1 ;;; geiser-syntax.el -- utilities for parsing scheme syntax
3 ;; Copyright (C) 2009, 2010 Jose Antonio Ortega Ruiz
5 ;; This program is free software; you can redistribute it and/or
6 ;; modify it under the terms of the Modified BSD License. You should
7 ;; have received a copy of the license along with this program. If
8 ;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.
10 ;; Start date: Sun Feb 08, 2009 15:03
14 (require 'geiser-impl
)
15 (require 'geiser-popup
)
16 (require 'geiser-base
)
20 (eval-when-compile (require 'cl
))
25 (defmacro geiser-syntax--scheme-indent
(&rest pairs
)
26 `(progn ,@(mapcar (lambda (p)
27 `(put ',(car p
) 'scheme-indent-function
',(cadr p
)))
30 (geiser-syntax--scheme-indent
64 (parameterize-break 1)
88 ;;; Extra syntax keywords
89 (defconst geiser-syntax--keywords
90 '(("\\[\\(else\\)\\>" .
1)
91 ("(\\(parameterize\\)\\>" .
1)))
93 (font-lock-add-keywords 'scheme-mode geiser-syntax--keywords
)
95 (geiser-impl--define-caller geiser-syntax--impl-kws keywords
()
96 "A variable (or thunk returning a value) giving additional,
97 implementation-specific entries for font-lock-keywords.")
99 (defun geiser-syntax--add-kws ()
100 (let ((kw (geiser-syntax--impl-kws geiser-impl--implementation
)))
101 (when kw
(font-lock-add-keywords nil kw
))))
104 ;;; A simple scheme reader
106 (defvar geiser-syntax--read
/buffer-limit nil
)
108 (defsubst geiser-syntax--read
/eos
()
110 (and geiser-syntax--read
/buffer-limit
111 (<= geiser-syntax--read
/buffer-limit
(point)))))
113 (defsubst geiser-syntax--read
/next-char
()
114 (unless (geiser-syntax--read/eos
)
118 (defsubst geiser-syntax--read
/token
(token)
119 (geiser-syntax--read/next-char
)
120 (if (listp token
) token
(list token
)))
122 (defsubst geiser-syntax--read
/elisp
()
123 (ignore-errors (read (current-buffer))))
125 (defun geiser-syntax--read/matching
(open close
)
128 (while (and (> count
0)
129 (geiser-syntax--read/next-char
))
130 (cond ((looking-at-p open
) (setq count
(1+ count
)))
131 ((looking-at-p close
) (setq count
(1- count
)))))
132 (buffer-substring-no-properties p
(point))))
134 (defsubst geiser-syntax--read
/unprintable
()
135 (geiser-syntax--read/token
136 (cons 'unprintable
(geiser-syntax--read/matching
"<" ">"))))
138 (defun geiser-syntax--read/skip-comment
()
139 (while (and (geiser-syntax--read/next-char
)
140 (nth 8 (syntax-ppss))))
141 (geiser-syntax--read/next-token
))
143 (defun geiser-syntax--read/next-token
()
144 (skip-syntax-forward "->")
145 (if (geiser-syntax--read/eos
) '(eob)
147 (?\
; (geiser-syntax--read/skip-comment))
148 ((?\
( ?\
[) (geiser-syntax--read/token
'lparen
))
149 ((?\
) ?\
]) (geiser-syntax--read/token
'rparen
))
150 (?.
(if (memq (car (syntax-after (1+ (point)))) '(0 11 12))
151 (geiser-syntax--read/token
'dot
)
152 (cons 'atom
(geiser-syntax--read/elisp
))))
153 (?\
# (case (geiser-syntax--read/next-char
)
155 (?|
(geiser-syntax--read/skip-comment
))
156 (?
: (if (geiser-syntax--read/next-char
)
157 (cons 'kwd
(geiser-syntax--read/elisp
))
159 (?
\\ (cons 'char
(geiser-syntax--read/elisp
)))
160 (?\
( (geiser-syntax--read/token
'vectorb
))
161 (?\
< (geiser-syntax--read/unprintable
))
162 ((?
' ?
` ?
,) (geiser-syntax--read/next-token
))
163 (t (let ((tok (geiser-syntax--read/elisp
)))
164 (if tok
(cons 'atom
(intern (format "#%s" tok
)))
165 (geiser-syntax--read/next-token
))))))
166 (?
\' (geiser-syntax--read/token
'(quote . quote
)))
167 (?\
` (geiser-syntax--read/token
168 `(backquote .
,backquote-backquote-symbol
)))
169 (?
, (if (eq (geiser-syntax--read/next-char
) ?
@)
170 (geiser-syntax--read/token
171 `(splice .
,backquote-splice-symbol
))
172 `(unquote .
,backquote-unquote-symbol
)))
173 (?
\" (cons 'string
(geiser-syntax--read/elisp
)))
174 (t (cons 'atom
(geiser-syntax--read/elisp
))))))
176 (defsubst geiser-syntax--read
/match
(&rest tks
)
177 (let ((token (geiser-syntax--read/next-token
)))
178 (if (memq (car token
) tks
) token
179 (error "Unexpected token: %s" token
))))
181 (defsubst geiser-syntax--read
/skip-until
(&rest tks
)
183 (while (and (not (memq (car token
) tks
))
184 (not (eq (car token
) 'eob
)))
185 (setq token
(geiser-syntax--read/next-token
)))
188 (defsubst geiser-syntax--read
/try
(&rest tks
)
190 (tk (ignore-errors (apply 'geiser-syntax--read
/match tks
))))
191 (unless tk
(goto-char p
))
194 (defun geiser-syntax--read/list
()
195 (cond ((geiser-syntax--read/try
'dot
)
196 (let ((tail (geiser-syntax--read)))
197 (geiser-syntax--read/skip-until
'eob
'rparen
)
199 ((geiser-syntax--read/try
'rparen
'eob
) nil
)
200 (t (cons (geiser-syntax--read)
201 (geiser-syntax--read/list
)))))
203 (defun geiser-syntax--read ()
204 (let ((token (geiser-syntax--read/next-token
))
205 (max-lisp-eval-depth (max max-lisp-eval-depth
3000)))
208 (lparen (geiser-syntax--read/list
))
209 (vectorb (apply 'vector
(geiser-syntax--read/list
)))
210 ((quote backquote unquote splice
) (list (cdr token
)
211 (geiser-syntax--read)))
212 (kwd (intern (format ":%s" (cdr token
))))
213 (unprintable (format "#<%s>" (cdr token
)))
214 ((char string atom
) (cdr token
))
215 (t (error "Reading scheme syntax: unexpected token: %s" token
)))))
217 (defun geiser-syntax--read-from-string (string &optional start end
)
218 (when (stringp string
)
219 (let* ((start (or start
0))
220 (end (or end
(length string
)))
221 (max-lisp-eval-depth (max max-lisp-eval-depth
(- end start
))))
223 (save-excursion (insert string
))
224 (cons (ignore-errors (geiser-syntax--read)) (point))))))
226 (defsubst geiser-syntax--form-after-point
(&optional boundary
)
227 (let ((geiser-syntax--read/buffer-limit
(and (numberp boundary
) boundary
)))
228 (save-excursion (values (geiser-syntax--read) (point)))))
233 (defsubst geiser-syntax--symbol-at-point
()
234 (and (not (nth 8 (syntax-ppss)))
235 (let ((s (symbol-at-point)))
236 (and (not (eq s
'.
)) s
))))
238 (defsubst geiser-syntax--skip-comment
/string
()
239 (let ((pos (nth 8 (syntax-ppss))))
240 (goto-char (or pos
(point)))
243 (defsubst geiser-syntax--nesting-level
()
244 (or (nth 0 (syntax-ppss)) 0))
246 (defsubst geiser-syntax--pair-length
(p)
247 (if (cdr (last p
)) (1+ (safe-length p
)) (length p
)))
249 (defun geiser-syntax--shallow-form (boundary)
250 (when (looking-at-p "\\s(")
255 (while (< (point) boundary
)
256 (skip-syntax-forward "-<>")
257 (when (<= (point) boundary
)
259 (let ((s (symbol-at-point)))
260 (when (not (eq s
'.
)) (push (symbol-at-point) elems
))))))
263 (defun geiser-syntax--scan-sexps (&optional begin
)
264 (let* ((fst (geiser-syntax--symbol-at-point))
265 (smth (or fst
(not (looking-at-p "[\s \s)\s>\s<\n]"))))
266 (path (and fst
`((,fst
0)))))
268 (while (not (zerop (geiser-syntax--nesting-level)))
269 (let ((boundary (point)))
270 (geiser-syntax--skip-comment/string
)
272 (let ((form (geiser-syntax--shallow-form boundary
)))
273 (when (and (listp form
) (car form
) (symbolp (car form
)))
274 (let* ((len (geiser-syntax--pair-length form
))
275 (pos (if smth
(1- len
) (progn (setq smth t
) len
)))
276 (prev (and (> pos
1) (nth (1- pos
) form
)))
277 (prev (and (keywordp prev
) (list prev
))))
278 (push `(,(car form
) ,pos
,@prev
) path
)))))))
281 (defsubst geiser-syntax--binding-form-p
(bfs sbfs f
)
282 (or (memq f
'(define define
* define-syntax define-syntax-rule
283 lambda let let
* letrec parameterize
))
287 (defsubst geiser-syntax--binding-form
*-p
(sbfs f
)
288 (or (eq 'let
* f
) (memq f sbfs
)))
290 (defsubst geiser-syntax--if-symbol
(x) (and (symbolp x
) x
))
291 (defsubst geiser-syntax--if-list
(x) (and (listp x
) x
))
292 (defsubst geiser-syntax--normalize
(vars)
293 (mapcar (lambda (i) (if (listp i
) (car i
) i
)) vars
))
295 (defun geiser-syntax--linearize (form)
296 (cond ((not (listp form
)) (list form
))
298 (t (cons (car form
) (geiser-syntax--linearize (cdr form
))))))
300 (defun geiser-syntax--scan-locals (bfs sbfs form partial locals
)
301 (if (or (null form
) (not (listp form
)))
302 (geiser-syntax--normalize locals
)
303 (if (not (geiser-syntax--binding-form-p bfs sbfs
(car form
)))
304 (geiser-syntax--scan-locals bfs sbfs
305 (car (last form
)) partial locals
)
306 (let* ((head (car form
))
307 (name (geiser-syntax--if-symbol (cadr form
)))
308 (names (if name
(geiser-syntax--if-list (caddr form
))
309 (geiser-syntax--if-list (cadr form
))))
310 (rest (if name
(cdddr form
) (cddr form
)))
313 (geiser-syntax--binding-form*-p sbfs
315 (when name
(push name locals
))
317 (dolist (n (geiser-syntax--linearize names
))
319 (dolist (f (butlast rest
))
320 (when (and (listp f
) (eq (car f
) 'define
))
321 (push (cadr f
) locals
)))
322 (geiser-syntax--scan-locals bfs sbfs
323 (car (last (or rest names
)))
327 (defun geiser-syntax--locals-around-point (bfs sbfs
)
328 (when (eq major-mode
'scheme-mode
)
330 (let* ((sym (unless (geiser-syntax--skip-comment/string
)
333 (while (not (zerop (geiser-syntax--nesting-level)))
335 (multiple-value-bind (form end
)
336 (geiser-syntax--form-after-point boundary
)
338 (geiser-syntax--scan-locals bfs sbfs form
339 (> end boundary
) '())))))))
342 ;;; Fontify strings as Scheme code:
344 (defun geiser-syntax--font-lock-buffer ()
345 (let ((name " *geiser font lock*"))
346 (or (get-buffer name
)
347 (let ((buffer (get-buffer-create name
)))
349 (let ((geiser-default-implementation
350 (or geiser-default-implementation
351 (car geiser-active-implementations
))))
355 (defun geiser-syntax--scheme-str (str)
357 (set-buffer (geiser-syntax--font-lock-buffer))
360 (let ((font-lock-verbose nil
)) (font-lock-fontify-buffer))
364 (provide 'geiser-syntax
)
365 ;;; geiser-syntax.el ends here