
 
 (defun yas--snippet-next-id ()
   (let ((id yas--snippet-id-seed))
 
 (defun yas--snippet-next-id ()
   (let ((id yas--snippet-id-seed))

-    (incf yas--snippet-id-seed)
+    (cl-incf yas--snippet-id-seed)

     id))
 
 \f
     id))
 
 \f


@@ -902,7 +912,7 @@ Honour `yas-dont-activate', which see."
 \f
 ;;; Internal structs for template management
 
 \f
 ;;; Internal structs for template management
 

-(defstruct (yas--template (:constructor yas--make-blank-template))
+(defstruct (yas--template (:constructor yas--make-template))

   "A template for a snippet."
   key
   content
   "A template for a snippet."
   key
   content


@@ -918,16 +928,6 @@ Honour `yas-dont-activate', which see."
   table
   )
 
   table
   )
 

-(defun yas--populate-template (template &rest args)
-  "Helper function to populate TEMPLATE with properties."
-  (while args
-    (aset template
-          (position (intern (substring (symbol-name (car args)) 1))
-                    (mapcar #'car (get 'yas--template 'cl-struct-slots)))
-          (second args))
-    (setq args (cddr args)))
-  template)
-

 (defstruct (yas--table (:constructor yas--make-snippet-table (name)))
   "A table to store snippets for a particular mode.
 
 (defstruct (yas--table (:constructor yas--make-snippet-table (name)))
   "A table to store snippets for a particular mode.
 


@@ -1243,12 +1243,14 @@ Returns (TEMPLATES START END). This function respects
                            'again)
                  (setq methods (cdr methods))))
               (t
                            'again)
                  (setq methods (cdr methods))))
               (t

-               (error "[yas] invalid element in `yas-key-syntaxes'")))
-        (setq templates
-              (mapcan #'(lambda (table)
-                          (yas--fetch table (buffer-substring-no-properties (point)
-                                                                            original)))
-                      (yas--get-snippet-tables))))
+               (yas--warning "Warning invalid element %s in `yas-key-syntaxes'" method)))
+        (let ((possible-key (buffer-substring-no-properties (point) original)))
+          (save-excursion
+            (goto-char original)
+            (setq templates
+                  (mapcan #'(lambda (table)
+                              (yas--fetch table possible-key))
+                          (yas--get-snippet-tables))))))

       (when templates
         (list templates (point) original)))))
 
       (when templates
         (list templates (point) original)))))
 


@@ -1267,16 +1269,6 @@ Returns (TEMPLATES START END). This function respects
 \f
 ;;; Internal functions and macros:
 
 \f
 ;;; Internal functions and macros:
 

-(defun yas--real-mode? (mode)
-  "Try to find out if MODE is a real mode.
-
-The MODE bound to a function (like `c-mode') is considered real
-mode.  Other well known mode like `ruby-mode' which is not part of
-Emacs might not bound to a function until it is loaded.  So
-yasnippet keeps a list of modes like this to help the judgment."
-  (or (fboundp mode)
-      (find mode yas--known-modes)))
-

 (defun yas--handle-error (err)
   "Handle error depending on value of `yas-good-grace'."
   (let ((msg (yas--format "elisp error: %s" (error-message-string err))))
 (defun yas--handle-error (err)
   "Handle error depending on value of `yas-good-grace'."
   (let ((msg (yas--format "elisp error: %s" (error-message-string err))))


@@ -1618,20 +1610,19 @@ Optional PROMPT sets the prompt to use."
          (uuid (or (ninth snippet)
                   name))
          (template (or (gethash uuid (yas--table-uuidhash snippet-table))
          (uuid (or (ninth snippet)
                   name))
          (template (or (gethash uuid (yas--table-uuidhash snippet-table))

-                       (yas--make-blank-template))))
+                       (yas--make-template :uuid uuid
+                                           :table snippet-table))))

     ;; X) populate the template object
     ;;
     ;; X) populate the template object
     ;;

-    (yas--populate-template template
-                           :table       snippet-table
-                           :key         key
-                           :content     (second snippet)
-                           :name        (or name key)
-                           :group       group
-                           :condition   condition
-                           :expand-env  (sixth snippet)
-                           :file        (seventh snippet)
-                           :keybinding  keybinding
-                           :uuid         uuid)
+    (setf (yas--template-key template)        key)
+    (setf (yas--template-content template)    (second snippet))
+    (setf (yas--template-name template)       (or name key))
+    (setf (yas--template-group template)      group)
+    (setf (yas--template-condition template)  condition)
+    (setf (yas--template-expand-env template) (sixth snippet))
+    (setf (yas--template-file template)       (seventh snippet))
+    (setf (yas--template-keybinding template) keybinding)
+

     ;; X) Update this template in the appropriate table. This step
     ;;    also will take care of adding the key indicators in the
     ;;    templates menu entry, if any
     ;; X) Update this template in the appropriate table. This step
     ;;    also will take care of adding the key indicators in the
     ;;    templates menu entry, if any


@@ -1736,36 +1727,44 @@ With prefix argument USE-JIT do jit-loading of snippets."
          current-prefix-arg t))
   (unless yas-snippet-dirs
     (setq yas-snippet-dirs top-level-dir))
          current-prefix-arg t))
   (unless yas-snippet-dirs
     (setq yas-snippet-dirs top-level-dir))

-  (dolist (dir (yas--subdirs top-level-dir))
-    (let* ((major-mode-and-parents (yas--compute-major-mode-and-parents
-                                    (concat dir "/dummy")))
-           (mode-sym (car major-mode-and-parents))
-           (parents (cdr major-mode-and-parents)))
-      ;; Attention: The parents and the menus are already defined
-      ;; here, even if the snippets are later jit-loaded.
-      ;;
-      ;; * We need to know the parents at this point since entering a
-      ;;   given mode should jit load for its parents
-      ;;   immediately. This could be reviewed, the parents could be
-      ;;   discovered just-in-time-as well
-      ;;
-      ;; * We need to create the menus here to support the `full'
-      ;;   option to `yas-use-menu' (all known snippet menus are shown to the user)
-      ;;
-      (yas--define-parents mode-sym parents)
-      (yas--menu-keymap-get-create mode-sym)
-      (let ((fun `(lambda () ;; FIXME: Simulating lexical-binding.
-                    (yas--load-directory-1 ',dir ',mode-sym))))
-        (if (and use-jit
-                 (not (some #'(lambda (buffer)
-                                (with-current-buffer buffer
-                                  ;; FIXME: Shouldn't this use derived-mode-p?
-                                  (when (eq major-mode mode-sym)
-                                    (yas--message 3 "Discovered there was already %s in %s" buffer mode-sym)
-                                    t)))
-                            (buffer-list))))
-            (yas--schedule-jit mode-sym fun)
-            (funcall fun)))))
+  (let ((impatient-buffers))
+    (dolist (dir (yas--subdirs top-level-dir))
+      (let* ((major-mode-and-parents (yas--compute-major-mode-and-parents
+                                      (concat dir "/dummy")))
+             (mode-sym (car major-mode-and-parents))
+             (parents (cdr major-mode-and-parents)))
+        ;; Attention: The parents and the menus are already defined
+        ;; here, even if the snippets are later jit-loaded.
+        ;;
+        ;; * We need to know the parents at this point since entering a
+        ;;   given mode should jit load for its parents
+        ;;   immediately. This could be reviewed, the parents could be
+        ;;   discovered just-in-time-as well
+        ;;
+        ;; * We need to create the menus here to support the `full'
+        ;;   option to `yas-use-menu' (all known snippet menus are shown to the user)
+        ;;
+        (yas--define-parents mode-sym parents)
+        (yas--menu-keymap-get-create mode-sym)
+        (let ((fun `(lambda () ;; FIXME: Simulating lexical-binding.
+                      (yas--load-directory-1 ',dir ',mode-sym))))
+          (if use-jit
+              (yas--schedule-jit mode-sym fun)
+            (funcall fun)))
+        ;; Look for buffers that are already in `mode-sym', and so
+        ;; need the new snippets immediately...
+        ;; 
+        (when use-jit 
+          (cl-loop for buffer in (buffer-list)
+                   do (with-current-buffer buffer
+                        (when (eq major-mode mode-sym)
+                          (yas--message 3 "Discovered there was already %s in %s" buffer mode-sym)
+                          (push buffer impatient-buffers)))))))
+    ;; ...after TOP-LEVEL-DIR has been completely loaded, call
+    ;; `yas--load-pending-jits' in these impatient buffers.
+    ;; 
+    (cl-loop for buffer in impatient-buffers
+             do (with-current-buffer buffer (yas--load-pending-jits))))

   (when interactive
     (yas--message 3 "Loaded snippets from %s." top-level-dir)))
 
   (when interactive
     (yas--message 3 "Loaded snippets from %s." top-level-dir)))
 


@@ -1917,10 +1916,6 @@ foo\"bar\\! -> \"foo\\\"bar\\\\!\""
 \f
 ;;; Snippet compilation function
 
 \f
 ;;; Snippet compilation function
 

-(defun yas--initialize ()
-  "For backward compatibility, enable `yas-minor-mode' globally."
-  (yas-global-mode 1))
-

 (defun yas-compile-directory (top-level-dir)
   "Create .yas-compiled-snippets.el files under subdirs of TOP-LEVEL-DIR.
 
 (defun yas-compile-directory (top-level-dir)
   "Create .yas-compiled-snippets.el files under subdirs of TOP-LEVEL-DIR.
 


@@ -2065,11 +2060,10 @@ omitted from MODE's menu, even if they're manually loaded."
                         hash)
     (dolist (uuid omit-items)
       (let ((template (or (gethash uuid hash)
                         hash)
     (dolist (uuid omit-items)
       (let ((template (or (gethash uuid hash)

-                          (yas--populate-template (puthash uuid
-                                                           (yas--make-blank-template)
-                                                           hash)
-                                                  :table table
-                                                  :uuid uuid))))
+                          (puthash uuid
+                                   (yas--make-template :table table
+                                                       :uuid uuid)
+                                   hash))))

         (setf (yas--template-menu-binding-pair template) (cons nil :none))))))
 
 (defun yas--define-menu-1 (table menu-keymap menu uuidhash &optional group-list)
         (setf (yas--template-menu-binding-pair template) (cons nil :none))))))
 
 (defun yas--define-menu-1 (table menu-keymap menu uuidhash &optional group-list)


@@ -2077,12 +2071,12 @@ omitted from MODE's menu, even if they're manually loaded."
   (dolist (e (reverse menu))
     (cond ((eq (first e) 'yas-item)
            (let ((template (or (gethash (second e) uuidhash)
   (dolist (e (reverse menu))
     (cond ((eq (first e) 'yas-item)
            (let ((template (or (gethash (second e) uuidhash)

-                               (yas--populate-template (puthash (second e)
-                                                               (yas--make-blank-template)
-                                                               uuidhash)
-                                                      :table table
-                                                      :perm-group group-list
-                                                      :uuid (second e)))))
+                               (puthash (second e)
+                                        (yas--make-template
+                                         :table table
+                                         :perm-group group-list
+                                         :uuid (second e))
+                                        uuidhash))))

              (define-key menu-keymap (vector (gensym))
                (car (yas--template-menu-binding-pair-get-create template :stay)))))
           ((eq (first e) 'yas-submenu)
              (define-key menu-keymap (vector (gensym))
                (car (yas--template-menu-binding-pair-get-create template :stay)))))
           ((eq (first e) 'yas-submenu)


@@ -2224,8 +2218,19 @@ Common gateway for `yas-expand-from-trigger-key' and
   (cond ((eq yas-fallback-behavior 'return-nil)
          ;; return nil
          nil)
   (cond ((eq yas-fallback-behavior 'return-nil)
          ;; return nil
          nil)

+        ((eq yas-fallback-behavior 'yas--fallback)
+         (error (concat "yasnippet fallback loop!\n"
+                        "This can happen when you bind `yas-expand' "
+                        "outside of the `yas-minor-mode-map'.")))

         ((eq yas-fallback-behavior 'call-other-command)
         ((eq yas-fallback-behavior 'call-other-command)

-         (let* ((beyond-yasnippet (yas--keybinding-beyond-yasnippet)))
+         (let* ((yas-fallback-behavior 'yas--fallback)
+                ;; Also bind `yas-minor-mode' to prevent fallback
+                ;; loops when other extensions use mechanisms similar
+                ;; to `yas--keybinding-beyond-yasnippet'. (github #525
+                ;; and #526)
+                ;; 
+                (yas-minor-mode nil)
+                (beyond-yasnippet (yas--keybinding-beyond-yasnippet)))

            (yas--message 4 "Falling back to %s"  beyond-yasnippet)
            (assert (or (null beyond-yasnippet) (commandp beyond-yasnippet)))
            (setq this-original-command beyond-yasnippet)
            (yas--message 4 "Falling back to %s"  beyond-yasnippet)
            (assert (or (null beyond-yasnippet) (commandp beyond-yasnippet)))
            (setq this-original-command beyond-yasnippet)


@@ -2234,18 +2239,21 @@ Common gateway for `yas-expand-from-trigger-key' and
         ((and (listp yas-fallback-behavior)
               (cdr yas-fallback-behavior)
               (eq 'apply (car yas-fallback-behavior)))
         ((and (listp yas-fallback-behavior)
               (cdr yas-fallback-behavior)
               (eq 'apply (car yas-fallback-behavior)))

-         (if (cddr yas-fallback-behavior)
-             (apply (cadr yas-fallback-behavior)
-                    (cddr yas-fallback-behavior))
-           (when (commandp (cadr yas-fallback-behavior))
-             (setq this-command (cadr yas-fallback-behavior))
-             (call-interactively (cadr yas-fallback-behavior)))))
+         (let ((command-or-fn (cadr yas-fallback-behavior))
+               (args (cddr yas-fallback-behavior))
+               (yas-fallback-behavior 'yas--fallback)
+               (yas-minor-mode nil))
+           (if args
+               (apply command-or-fn args)
+             (when (commandp command-or-fn)
+               (setq this-command command-or-fn)
+               (call-interactively command-or-fn)))))

         (t
          ;; also return nil if all the other fallbacks have failed
          nil)))
 
 (defun yas--keybinding-beyond-yasnippet ()
         (t
          ;; also return nil if all the other fallbacks have failed
          nil)))
 
 (defun yas--keybinding-beyond-yasnippet ()

-  "Return the ??"
+  "Get current keys's binding as if YASsnippet didn't exist."

   (let* ((yas-minor-mode nil)
          (yas--direct-keymaps nil)
          (keys (this-single-command-keys)))
   (let* ((yas-minor-mode nil)
          (yas--direct-keymaps nil)
          (keys (this-single-command-keys)))


@@ -2587,12 +2595,11 @@ and `kill-buffer' instead."
          (yas--current-template
           (and parsed
                (fboundp test-mode)
          (yas--current-template
           (and parsed
                (fboundp test-mode)

-               (yas--populate-template (yas--make-blank-template)
-                                      :table       nil ;; no tables for ephemeral snippets
-                                      :key         (first parsed)
-                                      :content     (second parsed)
-                                      :name        (third parsed)
-                                      :expand-env  (sixth parsed)))))
+               (yas--make-template :table       nil ;; no tables for ephemeral snippets
+                                   :key         (first parsed)
+                                   :content     (second parsed)
+                                   :name        (third parsed)
+                                   :expand-env  (sixth parsed)))))

     (cond (yas--current-template
            (let ((buffer-name (format "*testing snippet: %s*" (yas--template-name yas--current-template))))
              (kill-buffer (get-buffer-create buffer-name))
     (cond (yas--current-template
            (let ((buffer-name (format "*testing snippet: %s*" (yas--template-name yas--current-template))))
              (kill-buffer (get-buffer-create buffer-name))


@@ -2730,22 +2737,29 @@ and `kill-buffer' instead."
 ;;; User convenience functions, for using in `yas-key-syntaxes'
 
 (defun yas-try-key-from-whitespace (_start-point)
 ;;; User convenience functions, for using in `yas-key-syntaxes'
 
 (defun yas-try-key-from-whitespace (_start-point)

-  "Go back to nearest whitespace.
+  "As `yas-key-syntaxes' element, look for whitespace delimited key.

 
 A newline will be considered whitespace even if the mode syntax
 
 A newline will be considered whitespace even if the mode syntax

-marks it as something else (typically comment ender). Use as
-element of `yas-key-syntaxes'."
+marks it as something else (typically comment ender)."

   (skip-chars-backward "^[:space:]\n"))
 
 (defun yas-shortest-key-until-whitespace (_start-point)
   (skip-chars-backward "^[:space:]\n"))
 
 (defun yas-shortest-key-until-whitespace (_start-point)

-  "Return `again' until at whitespace.
+  "Like `yas-longest-key-from-whitespace' but take the shortest key."
+  (when (/= (skip-chars-backward "^[:space:]\n" (1- (point))) 0)
+    'again))
+
+(defun yas-longest-key-from-whitespace (start-point)
+  "As `yas-key-syntaxes' element, look for longest key between point and whitespace.

 
 A newline will be considered whitespace even if the mode syntax
 
 A newline will be considered whitespace even if the mode syntax

-marks it as something else (typically comment ender). Use as
-element of `yas-key-syntaxes'."
-  (when (/= (skip-chars-backward "^[:space:]\n" (1- (point))) 0)
+marks it as something else (typically comment ender)."
+  (if (= (point) start-point)
+      (yas-try-key-from-whitespace start-point)
+    (forward-char))
+  (unless (<= start-point (1+ (point)))

     'again))
 
     'again))
 

+

 \f
 ;;; User convenience functions, for using in snippet definitions
 
 \f
 ;;; User convenience functions, for using in snippet definitions
 


@@ -2987,12 +3001,14 @@ through the field's start point"
    ;; field must be zero length
    ;;
    (zerop (- (yas--field-start field) (yas--field-end field)))
    ;; field must be zero length
    ;;
    (zerop (- (yas--field-start field) (yas--field-end field)))

-   ;; skip if:
+   ;; field must have been modified
+   ;;
+   (yas--field-modified-p field)
+   ;; either:

    (or
    (or

-    ;;  1) is a nested field and it's been modified
+    ;;  1) it's a nested field

     ;;
     ;;

-    (and (yas--field-parent-field field)
-         (yas--field-modified-p field))
+    (yas--field-parent-field field)

     ;;  2) ends just before the snippet end
     ;;
     (and (eq field (car (last (yas--snippet-fields snippet))))
     ;;  2) ends just before the snippet end
     ;;
     (and (eq field (car (last (yas--snippet-fields snippet))))


@@ -3000,7 +3016,8 @@ through the field's start point"
    ;; the field numbered 0, just before the exit marker, should
    ;; never be skipped
    ;;
    ;; the field numbered 0, just before the exit marker, should
    ;; never be skipped
    ;;

-   (not (zerop (yas--field-number field)))))
+   (not (and (yas--field-number field)
+             (zerop (yas--field-number field))))))

 
 (defun yas--snippets-at-point (&optional all-snippets)
   "Return a sorted list of snippets at point.
 
 (defun yas--snippets-at-point (&optional all-snippets)
   "Return a sorted list of snippets at point.


@@ -3391,17 +3408,10 @@ progress."
 ;; snippet outside the active field. Actual protection happens in
 ;; `yas--on-protection-overlay-modification'.
 ;;
 ;; snippet outside the active field. Actual protection happens in
 ;; `yas--on-protection-overlay-modification'.
 ;;

-;; Currently this signals an error which inhibits the command. For
-;; commands that move point (like `kill-line'), point is restored in
-;; the `yas--post-command-handler' using a global
-;; `yas--protection-violation' variable.
-;;
-;; Alternatively, I've experimented with an implementation that
-;; commits the snippet before actually calling `this-command'
-;; interactively, and then signals an error, which is ignored. but
-;; blocks all other million modification hooks. This presented some
-;; problems with stacked expansion.
-;;
+;; As of github #537 this no longer inhibits the command by issuing an
+;; error: all the snippets at point, including nested snippets, are
+;; automatically commited and the current command can proceed.
+;; 

 (defun yas--make-move-field-protection-overlays (snippet field)
   "Place protection overlays surrounding SNIPPET's FIELD.
 
 (defun yas--make-move-field-protection-overlays (snippet field)
   "Place protection overlays surrounding SNIPPET's FIELD.
 


@@ -3434,23 +3444,17 @@ Move the overlays, or create them if they do not exit."
              ;; (overlay-put ov 'evaporate t)
              (overlay-put ov 'modification-hooks '(yas--on-protection-overlay-modification)))))))
 
              ;; (overlay-put ov 'evaporate t)
              (overlay-put ov 'modification-hooks '(yas--on-protection-overlay-modification)))))))
 

-(defvar yas--protection-violation nil
-  "When non-nil, signals attempts to erroneously exit or modify the snippet.
-
-Functions in the `post-command-hook', for example
-`yas--post-command-handler' can check it and reset its value to
-nil.  The variables value is the point where the violation
-originated")
-

 (defun yas--on-protection-overlay-modification (_overlay after? _beg _end &optional _length)
   "Signals a snippet violation, then issues error.
 
 The error should be ignored in `debug-ignored-errors'"
 (defun yas--on-protection-overlay-modification (_overlay after? _beg _end &optional _length)
   "Signals a snippet violation, then issues error.
 
 The error should be ignored in `debug-ignored-errors'"

-  (unless yas--inhibit-overlay-hooks
-    (cond ((not (or after?
-                    (yas--undo-in-progress)))
-           (setq yas--protection-violation (point))
-           (error "Exit the snippet first!")))))
+  (unless (or yas--inhibit-overlay-hooks
+              after?
+              (yas--undo-in-progress))
+    (let ((snippets (yas--snippets-at-point)))
+      (yas--message 3 "Comitting snippets. Action would destroy a protection overlay.")
+      (cl-loop for snippet in snippets
+               do (yas--commit-snippet snippet)))))

 
 (add-to-list 'debug-ignored-errors "^Exit the snippet first!$")
 
 
 (add-to-list 'debug-ignored-errors "^Exit the snippet first!$")
 


@@ -3484,8 +3488,12 @@ The error should be ignored in `debug-ignored-errors'"
   "Expand snippet CONTENT at current point.
 
 Text between START and END will be deleted before inserting
   "Expand snippet CONTENT at current point.
 
 Text between START and END will be deleted before inserting

-template.  EXPAND-ENV is are let-style variable to value bindings
+template.  EXPAND-ENV is a list of (SYM VALUE) let-style dynamic bindings

 considered when expanding the snippet."
 considered when expanding the snippet."

+  (cl-assert (and yas-minor-mode
+                  (memq 'yas--post-command-handler post-command-hook))
+             nil
+             "[yas] `yas-expand-snippet' needs properly setup `yas-minor-mode'")

   (run-hooks 'yas-before-expand-snippet-hook)
 
   ;;
   (run-hooks 'yas-before-expand-snippet-hook)
 
   ;;


@@ -3922,7 +3930,7 @@ Meant to be called in a narrowed buffer, does various passes"
         (n (line-beginning-position)))
     (while (or (eql c ?\ )
                (eql c ?\t))
         (n (line-beginning-position)))
     (while (or (eql c ?\ )
                (eql c ?\t))

-      (incf n)
+      (cl-incf n)

       (setq c (char-after n)))
     n))
 
       (setq c (char-after n)))
     n))
 


@@ -4249,10 +4257,7 @@ When multiple expressions are found, only the last one counts."
 ;;
 (defun yas--post-command-handler ()
   "Handles various yasnippet conditions after each command."
 ;;
 (defun yas--post-command-handler ()
   "Handles various yasnippet conditions after each command."

-  (cond (yas--protection-violation
-         (goto-char yas--protection-violation)
-         (setq yas--protection-violation nil))
-        ((eq 'undo this-command)
+  (cond ((eq 'undo this-command)

          ;;
          ;; After undo revival the correct field is sometimes not
          ;; restored correctly, this condition handles that
          ;;
          ;; After undo revival the correct field is sometimes not
          ;; restored correctly, this condition handles that


@@ -4287,7 +4292,7 @@ When multiple expressions are found, only the last one counts."
                    (or (and fallback
                             (format "call command `%s'."
                                     (pp-to-string fallback)))
                    (or (and fallback
                             (format "call command `%s'."
                                     (pp-to-string fallback)))

-                       "do nothing (`yas-expand' doesn't shadow\nanything).")))
+                       "do nothing (`yas-expand' doesn't override\nanything).")))

                 ((eq yas-fallback-behavior 'return-nil)
                  "do nothing.")
                 (t "defer to `yas-fallback-behavior' (which see)."))))
                 ((eq yas-fallback-behavior 'return-nil)
                  "do nothing.")
                 (t "defer to `yas-fallback-behavior' (which see)."))))


@@ -4359,6 +4364,11 @@ object satisfying `yas--field-p' to restrict the expansion to.")))
   (when (> yas-verbosity level)
     (message "%s" (apply #'yas--format message args))))
 
   (when (> yas-verbosity level)
     (message "%s" (apply #'yas--format message args))))
 

+(defun yas--warning (format-control &rest format-args)
+  (let ((msg (apply #'format format-control format-args)))
+    (display-warning 'yasnippet msg :warning)
+    (yas--message 1 msg)))
+

 (defun yas--format (format-control &rest format-args)
   (apply #'format (concat "[yas] " format-control) format-args))
 
 (defun yas--format (format-control &rest format-args)
   (apply #'format (concat "[yas] " format-control) format-args))
 


@@ -4422,6 +4432,11 @@ and return the directory.  Return nil if not found."
 \f
 ;;; Backward compatibility to yasnippet <= 0.7
 
 \f
 ;;; Backward compatibility to yasnippet <= 0.7
 

+(defun yas-initialize ()
+  "For backward compatibility, enable `yas-minor-mode' globally."
+  (declare (obsolete "Use (yas-global-mode 1) instead." "0.8"))
+  (yas-global-mode 1))
+

 (defvar yas--backported-syms '(;; `defcustom's
                              ;;
                              yas-snippet-dirs
 (defvar yas--backported-syms '(;; `defcustom's
                              ;;
                              yas-snippet-dirs


@@ -4487,6 +4502,7 @@ and return the directory.  Return nil if not found."
                              yas-exit-snippet
                              yas-exit-all-snippets
                              yas-skip-and-clear-or-delete-char
                              yas-exit-snippet
                              yas-exit-all-snippets
                              yas-skip-and-clear-or-delete-char

+                             yas-initialize

 
                              ;; symbols that I "exported" for use
                              ;; in snippets and hookage
 
                              ;; symbols that I "exported" for use
                              ;; in snippets and hookage


@@ -4558,9 +4574,9 @@ can more or less safely rely upon them.")
 
 \f
 (provide 'yasnippet)
 
 \f
 (provide 'yasnippet)

-
-;;; yasnippet.el ends here

 ;; Local Variables:
 ;; coding: utf-8
 ;; Local Variables:
 ;; coding: utf-8

+;; indent-tabs-mode: nil

 ;; byte-compile-warnings: (not cl-functions)
 ;; End:
 ;; byte-compile-warnings: (not cl-functions)
 ;; End:

+;;; yasnippet.el ends here