mirror of
https://github.com/joaotavora/yasnippet.git
synced 2025-10-14 05:23:04 +00:00
547 lines
21 KiB
EmacsLisp
547 lines
21 KiB
EmacsLisp
;;; snippet.el --- yasnippet's 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:
|
||
|
||
(require 'cl-lib)
|
||
|
||
|
||
;;; the define-snippet macro and its helpers
|
||
;;;
|
||
(defun snippet--form-make-field-sym (field-name &optional parent-field-sym)
|
||
(make-symbol (format "field-%s%s" field-name
|
||
(if parent-field-sym
|
||
(format "-son-of-%s" parent-field-sym)
|
||
""))))
|
||
(defun snippet--form-make-mirror-sym (mirror-name source-field-name
|
||
&optional parent-field-sym)
|
||
(make-symbol (format "mirror-%s-of-%s%s" mirror-name source-field-name
|
||
(if parent-field-sym
|
||
(format "-son-of-%s" parent-field-sym)
|
||
""))))
|
||
|
||
(defvar snippet--marker-sym-obarray (make-vector 100 nil))
|
||
|
||
(defun snippet--start-marker-name (sym)
|
||
(intern (format "%s-beg" sym) snippet--marker-sym-obarray))
|
||
|
||
(defun snippet--end-marker-name (sym)
|
||
(intern (format "%s-end" sym) snippet--marker-sym-obarray))
|
||
|
||
(defvar snippet--form-mirror-sym-idx nil)
|
||
|
||
(defun snippet--function-p (form)
|
||
(or (functionp form)
|
||
(and (eq 'function (car form))
|
||
(fboundp (cl-second form)))
|
||
(and (eq 'quote (car form))
|
||
(fboundp (cl-second form)))))
|
||
|
||
(defun snippet--form-sym-tuples (forms &optional parent-field-sym)
|
||
"Produce information for composing the snippet expansion function.
|
||
|
||
A tuple of 6 elements is created for each form in FORMS.
|
||
|
||
\(SYM FORM PARENT-FIELD-SYM ADJACENT-PREV-SYM PREV-FORM NEXT-FORM)
|
||
|
||
Forms representing fields with nested elements are recursively
|
||
iterated depth-first, resulting in a flattened list."
|
||
(cl-loop unless forms return nil
|
||
with snippet--form-mirror-sym-idx = (or snippet--form-mirror-sym-idx
|
||
0)
|
||
with adjacent-prev-sym
|
||
|
||
for (prev-form form next-form) on `(nil ,@forms)
|
||
|
||
for (sym childrenp) = (pcase form
|
||
(`(field ,name . ,rest)
|
||
(list (snippet--form-make-field-sym
|
||
name
|
||
parent-field-sym)
|
||
(listp (car rest))))
|
||
(`(mirror ,name . ,_)
|
||
(incf snippet--form-mirror-sym-idx)
|
||
(list (snippet--form-make-mirror-sym
|
||
snippet--form-mirror-sym-idx
|
||
name
|
||
parent-field-sym))))
|
||
|
||
append (cond (sym
|
||
`((,sym
|
||
,form
|
||
,parent-field-sym
|
||
,adjacent-prev-sym
|
||
,prev-form
|
||
,next-form)
|
||
,@(when childrenp
|
||
(snippet--form-sym-tuples (third form) sym))))
|
||
((null form) nil)
|
||
((or (stringp form)
|
||
(snippet--function-p form))
|
||
`((string-or-function ,form ,parent-field-sym)))
|
||
(t
|
||
(error "unknown type of snippet form %s" form)))
|
||
do (setq adjacent-prev-sym sym)))
|
||
|
||
(defun snippet--make-marker-init-forms (tuples)
|
||
"Make marker init forms for the snippet objects in TUPLES.
|
||
|
||
Imagine this snippet:
|
||
|
||
ff1 sss mm1 ff2 mm5
|
||
|
|
||
ff3 sss mm4
|
||
|
||
I would need these somewhere in the let* form
|
||
|
||
((ff1-beg (make-marker))
|
||
(ff1-end (make-marker))
|
||
(mm1-beg (make-marker))
|
||
(mm1-end (make-marker))
|
||
(ff2-beg mm1-end)
|
||
(ff2-end (make-marker))
|
||
(ff3-beg ff2-end)
|
||
(ff3-end (make-marker))
|
||
(mm4-beg (make-marker))
|
||
(mm4-end ff2-end)
|
||
(mm5-beg ff2-end)
|
||
(mm5-end (make-marker)))
|
||
"
|
||
(cl-loop for (sym nil parent-sym adjacent-prev-sym prev next) in tuples
|
||
unless (eq sym 'string-or-function)
|
||
append `((,(snippet--start-marker-name sym)
|
||
,(or (and adjacent-prev-sym
|
||
(snippet--end-marker-name adjacent-prev-sym))
|
||
(and parent-sym
|
||
(not prev)
|
||
(snippet--start-marker-name parent-sym))
|
||
`(snippet--make-marker)))
|
||
(,(snippet--end-marker-name sym)
|
||
,(or (and parent-sym
|
||
(not next)
|
||
(snippet--end-marker-name parent-sym))
|
||
`(snippet--make-marker))))))
|
||
|
||
|
||
(defun snippet--first-field-sym (tuples)
|
||
(car (car (snippet--field-tuples tuples))))
|
||
|
||
(defun snippet--field-tuples (tuples)
|
||
(cl-remove-if-not #'(lambda (form)
|
||
(and (consp form)
|
||
(eq 'field (car form))))
|
||
tuples :key #'cadr))
|
||
|
||
(defun snippet--init-field-and-mirror-forms (tuples)
|
||
(let* ((field-mirrors (make-hash-table))
|
||
;; we first collect `snippet--make-mirror' forms. When
|
||
;; collecting them, we populate the `field-mirrors' table...
|
||
;;
|
||
(tuples (cl-remove 'string-or-function tuples :key #'car))
|
||
(make-mirror-forms
|
||
(cl-loop for ((prev-sym)
|
||
(sym (type name transform) parent-sym)
|
||
(next-sym))
|
||
on `(nil ,@tuples)
|
||
when (and sym (eq 'mirror type))
|
||
collect (let ((source-sym nil))
|
||
(cl-loop for (sym-b (type-b name-b)) in tuples
|
||
when (and
|
||
(eq 'field type-b)
|
||
(eq name name-b))
|
||
do
|
||
(setq source-sym sym-b)
|
||
(puthash source-sym
|
||
(cons sym (gethash source-sym
|
||
field-mirrors))
|
||
field-mirrors))
|
||
(unless source-sym
|
||
(error "mirror mentions unknown field %s"
|
||
name))
|
||
`((,sym (snippet--make-mirror))
|
||
(snippet--init-mirror
|
||
,sym
|
||
,(snippet--start-marker-name sym)
|
||
,(snippet--end-marker-name sym)
|
||
,parent-sym
|
||
,prev-sym
|
||
,next-sym
|
||
,source-sym
|
||
,(snippet--transform-lambda transform))))))
|
||
;; so that we can now create `snippet--make-field' forms with
|
||
;; complete lists of mirror symbols.
|
||
;;
|
||
(make-field-forms
|
||
(cl-loop for ((prev-sym)
|
||
(sym (type name _value) parent-sym)
|
||
(next-sym))
|
||
on `(nil ,@tuples)
|
||
when (and sym (eq 'field type))
|
||
collect `((,sym (snippet--make-field))
|
||
(snippet--init-field
|
||
,sym
|
||
,(snippet--start-marker-name sym)
|
||
,(snippet--end-marker-name sym)
|
||
,parent-sym
|
||
,prev-sym
|
||
,next-sym
|
||
,name
|
||
(list
|
||
,@(reverse
|
||
(gethash sym field-mirrors))))))))
|
||
|
||
(append make-field-forms
|
||
make-mirror-forms)))
|
||
|
||
(defun snippet--transform-lambda (transform-form)
|
||
`(lambda (field-text)
|
||
,(or transform-form
|
||
'field-text)))
|
||
|
||
(defun define--snippet-body (body)
|
||
"Does the actual work for `define-snippet'"
|
||
(let* ((sym-tuples (snippet--form-sym-tuples body))
|
||
(marker-init-forms (snippet--make-marker-init-forms sym-tuples))
|
||
(init-object-forms (snippet--init-field-and-mirror-forms sym-tuples))
|
||
(first-field-sym (snippet--first-field-sym sym-tuples)))
|
||
`(let* (,@(mapcar #'car init-object-forms)
|
||
,@marker-init-forms)
|
||
|
||
,@(mapcar #'second init-object-forms)
|
||
|
||
,@(cl-loop
|
||
for (sym form) in sym-tuples
|
||
collect (pcase form
|
||
(`(field ,_ ,text)
|
||
`(snippet--insert-field ,sym ,(if (stringp text)
|
||
text)))
|
||
(`(mirror . ,_)
|
||
`(snippet--insert-mirror ,sym))
|
||
((pred stringp)
|
||
`(insert ,form))
|
||
((pred functionp)
|
||
`(insert (funcall ,form)))))
|
||
|
||
(setq snippet--field-overlay
|
||
(make-overlay (point) (point) nil nil t))
|
||
(overlay-put snippet--field-overlay
|
||
'face
|
||
'snippet-field-face)
|
||
(overlay-put snippet--field-overlay
|
||
'modification-hooks
|
||
'(snippet--field-overlay-changed))
|
||
(overlay-put snippet--field-overlay
|
||
'insert-in-front-hooks
|
||
'(snippet--field-overlay-changed))
|
||
(overlay-put snippet--field-overlay
|
||
'insert-behind-hooks
|
||
'(snippet--field-overlay-changed))
|
||
(overlay-put snippet--field-overlay
|
||
'keymap
|
||
snippet-field-keymap)
|
||
(overlay-put snippet--field-overlay
|
||
'snippet--objects
|
||
(list ,@(remove 'string-or-function
|
||
(mapcar #'car
|
||
sym-tuples))))
|
||
,(if first-field-sym
|
||
`(snippet--move-to-field ,first-field-sym))
|
||
(add-hook 'post-command-hook 'snippet--post-command-hook t t))))
|
||
|
||
|
||
(cl-defmacro define-snippet (name () &rest body)
|
||
"Define NAME as a snippet-inserting function.
|
||
|
||
NAME's function definition is set to a function with no arguments
|
||
that inserts the fields components at point.
|
||
|
||
Each form in BODY can be:
|
||
|
||
* A cons (field FIELD-NAME FIELD-VALUE FIELD-TRANSFORM)
|
||
definining a snippet field. A snippet field can be navigated to
|
||
using `snippet-next-field' and
|
||
`snippet-prev-field'. FIELD-TRANSFORM is currently
|
||
unimplemented.
|
||
|
||
* A cons (mirror FIELD-NAME MIRROR-TRANSFORM) defining a mirror
|
||
of the field named FIELD-NAME. Each time the text under the
|
||
field changes, the form MIRROR-TRANSFORM is invoked with the
|
||
variable `field-text' set to the text under the field. The
|
||
string produced become the text under the mirror.
|
||
|
||
* A string literal which is inserted as a literal part of the
|
||
snippet and remains unchanged while the snippet is navigated.
|
||
|
||
* A symbol designating a function which is called when the
|
||
snippet is inserted. The string produced is treated as a
|
||
literal string.
|
||
|
||
* A lambda form taking no arguments, called when the snippet is
|
||
inserted. Again, the string produced is treated as a literal
|
||
snippet string.
|
||
|
||
ARGS is an even-numbered property list of (KEY VAL) pairs. KEY
|
||
can be:
|
||
|
||
* the symbol `:obarray', in which case the symbol NAME in
|
||
interned in the obarray VAL instead of the global obarray. This
|
||
options is currently unimplemented."
|
||
(declare (debug (&define name sexp &rest &or
|
||
;; curiously, function-form doesn't work here
|
||
;;
|
||
("mirror" sexp def-form)
|
||
("lambda" sexp def-form)
|
||
("field" sexp &rest sexp)
|
||
sexp)))
|
||
`(defun ,name ()
|
||
,(define--snippet-body body)))
|
||
|
||
(cl-defmacro make-snippet (forms)
|
||
"Same as `define-snippet', but return an anonymous function."
|
||
`(lambda () ,(define--snippet-body forms)))
|
||
|
||
|
||
;;; Snippet mechanics
|
||
;;;
|
||
|
||
(cl-defstruct snippet--object
|
||
start end parent-field next prev (buffer (current-buffer)))
|
||
|
||
(defun snippet--init-object (object start end parent-field prev next)
|
||
(setf (snippet--object-start object) start
|
||
(snippet--object-end object) end
|
||
(snippet--object-parent-field object) parent-field
|
||
(snippet--object-next object) next
|
||
(snippet--object-prev object) prev))
|
||
|
||
(cl-defstruct (snippet--field (:constructor snippet--make-field ())
|
||
(:include snippet--object)
|
||
(:print-function snippet--describe-field))
|
||
name
|
||
(mirrors '()))
|
||
|
||
(defun snippet--describe-field (field)
|
||
(with-current-buffer (snippet--object-buffer field)
|
||
(format "field %s from %s to %s covering \"%s\""
|
||
(snippet--field-name field)
|
||
(marker-position (snippet--object-start field))
|
||
(marker-position (snippet--object-end field))
|
||
(buffer-substring-no-properties
|
||
(snippet--object-start field)
|
||
(snippet--object-end field)))))
|
||
|
||
(defun snippet--init-field (object start end parent-field prev next
|
||
name mirrors)
|
||
(snippet--init-object object start end parent-field prev next)
|
||
(setf (snippet--field-name object) name
|
||
(snippet--field-mirrors object) mirrors))
|
||
|
||
(cl-defstruct (snippet--mirror (:constructor snippet--make-mirror ())
|
||
(:include snippet--object)
|
||
(:print-function snippet--describe-mirror))
|
||
source
|
||
(transform nil))
|
||
|
||
(defun snippet--init-mirror (object start end parent-field prev next
|
||
source transform)
|
||
(snippet--init-object object start end parent-field prev next)
|
||
(setf (snippet--mirror-source object) source
|
||
(snippet--mirror-transform object) transform))
|
||
|
||
(defun snippet--describe-mirror (mirror)
|
||
(with-current-buffer (snippet--object-buffer mirror)
|
||
(format "mirror from %s to %s covering \"%s\""
|
||
(marker-position (snippet--object-start mirror))
|
||
(marker-position (snippet--object-end mirror))
|
||
(buffer-substring-no-properties
|
||
(snippet--object-start mirror)
|
||
(snippet--object-end mirror)))))
|
||
|
||
(defgroup snippet nil
|
||
"Customize snippet features"
|
||
:group 'convenience)
|
||
|
||
(defface snippet-field-face
|
||
'((t (:inherit 'region)))
|
||
"Face used to highlight the currently active field of a snippet")
|
||
|
||
(defvar snippet-field-keymap
|
||
(let ((map (make-sparse-keymap)))
|
||
(define-key map (kbd "<tab>") 'snippet-next-field)
|
||
(define-key map (kbd "S-<tab>") 'snippet-prev-field)
|
||
map)
|
||
"The active keymap while a snippet expansion is in progress.")
|
||
|
||
(defvar snippet--field-overlay nil)
|
||
|
||
(defun snippet--object-next-field (object)
|
||
(loop for next = (snippet--object-next object)
|
||
then (snippet--object-next next)
|
||
when (snippet--field-p next)
|
||
return next))
|
||
|
||
(defun snippet--object-prev-field (object)
|
||
(loop for prev = (snippet--object-prev object)
|
||
then (snippet--object-prev prev)
|
||
when (snippet--field-p prev)
|
||
return prev))
|
||
|
||
(defun snippet-next-field (&optional prev)
|
||
(interactive)
|
||
(let* ((field (overlay-get snippet--field-overlay 'snippet--field))
|
||
(target (if prev
|
||
(snippet--object-prev-field field)
|
||
(snippet--object-next-field field))))
|
||
(if target
|
||
(snippet--move-to-field target)
|
||
(unless prev
|
||
(goto-char (snippet--object-end field)))
|
||
(snippet-exit-snippet))))
|
||
|
||
(defun snippet-prev-field ()
|
||
(interactive)
|
||
(snippet-next-field t))
|
||
|
||
(defun snippet-exit-snippet (&optional reason)
|
||
(delete-overlay snippet--field-overlay)
|
||
(message "snippet exited%s"
|
||
(or (and reason
|
||
(format " (%s)" reason))
|
||
"")))
|
||
|
||
(defun snippet--make-marker ()
|
||
(let ((marker (make-marker)))
|
||
(set-marker-insertion-type marker t)
|
||
(set-marker marker (point))))
|
||
|
||
(defun snippet--open-markers (object)
|
||
(set-marker-insertion-type (snippet--object-start object) nil)
|
||
(set-marker-insertion-type (snippet--object-end object) t))
|
||
|
||
(defun snippet--close-markers (object)
|
||
(let ((start (snippet--object-start object))
|
||
(end (snippet--object-end object)))
|
||
(cond ((= start end)
|
||
(set-marker-insertion-type start t)
|
||
(set-marker-insertion-type end t))
|
||
(t
|
||
(set-marker-insertion-type start t)
|
||
(set-marker-insertion-type end nil)))))
|
||
|
||
(defun snippet--call-with-current-object (object fn)
|
||
(unwind-protect
|
||
(progn
|
||
(snippet--open-markers object)
|
||
(funcall fn))
|
||
(snippet--close-markers object)))
|
||
|
||
(defmacro snippet--with-current-object (object &rest body)
|
||
(declare (indent defun) (debug t))
|
||
`(snippet--call-with-current-object ,object #'(lambda () ,@body)))
|
||
|
||
|
||
(defun snippet--insert-field (field text)
|
||
(when text
|
||
(snippet--with-current-object field
|
||
(insert text))))
|
||
|
||
(defun snippet--insert-mirror (mirror)
|
||
(snippet--update-mirror mirror))
|
||
|
||
(defun snippet--update-mirror (mirror)
|
||
(snippet--with-current-object mirror
|
||
(delete-region (snippet--object-start mirror)
|
||
(snippet--object-end mirror))
|
||
(save-excursion
|
||
(goto-char (snippet--object-start mirror))
|
||
(insert (funcall (snippet--mirror-transform mirror)
|
||
(snippet--field-text (snippet--mirror-source mirror)))))))
|
||
|
||
(defun snippet--move-to-field (field)
|
||
(goto-char (snippet--object-start field))
|
||
(move-overlay snippet--field-overlay
|
||
(point)
|
||
(snippet--object-end field))
|
||
(overlay-put snippet--field-overlay 'snippet--field field))
|
||
|
||
(defun snippet--field-overlay-changed (overlay after? _beg _end &optional _length)
|
||
(let* ((field (overlay-get overlay 'snippet--field))
|
||
(inhibit-modification-hooks t))
|
||
(cond (after?
|
||
(snippet--close-markers field)
|
||
(mapc #'snippet--update-mirror (snippet--field-mirrors field))
|
||
(move-overlay overlay
|
||
(snippet--object-start field)
|
||
(snippet--object-end field)))
|
||
(t
|
||
(snippet--open-markers field)))))
|
||
|
||
(defun snippet--field-text (field)
|
||
(buffer-substring-no-properties (snippet--object-start field)
|
||
(snippet--object-end field)))
|
||
|
||
(defvar snippet--debug nil)
|
||
;; (setq snippet--debug t)
|
||
|
||
(defun snippet--post-command-hook ()
|
||
(cond ((and snippet--field-overlay
|
||
(overlay-buffer snippet--field-overlay))
|
||
(cond ((or (< (point)
|
||
(overlay-start snippet--field-overlay))
|
||
(> (point)
|
||
(overlay-end snippet--field-overlay)))
|
||
(snippet-exit-snippet "point left snippet")
|
||
(remove-hook 'post-command-hook 'snippet--post-command-hook t))
|
||
(snippet--debug
|
||
(snippet--debug-snippet snippet--field-overlay))))
|
||
(snippet--field-overlay
|
||
;; snippet must have been exited for some other reason
|
||
;;
|
||
(remove-hook 'post-command-hook 'snippet--post-command-hook t))))
|
||
|
||
(defun snippet--debug-snippet (field-overlay)
|
||
(with-current-buffer (get-buffer-create "*snippet-debug*")
|
||
(let ((inhibit-read-only t))
|
||
(erase-buffer)
|
||
(let ((active-field (overlay-get field-overlay 'snippet--field)))
|
||
(cl-loop for object in (overlay-get field-overlay 'snippet--objects)
|
||
when (snippet--field-p object)
|
||
do
|
||
(insert (snippet--describe-field object))
|
||
(when (eq object active-field) (insert " (active)"))
|
||
(insert "\n")
|
||
(cl-loop for mirror in (snippet--field-mirrors object)
|
||
do (insert " " (snippet--describe-mirror mirror)
|
||
"\n")))))
|
||
(display-buffer (current-buffer))))
|
||
|
||
(provide 'snippet)
|
||
|
||
;; Local Variables:
|
||
;; coding: utf-8
|
||
;; whitespace-style: (face lines-tail)
|
||
;; whitespace-line-column: 80
|
||
;; fill-column: 80
|
||
;; End:
|
||
;; snippet.el ends here
|