elisp/geiser-syntax.el

   1 ;;; geiser-syntax.el -- utilities for parsing scheme syntax
   2
   3 ;; Copyright (C) 2009, 2010 Jose Antonio Ortega Ruiz
   4
   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>.
   9
  10 ;; Start date: Sun Feb 08, 2009 15:03
  11
  12 \f
  13
  14 (require 'geiser-impl)
  15 (require 'geiser-popup)
  16 (require 'geiser-base)
  17
  18 (require 'scheme)
  19
  20 (eval-when-compile (require 'cl))
  21
  22 \f
  23 ;;; Indentation:
  24
  25 (defmacro geiser-syntax--scheme-indent (&rest pairs)
  26   `(progn ,@(mapcar (lambda (p)
  27                       `(put ',(car p) 'scheme-indent-function ',(cadr p)))
  28                     pairs)))
  29
  30 (geiser-syntax--scheme-indent
  31  (begin0 1)
  32  (c-declare 0)
  33  (c-lambda 2)
  34  (case-lambda 0)
  35  (case-lambda: 0)
  36  (catch defun)
  37  (class defun)
  38  (class* defun)
  39  (compound-unit/sig 0)
  40  (define: defun)
  41  (dynamic-wind 0)
  42  (for/fold 2)
  43  (instantiate 2)
  44  (interface 1)
  45  (lambda: 1)
  46  (lambda/kw 1)
  47  (let*-values 1)
  48  (let*-values: 1)
  49  (let+ 1)
  50  (let: 1)
  51  (letrec: 1)
  52  (letrec* 1)
  53  (letrec-values 1)
  54  (letrec-values: 1)
  55  (let-values 1)
  56  (let-values: 1)
  57  (let/cc: 1)
  58  (let/ec 1)
  59  (match defun)
  60  (mixin 2)
  61  (module defun)
  62  (opt-lambda 1)
  63  (parameterize 1)
  64  (parameterize-break 1)
  65  (parameterize* 1)
  66  (pmatch defun)
  67  (quasisyntax/loc 1)
  68  (receive 2)
  69  (send* 1)
  70  (sigaction 1)
  71  (syntax-case 2)
  72  (syntax/loc 1)
  73  (type-case defun)
  74  (unit defun)
  75  (unit/sig 2)
  76  (unless 1)
  77  (when 1)
  78  (while 1)
  79  (with-fluid* 1)
  80  (with-fluids 1)
  81  (with-fluids* 1)
  82  (with-handlers 1)
  83  (with-handlers: 1)
  84  (with-method 1)
  85  (with-syntax 1))
  86
  87 \f
  88 ;;; Extra syntax keywords
  89 (defconst geiser-syntax--keywords
  90   '(("\\[\\(else\\)\\>" . 1)
  91     ("(\\(parameterize\\)\\>" . 1)))
  92
  93 (font-lock-add-keywords 'scheme-mode geiser-syntax--keywords)
  94
  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.")
  98
  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))))
 102
 103 \f
 104 ;;; A simple scheme reader
 105
 106 (defvar geiser-syntax--read/buffer-limit nil)
 107
 108 (defsubst geiser-syntax--read/eos ()
 109   (or (eobp)
 110       (and geiser-syntax--read/buffer-limit
 111            (<= geiser-syntax--read/buffer-limit (point)))))
 112
 113 (defsubst geiser-syntax--read/next-char ()
 114   (unless (geiser-syntax--read/eos)
 115     (forward-char)
 116     (char-after)))
 117
 118 (defsubst geiser-syntax--read/token (token)
 119   (geiser-syntax--read/next-char)
 120   (if (listp token) token (list token)))
 121
 122 (defsubst geiser-syntax--read/elisp ()
 123   (ignore-errors (read (current-buffer))))
 124
 125 (defun geiser-syntax--read/symbol ()
 126   (with-syntax-table scheme-mode-syntax-table
 127     (when (re-search-forward "\\(\\sw\\|\\s_\\)+" nil t)
 128       (make-symbol (match-string 0)))))
 129
 130 (defun geiser-syntax--read/matching (open close)
 131   (let ((count 1)
 132         (p (1+ (point))))
 133     (while (and (> count 0)
 134                 (geiser-syntax--read/next-char))
 135       (cond ((looking-at-p open) (setq count (1+ count)))
 136             ((looking-at-p close) (setq count (1- count)))))
 137     (buffer-substring-no-properties p (point))))
 138
 139 (defsubst geiser-syntax--read/unprintable ()
 140   (geiser-syntax--read/token
 141    (cons 'unprintable (geiser-syntax--read/matching "<" ">"))))
 142
 143 (defun geiser-syntax--read/skip-comment ()
 144   (while (and (geiser-syntax--read/next-char)
 145               (nth 8 (syntax-ppss))))
 146   (geiser-syntax--read/next-token))
 147
 148 (defun geiser-syntax--read/next-token ()
 149   (skip-syntax-forward "->")
 150   (if (geiser-syntax--read/eos) '(eob)
 151     (case (char-after)
 152       (?\; (geiser-syntax--read/skip-comment))
 153       ((?\( ?\[) (geiser-syntax--read/token 'lparen))
 154       ((?\) ?\]) (geiser-syntax--read/token 'rparen))
 155       (?. (if (memq (car (syntax-after (1+ (point)))) '(0 11 12))
 156               (geiser-syntax--read/token 'dot)
 157             (cons 'atom (geiser-syntax--read/elisp))))
 158       (?\# (case (geiser-syntax--read/next-char)
 159              ('nil '(eob))
 160              (?| (geiser-syntax--read/skip-comment))
 161              (?: (if (geiser-syntax--read/next-char)
 162                      (cons 'kwd (geiser-syntax--read/elisp))
 163                    '(eob)))
 164              (?\\ (cons 'char (geiser-syntax--read/elisp)))
 165              (?\( (geiser-syntax--read/token 'vectorb))
 166              (?\< (geiser-syntax--read/unprintable))
 167              ((?' ?` ?,) (geiser-syntax--read/next-token))
 168              (t (let ((tok (geiser-syntax--read/symbol)))
 169                   (if tok (cons 'atom (intern (format "#%s" tok)))
 170                     (geiser-syntax--read/next-token))))))
 171       (?\' (geiser-syntax--read/token '(quote . quote)))
 172       (?\` (geiser-syntax--read/token
 173             `(backquote . ,backquote-backquote-symbol)))
 174       (?, (if (eq (geiser-syntax--read/next-char) ?@)
 175               (geiser-syntax--read/token
 176                `(splice . ,backquote-splice-symbol))
 177             `(unquote . ,backquote-unquote-symbol)))
 178       (?\" (cons 'string (geiser-syntax--read/elisp)))
 179       (t (cons 'atom (geiser-syntax--read/symbol))))))
 180
 181 (defsubst geiser-syntax--read/match (&rest tks)
 182   (let ((token (geiser-syntax--read/next-token)))
 183     (if (memq (car token) tks) token
 184       (error "Unexpected token: %s" token))))
 185
 186 (defsubst geiser-syntax--read/skip-until (&rest tks)
 187   (let (token)
 188     (while (and (not (memq (car token) tks))
 189                 (not (eq (car token) 'eob)))
 190       (setq token (geiser-syntax--read/next-token)))
 191     token))
 192
 193 (defsubst geiser-syntax--read/try (&rest tks)
 194   (let ((p (point))
 195         (tk (ignore-errors (apply 'geiser-syntax--read/match tks))))
 196     (unless tk (goto-char p))
 197     tk))
 198
 199 (defun geiser-syntax--read/list ()
 200   (cond ((geiser-syntax--read/try 'dot)
 201          (let ((tail (geiser-syntax--read)))
 202            (geiser-syntax--read/skip-until 'eob 'rparen)
 203            tail))
 204         ((geiser-syntax--read/try 'rparen 'eob) nil)
 205         (t (cons (geiser-syntax--read)
 206                  (geiser-syntax--read/list)))))
 207
 208 (defun geiser-syntax--read ()
 209   (let ((token (geiser-syntax--read/next-token))
 210         (max-lisp-eval-depth (max max-lisp-eval-depth 3000)))
 211     (case (car token)
 212       (eob nil)
 213       (lparen (geiser-syntax--read/list))
 214       (vectorb (apply 'vector (geiser-syntax--read/list)))
 215       ((quote backquote unquote splice) (list (cdr token)
 216                                               (geiser-syntax--read)))
 217       (kwd (intern (format ":%s" (cdr token))))
 218       (unprintable (format "#<%s>" (cdr token)))
 219       ((char string atom) (cdr token))
 220       (t (error "Reading scheme syntax: unexpected token: %s" token)))))
 221
 222 (defun geiser-syntax--read-from-string (string &optional start end)
 223   (when (stringp string)
 224     (let* ((start (or start 0))
 225            (end (or end (length string)))
 226            (max-lisp-eval-depth (max max-lisp-eval-depth (- end start))))
 227       (with-temp-buffer
 228         (save-excursion (insert string))
 229         (cons (ignore-errors (geiser-syntax--read)) (point))))))
 230
 231 (defsubst geiser-syntax--form-after-point (&optional boundary)
 232   (let ((geiser-syntax--read/buffer-limit (and (numberp boundary) boundary)))
 233     (save-excursion (values (geiser-syntax--read) (point)))))
 234
 235 \f
 236 ;;; Code parsing:
 237
 238 (defsubst geiser-syntax--symbol-at-point ()
 239   (and (not (nth 8 (syntax-ppss)))
 240        (let ((s (thing-at-point 'symbol)))
 241          (and s
 242               (not (equal s "."))
 243               (make-symbol (substring-no-properties s))))))
 244
 245 (defsubst geiser-syntax--skip-comment/string ()
 246   (let ((pos (nth 8 (syntax-ppss))))
 247     (goto-char (or pos (point)))
 248     pos))
 249
 250 (defsubst geiser-syntax--nesting-level ()
 251   (or (nth 0 (syntax-ppss)) 0))
 252
 253 (defsubst geiser-syntax--pair-length (p)
 254   (if (cdr (last p)) (1+ (safe-length p)) (length p)))
 255
 256 (defun geiser-syntax--shallow-form (boundary)
 257   (when (looking-at-p "\\s(")
 258     (save-excursion
 259       (forward-char)
 260       (let ((elems))
 261         (ignore-errors
 262           (while (< (point) boundary)
 263             (skip-syntax-forward "-<>")
 264             (when (<= (point) boundary)
 265               (forward-sexp)
 266               (let ((s (thing-at-point 'symbol)))
 267                 (cond ((not s) (push s elems))
 268                       ((not (equal "." s)) (push (make-symbol s) elems)))))))
 269         (nreverse elems)))))
 270
 271 (defun geiser-syntax--scan-sexps (&optional begin)
 272   (let* ((fst (geiser-syntax--symbol-at-point))
 273          (smth (or fst (not (looking-at-p "[\s \s)\s>\s<\n]"))))
 274          (path (and fst `((,fst 0)))))
 275     (save-excursion
 276       (while (not (zerop (geiser-syntax--nesting-level)))
 277         (let ((boundary (point)))
 278           (geiser-syntax--skip-comment/string)
 279           (backward-up-list)
 280           (let ((form (geiser-syntax--shallow-form boundary)))
 281             (when (and (listp form) (car form) (symbolp (car form)))
 282               (let* ((len (geiser-syntax--pair-length form))
 283                      (pos (if smth (1- len) (progn (setq smth t) len)))
 284                      (prev (and (> pos 1) (nth (1- pos) form)))
 285                      (prev (and (keywordp prev) (list prev))))
 286                 (push `(,(car form) ,pos ,@prev) path)))))))
 287     (mapcar (lambda (e) (cons (format "%s" (car e)) (cdr e)))
 288             (nreverse path))))
 289
 290 (defsubst geiser-syntax--binding-form-p (bfs sbfs f)
 291   (or (memq f '(define define* define-syntax define-syntax-rule
 292                 lambda let let* letrec parameterize))
 293       (memq f bfs)
 294       (memq f sbfs)))
 295
 296 (defsubst geiser-syntax--binding-form*-p (sbfs f)
 297   (or (eq 'let* f) (memq f sbfs)))
 298
 299 (defsubst geiser-syntax--if-symbol (x) (and (symbolp x) x))
 300 (defsubst geiser-syntax--if-list (x) (and (listp x) x))
 301 (defsubst geiser-syntax--normalize (vars)
 302   (mapcar (lambda (i) (if (listp i) (car i) i)) vars))
 303
 304 (defun geiser-syntax--linearize (form)
 305   (cond ((not (listp form)) (list form))
 306         ((null form) nil)
 307         (t (cons (car form) (geiser-syntax--linearize (cdr form))))))
 308
 309 (defun geiser-syntax--scan-locals (bfs sbfs form partial locals)
 310   (if (or (null form) (not (listp form)))
 311       (geiser-syntax--normalize locals)
 312     (if (not (geiser-syntax--binding-form-p bfs sbfs (car form)))
 313         (geiser-syntax--scan-locals bfs sbfs
 314                                     (car (last form)) partial locals)
 315       (let* ((head (car form))
 316              (name (geiser-syntax--if-symbol (cadr form)))
 317              (names (if name (geiser-syntax--if-list (caddr form))
 318                       (geiser-syntax--if-list (cadr form))))
 319              (rest (if name (cdddr form) (cddr form)))
 320              (use-names (or rest
 321                             (not partial)
 322                             (geiser-syntax--binding-form*-p sbfs
 323                                                             head))))
 324         (when name (push name locals))
 325         (when use-names
 326           (dolist (n (geiser-syntax--linearize names))
 327             (push n locals)))
 328         (dolist (f (butlast rest))
 329           (when (and (listp f) (eq (car f) 'define))
 330             (push (cadr f) locals)))
 331         (geiser-syntax--scan-locals bfs sbfs
 332                                     (car (last (or rest names)))
 333                                     partial
 334                                     locals)))))
 335
 336 (defun geiser-syntax--locals-around-point (bfs sbfs)
 337   (when (eq major-mode 'scheme-mode)
 338     (save-excursion
 339       (let* ((sym (unless (geiser-syntax--skip-comment/string)
 340                     (symbol-at-point)))
 341              (boundary (point)))
 342         (while (not (zerop (geiser-syntax--nesting-level)))
 343           (backward-up-list))
 344         (multiple-value-bind (form end)
 345             (geiser-syntax--form-after-point boundary)
 346           (delq sym
 347                 (geiser-syntax--scan-locals bfs sbfs form
 348                                             (> end boundary) '())))))))
 349
 350 \f
 351 ;;; Fontify strings as Scheme code:
 352
 353 (defun geiser-syntax--font-lock-buffer ()
 354   (let ((name " *geiser font lock*"))
 355     (or (get-buffer name)
 356         (let ((buffer (get-buffer-create name)))
 357           (set-buffer buffer)
 358           (let ((geiser-default-implementation
 359                  (or geiser-default-implementation
 360                      (car geiser-active-implementations))))
 361             (scheme-mode))
 362           buffer))))
 363
 364 (defun geiser-syntax--scheme-str (str)
 365   (save-current-buffer
 366     (set-buffer (geiser-syntax--font-lock-buffer))
 367     (erase-buffer)
 368     (insert str)
 369     (let ((font-lock-verbose nil)) (font-lock-fontify-buffer))
 370     (buffer-string)))
 371
 372 \f
 373 (provide 'geiser-syntax)
 374 ;;; geiser-syntax.el ends here