Mercurial > urweb

annotate src/elisp/urweb-move.el @ 353:9390c55b9f1f

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
More indenting
author Adam Chlipala <adamc@hcoop.net>
date Sun, 12 Oct 2008 10:48:01 -0400
parents 3a1e36b14105
children 527529a083d9
rev   line source
adamc@350 1 ;;; urweb-move.el --- Buffer navigation functions for urweb-mode
adamc@350 2
adamc@350 3 ;; Based on urweb-mode:
adamc@350 4 ;; Copyright (C) 1999, 2000, 2004 Stefan Monnier <monnier@gnu.org>
adamc@350 5 ;;
adamc@350 6 ;; Modified for urweb-mode:
adamc@350 7 ;; Copyright (C) 2008 Adam Chlipala <adamc@hcoop.net>
adamc@350 8 ;;
adamc@350 9 ;; This program is free software; you can redistribute it and/or modify
adamc@350 10 ;; it under the terms of the GNU General Public License as published by
adamc@350 11 ;; the Free Software Foundation; either version 2 of the License, or
adamc@350 12 ;; (at your option) any later version.
adamc@350 13 ;;
adamc@350 14 ;; This program is distributed in the hope that it will be useful,
adamc@350 15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
adamc@350 16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
adamc@350 17 ;; GNU General Public License for more details.
adamc@350 18 ;;
adamc@350 19 ;; You should have received a copy of the GNU General Public License
adamc@350 20 ;; along with this program; if not, write to the Free Software
adamc@350 21 ;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
adamc@350 22
adamc@350 23
adamc@350 24 ;;; Commentary:
adamc@350 25
adamc@350 26
adamc@350 27 ;;; Code:
adamc@350 28
adamc@350 29 (eval-when-compile (require 'cl))
adamc@350 30 (require 'urweb-util)
adamc@350 31 (require 'urweb-defs)
adamc@350 32
adamc@350 33 (defsyntax urweb-internal-syntax-table
adamc@350 34 '((?_ . "w")
adamc@350 35 (?' . "w")
adamc@350 36 (?. . "w"))
adamc@350 37 "Syntax table used for internal urweb-mode operation."
adamc@350 38 :copy urweb-mode-syntax-table)
adamc@350 39
adamc@350 40 ;;;
adamc@350 41 ;;; various macros
adamc@350 42 ;;;
adamc@350 43
adamc@350 44 (defmacro urweb-with-ist (&rest r)
adamc@350 45 (let ((ost-sym (make-symbol "oldtable")))
adamc@350 46 `(let ((,ost-sym (syntax-table))
adamc@350 47 (case-fold-search nil)
adamc@350 48 (parse-sexp-lookup-properties t)
adamc@350 49 (parse-sexp-ignore-comments t))
adamc@350 50 (unwind-protect
adamc@350 51 (progn (set-syntax-table urweb-internal-syntax-table) . ,r)
adamc@350 52 (set-syntax-table ,ost-sym)))))
adamc@350 53 (def-edebug-spec urweb-with-ist t)
adamc@350 54
adamc@350 55 (defmacro urweb-move-if (&rest body)
adamc@350 56 (let ((pt-sym (make-symbol "point"))
adamc@350 57 (res-sym (make-symbol "result")))
adamc@350 58 `(let ((,pt-sym (point))
adamc@350 59 (,res-sym ,(cons 'progn body)))
adamc@350 60 (unless ,res-sym (goto-char ,pt-sym))
adamc@350 61 ,res-sym)))
adamc@350 62 (def-edebug-spec urweb-move-if t)
adamc@350 63
adamc@350 64 (defmacro urweb-point-after (&rest body)
adamc@350 65 `(save-excursion
adamc@350 66 ,@body
adamc@350 67 (point)))
adamc@350 68 (def-edebug-spec urweb-point-after t)
adamc@350 69
adamc@350 70 ;;
adamc@350 71
adamc@350 72 (defvar urweb-op-prec
adamc@350 73 (urweb-preproc-alist
adamc@350 74 '((("UNION" "INTERSECT" "EXCEPT") . 0)
adamc@350 75 (("AND" "OR") . 1)
adamc@350 76 ((">" ">=" "<>" "<" "<=" "=") . 4)
adamc@350 77 (("+" "-" "^") . 6)
adamc@350 78 (("/" "*" "%") . 7)
adamc@350 79 (("++" "--") 8)
adamc@350 80 (("NOT") 9)
adamc@353 81 (("~") 10)))
adamc@350 82 "Alist of Ur/Web infix operators and their precedence.")
adamc@350 83
adamc@350 84 (defconst urweb-syntax-prec
adamc@350 85 (urweb-preproc-alist
adamc@350 86 `(((";" ",") . 20)
adamc@350 87 (("=>" "d=" "=of") . (65 . 40))
adamc@350 88 ("|" . (47 . 30))
adamc@350 89 (("case" "of" "fn") . 45)
adamc@350 90 (("if" "then" "else" ) . 50)
adamc@350 91 (("<-") . 55)
adamc@350 92 ("||" . 70)
adamc@350 93 ("&&" . 80)
adamc@350 94 ((":" "::" ":::" ":>") . 90)
adamc@350 95 ("->" . 95)
adamc@350 96 ("with" . 100)
adamc@350 97 (,(cons "end" urweb-begin-syms) . 10000)))
adamc@350 98 "Alist of pseudo-precedence of syntactic elements.")
adamc@350 99
adamc@350 100 (defun urweb-op-prec (op dir)
adamc@350 101 "Return the precedence of OP or nil if it's not an infix.
adamc@350 102 DIR should be set to BACK if you want to precedence w.r.t the left side
adamc@350 103 and to FORW for the precedence w.r.t the right side.
adamc@350 104 This assumes that we are `looking-at' the OP."
adamc@350 105 (when op
adamc@350 106 (let ((sprec (cdr (assoc op urweb-syntax-prec))))
adamc@350 107 (cond
adamc@350 108 ((consp sprec) (if (eq dir 'back) (car sprec) (cdr sprec)))
adamc@350 109 (sprec sprec)
adamc@350 110 (t
adamc@350 111 (let ((prec (cdr (assoc op urweb-op-prec))))
adamc@350 112 (when prec (+ prec 100))))))))
adamc@350 113
adamc@350 114 ;;
adamc@350 115
adamc@350 116 (defun urweb-forward-spaces () (forward-comment 100000))
adamc@350 117 (defun urweb-backward-spaces () (forward-comment -100000))
adamc@350 118
adamc@350 119
adamc@350 120 ;;
adamc@350 121 ;; moving forward around matching symbols
adamc@350 122 ;;
adamc@350 123
adamc@350 124 (defun urweb-looking-back-at (re)
adamc@350 125 (save-excursion
adamc@350 126 (when (= 0 (skip-syntax-backward "w_")) (backward-char))
adamc@350 127 (looking-at re)))
adamc@350 128
adamc@350 129 (defun urweb-find-match-forward (this match)
adamc@350 130 "Only works for word matches."
adamc@350 131 (let ((level 1)
adamc@350 132 (forward-sexp-function nil)
adamc@350 133 (either (concat this "\\|" match)))
adamc@350 134 (while (> level 0)
adamc@350 135 (forward-sexp 1)
adamc@350 136 (while (not (or (eobp) (urweb-looking-back-at either)))
adamc@350 137 (condition-case () (forward-sexp 1) (error (forward-char 1))))
adamc@350 138 (setq level
adamc@350 139 (cond
adamc@350 140 ((and (eobp) (> level 1)) (error "Unbalanced"))
adamc@350 141 ((urweb-looking-back-at this) (1+ level))
adamc@350 142 ((urweb-looking-back-at match) (1- level))
adamc@350 143 (t (error "Unbalanced")))))
adamc@350 144 t))
adamc@350 145
adamc@350 146 (defun urweb-find-match-backward (this match)
adamc@350 147 (let ((level 1)
adamc@350 148 (forward-sexp-function nil)
adamc@350 149 (either (concat this "\\|" match)))
adamc@350 150 (while (> level 0)
adamc@350 151 (backward-sexp 1)
adamc@350 152 (while (not (or (bobp) (looking-at either)))
adamc@350 153 (condition-case () (backward-sexp 1) (error (backward-char 1))))
adamc@350 154 (setq level
adamc@350 155 (cond
adamc@350 156 ((and (bobp) (> level 1)) (error "Unbalanced"))
adamc@350 157 ((looking-at this) (1+ level))
adamc@350 158 ((looking-at match) (1- level))
adamc@350 159 (t (error "Unbalanced")))))
adamc@350 160 t))
adamc@350 161
adamc@350 162 ;;;
adamc@350 163 ;;; read a symbol, including the special "op <sym>" case
adamc@350 164 ;;;
adamc@350 165
adamc@350 166 (defmacro urweb-move-read (&rest body)
adamc@350 167 (let ((pt-sym (make-symbol "point")))
adamc@350 168 `(let ((,pt-sym (point)))
adamc@350 169 ,@body
adamc@350 170 (when (/= (point) ,pt-sym)
adamc@350 171 (buffer-substring-no-properties (point) ,pt-sym)))))
adamc@350 172 (def-edebug-spec urweb-move-read t)
adamc@350 173
adamc@350 174 (defun urweb-poly-equal-p ()
adamc@350 175 (< (urweb-point-after (re-search-backward urweb-=-starter-re nil 'move))
adamc@350 176 (urweb-point-after (re-search-backward "=" nil 'move))))
adamc@350 177
adamc@350 178 (defun urweb-nested-of-p ()
adamc@350 179 (< (urweb-point-after
adamc@350 180 (re-search-backward urweb-non-nested-of-starter-re nil 'move))
adamc@350 181 (urweb-point-after (re-search-backward "\\<case\\>" nil 'move))))
adamc@350 182
adamc@350 183 (defun urweb-forward-sym-1 ()
adamc@350 184 (or (/= 0 (skip-syntax-forward "'w_"))
adamc@350 185 (/= 0 (skip-syntax-forward ".'"))))
adamc@350 186 (defun urweb-forward-sym ()
adamc@350 187 (let ((sym (urweb-move-read (urweb-forward-sym-1))))
adamc@350 188 (cond
adamc@350 189 ((equal "op" sym)
adamc@350 190 (urweb-forward-spaces)
adamc@350 191 (concat "op " (or (urweb-move-read (urweb-forward-sym-1)) "")))
adamc@350 192 ((equal sym "=")
adamc@350 193 (save-excursion
adamc@350 194 (urweb-backward-sym-1)
adamc@350 195 (if (urweb-poly-equal-p) "=" "d=")))
adamc@350 196 ((equal sym "of")
adamc@350 197 (save-excursion
adamc@350 198 (urweb-backward-sym-1)
adamc@350 199 (if (urweb-nested-of-p) "of" "=of")))
adamc@350 200 ;; ((equal sym "datatype")
adamc@350 201 ;; (save-excursion
adamc@350 202 ;; (urweb-backward-sym-1)
adamc@350 203 ;; (urweb-backward-spaces)
adamc@350 204 ;; (if (eq (preceding-char) ?=) "=datatype" sym)))
adamc@350 205 (t sym))))
adamc@350 206
adamc@350 207 (defun urweb-backward-sym-1 ()
adamc@350 208 (or (/= 0 (skip-syntax-backward ".'"))
adamc@350 209 (/= 0 (skip-syntax-backward "'w_"))))
adamc@350 210 (defun urweb-backward-sym ()
adamc@350 211 (let ((sym (urweb-move-read (urweb-backward-sym-1))))
adamc@350 212 (when sym
adamc@350 213 ;; FIXME: what should we do if `sym' = "op" ?
adamc@350 214 (let ((point (point)))
adamc@350 215 (urweb-backward-spaces)
adamc@350 216 (if (equal "op" (urweb-move-read (urweb-backward-sym-1)))
adamc@350 217 (concat "op " sym)
adamc@350 218 (goto-char point)
adamc@350 219 (cond
adamc@350 220 ((string= sym "=") (if (urweb-poly-equal-p) "=" "d="))
adamc@350 221 ((string= sym "of") (if (urweb-nested-of-p) "of" "=of"))
adamc@350 222 ;; ((string= sym "datatype")
adamc@350 223 ;; (save-excursion (urweb-backward-spaces)
adamc@350 224 ;; (if (eq (preceding-char) ?=) "=datatype" sym)))
adamc@350 225 (t sym)))))))
adamc@350 226
adamc@350 227
adamc@350 228 (defun urweb-backward-sexp (prec)
adamc@350 229 "Move one sexp backward if possible, or one char else.
adamc@350 230 Returns t if the move indeed moved through one sexp and nil if not.
adamc@350 231 PREC is the precedence currently looked for."
adamc@350 232 (let ((parse-sexp-lookup-properties t)
adamc@350 233 (parse-sexp-ignore-comments t))
adamc@350 234 (urweb-backward-spaces)
adamc@350 235 (let* ((op (urweb-backward-sym))
adamc@350 236 (op-prec (urweb-op-prec op 'back))
adamc@350 237 match)
adamc@350 238 (cond
adamc@350 239 ((not op)
adamc@350 240 (let ((point (point)))
adamc@350 241 (ignore-errors (let ((forward-sexp-function nil)) (backward-sexp 1)))
adamc@350 242 (if (/= point (point)) t (ignore-errors (backward-char 1)) nil)))
adamc@350 243 ;; stop as soon as precedence is smaller than `prec'
adamc@350 244 ((and prec op-prec (>= prec op-prec)) nil)
adamc@350 245 ;; special rules for nested constructs like if..then..else
adamc@350 246 ((and (or (not prec) (and prec op-prec))
adamc@350 247 (setq match (second (assoc op urweb-close-paren))))
adamc@350 248 (urweb-find-match-backward (concat "\\<" op "\\>") match))
adamc@350 249 ;; don't back over open-parens
adamc@350 250 ((assoc op urweb-open-paren) nil)
adamc@350 251 ;; infix ops precedence
adamc@350 252 ((and prec op-prec) (< prec op-prec))
adamc@350 253 ;; [ prec = nil ] a new operator, let's skip the sexps until the next
adamc@350 254 (op-prec (while (urweb-move-if (urweb-backward-sexp op-prec))) t)
adamc@350 255 ;; special symbols indicating we're getting out of a nesting level
adamc@350 256 ((string-match urweb-sexp-head-symbols-re op) nil)
adamc@350 257 ;; if the op was not alphanum, then we still have to do the backward-sexp
adamc@350 258 ;; this reproduces the usual backward-sexp, but it might be bogus
adamc@350 259 ;; in this case since !@$% is a perfectly fine symbol
adamc@350 260 (t t))))) ;(or (string-match "\\sw" op) (urweb-backward-sexp prec))
adamc@350 261
adamc@350 262 (defun urweb-forward-sexp (prec)
adamc@350 263 "Moves one sexp forward if possible, or one char else.
adamc@350 264 Returns T if the move indeed moved through one sexp and NIL if not."
adamc@350 265 (let ((parse-sexp-lookup-properties t)
adamc@350 266 (parse-sexp-ignore-comments t))
adamc@350 267 (urweb-forward-spaces)
adamc@350 268 (let* ((op (urweb-forward-sym))
adamc@350 269 (op-prec (urweb-op-prec op 'forw))
adamc@350 270 match)
adamc@350 271 (cond
adamc@350 272 ((not op)
adamc@350 273 (let ((point (point)))
adamc@350 274 (ignore-errors (let ((forward-sexp-function nil)) (forward-sexp 1)))
adamc@350 275 (if (/= point (point)) t (forward-char 1) nil)))
adamc@350 276 ;; stop as soon as precedence is smaller than `prec'
adamc@350 277 ((and prec op-prec (>= prec op-prec)) nil)
adamc@350 278 ;; special rules for nested constructs like if..then..else
adamc@350 279 ((and (or (not prec) (and prec op-prec))
adamc@350 280 (setq match (cdr (assoc op urweb-open-paren))))
adamc@350 281 (urweb-find-match-forward (first match) (second match)))
adamc@350 282 ;; don't forw over close-parens
adamc@350 283 ((assoc op urweb-close-paren) nil)
adamc@350 284 ;; infix ops precedence
adamc@350 285 ((and prec op-prec) (< prec op-prec))
adamc@350 286 ;; [ prec = nil ] a new operator, let's skip the sexps until the next
adamc@350 287 (op-prec (while (urweb-move-if (urweb-forward-sexp op-prec))) t)
adamc@350 288 ;; special symbols indicating we're getting out of a nesting level
adamc@350 289 ((string-match urweb-sexp-head-symbols-re op) nil)
adamc@350 290 ;; if the op was not alphanum, then we still have to do the backward-sexp
adamc@350 291 ;; this reproduces the usual backward-sexp, but it might be bogus
adamc@350 292 ;; in this case since !@$% is a perfectly fine symbol
adamc@350 293 (t t))))) ;(or (string-match "\\sw" op) (urweb-backward-sexp prec))
adamc@350 294
adamc@350 295 (defun urweb-in-word-p ()
adamc@350 296 (and (eq ?w (char-syntax (or (char-before) ? )))
adamc@350 297 (eq ?w (char-syntax (or (char-after) ? )))))
adamc@350 298
adamc@350 299 (defun urweb-user-backward-sexp (&optional count)
adamc@350 300 "Like `backward-sexp' but tailored to the Ur/Web syntax."
adamc@350 301 (interactive "p")
adamc@350 302 (unless count (setq count 1))
adamc@350 303 (urweb-with-ist
adamc@350 304 (let ((point (point)))
adamc@350 305 (if (< count 0) (urweb-user-forward-sexp (- count))
adamc@350 306 (when (urweb-in-word-p) (forward-word 1))
adamc@350 307 (dotimes (i count)
adamc@350 308 (unless (urweb-backward-sexp nil)
adamc@350 309 (goto-char point)
adamc@350 310 (error "Containing expression ends prematurely")))))))
adamc@350 311
adamc@350 312 (defun urweb-user-forward-sexp (&optional count)
adamc@350 313 "Like `forward-sexp' but tailored to the Ur/Web syntax."
adamc@350 314 (interactive "p")
adamc@350 315 (unless count (setq count 1))
adamc@350 316 (urweb-with-ist
adamc@350 317 (let ((point (point)))
adamc@350 318 (if (< count 0) (urweb-user-backward-sexp (- count))
adamc@350 319 (when (urweb-in-word-p) (backward-word 1))
adamc@350 320 (dotimes (i count)
adamc@350 321 (unless (urweb-forward-sexp nil)
adamc@350 322 (goto-char point)
adamc@350 323 (error "Containing expression ends prematurely")))))))
adamc@350 324
adamc@350 325 ;;(defun urweb-forward-thing ()
adamc@350 326 ;; (if (= ?w (char-syntax (char-after))) (forward-word 1) (forward-char 1)))
adamc@350 327
adamc@350 328 (defun urweb-backward-arg () (urweb-backward-sexp 1000))
adamc@350 329 (defun urweb-forward-arg () (urweb-forward-sexp 1000))
adamc@350 330
adamc@350 331
adamc@350 332 (provide 'urweb-move)
adamc@350 333
adamc@350 334 ;;; urweb-move.el ends here