mdw@git.distorted.org.uk Git - sod/blob - src/parser/parser-test.lisp

   1 ;;; -*-lisp-*-
   2 ;;;
   3 ;;; Test parser infrastructure
   4 ;;;
   5 ;;; (c) 2009 Straylight/Edgeware
   6 ;;;
   7
   8 ;;;----- Licensing notice ---------------------------------------------------
   9 ;;;
  10 ;;; This file is part of the Sensble Object Design, an object system for C.
  11 ;;;
  12 ;;; SOD is free software; you can redistribute it and/or modify
  13 ;;; it under the terms of the GNU General Public License as published by
  14 ;;; the Free Software Foundation; either version 2 of the License, or
  15 ;;; (at your option) any later version.
  16 ;;;
  17 ;;; SOD is distributed in the hope that it will be useful,
  18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;;; GNU General Public License for more details.
  21 ;;;
  22 ;;; You should have received a copy of the GNU General Public License
  23 ;;; along with SOD; if not, write to the Free Software Foundation,
  24 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 (cl:in-package #:sod-test)
  27
  28 (defclass test-parser (test-case)
  29   ())
  30 (add-test *sod-test-suite* (get-suite test-parser))
  31
  32 ;;;--------------------------------------------------------------------------
  33 ;;; Utilities.
  34
  35 (defmacro assert-parse
  36     ((string value winp consumedp &key (scanner (gensym "SCANNER-")))
  37      &body parser)
  38   (once-only (string value winp consumedp)
  39     (with-gensyms (my-value my-winp my-consumedp label what)
  40       `(let ((,scanner (make-string-scanner ,string)))
  41          (multiple-value-bind (,my-value ,my-winp ,my-consumedp)
  42              (with-parser-context
  43                  (character-scanner-context :scanner ,scanner)
  44                (parse ,@parser))
  45            (flet ((,label (,what)
  46                     (format nil "~A; parsing ~S with ~S"
  47                             ,what ,string ',@parser)))
  48              (cond (,winp
  49                     (assert-true ,my-winp (,label "winp"))
  50                     (if (eq ,value t)
  51                         (assert-not-eql ,my-value nil
  52                                         (,label "parser result"))
  53                         (assert-equal ,my-value ,value
  54                                       (,label "parser result"))))
  55                    (t
  56                     (assert-false ,my-winp (,label "winp"))
  57                     (assert-true (and (null (set-difference ,my-value ,value
  58                                                             :test #'equal))
  59                                       (null (set-difference ,value ,my-value
  60                                                             :test #'equal)))
  61                                  (,label "failure indicator"))))
  62              (if ,consumedp
  63                  (assert-true ,my-consumedp (,label "consumedp"))
  64                  (assert-false ,my-consumedp (,label "consumedp")))))))))
  65
  66 ;;;--------------------------------------------------------------------------
  67 ;;; Simple parser tests.
  68 ;;;
  69 ;;; This lot causes SBCL to warn like a mad thing.  It's too clever for us,
  70 ;;; and does half of the work at compile time!
  71
  72 (def-test-method test-simple ((test test-parser) :run nil)
  73   "Test simple atomic parsers, because we rely on them later."
  74
  75   ;; Characters match themselves.  For a character known only at run-time,
  76   ;; use (char CH).
  77   (assert-parse ("abcd" #\a t t) #\a)
  78   (let ((ch #\b))
  79     (assert-parse ("abcd" '(#\b) nil nil) (char ch)))
  80
  81   ;; A character can't match at EOF.
  82   (assert-parse ("" '(#\z) nil nil) #\z)
  83
  84   ;; All characters match :any; but EOF isn't a character.
  85   (assert-parse ("z" #\z t t) :any)
  86   (assert-parse ("" '(:any) nil nil) :any)
  87
  88   ;; The parser (satisfies PREDICATE) succeeds if the PREDICATE returns
  89   ;; true when applied to the current character.
  90   (assert-parse ("a" #\a t t) (satisfies alpha-char-p))
  91   (assert-parse ("0" '(alpha-char-p) nil nil) (satisfies alpha-char-p))
  92
  93   ;; The parser (not CHAR) matches a character other than CHAR; but it won't
  94   ;; match EOF.
  95   (assert-parse ("a" #\a t t) (not #\b))
  96   (assert-parse ("b" '((not #\b)) nil nil) (not #\b))
  97   (assert-parse ("" '((not #\b)) nil nil) (not #\b))
  98
  99   ;; But :eof matches only at EOF.
 100   (assert-parse ("" :eof t nil) :eof)
 101   (assert-parse ("abcd" '(:eof) nil nil) :eof)
 102
 103   ;; Strings match themselves without consuming if they fail.
 104   (assert-parse ("abcd" "ab" t t) "ab")
 105   (assert-parse ("abcd" '("cd") nil nil) "cd"))
 106
 107 (def-test-method test-sequence ((test test-parser) :run nil)
 108
 109   ;; An empty sequence always succeeds and never consumes.  And provokes
 110   ;; warnings: don't do this.
 111   (assert-parse ("" :win t nil) (seq () :win))
 112   (assert-parse ("abcd" :win t nil) (seq () :win))
 113
 114   ;; A `seq' matches the individual parsers in order, and binds their results
 115   ;; to variables -- if given.  The result is the value of the body.  If any
 116   ;; parser fails having consumed input, then input stays consumed.  There's
 117   ;; no backtracking.
 118   (assert-parse ("abcd" '(#\a . #\c) t t)
 119     (seq ((foo #\a) #\b (bar #\c)) (cons foo bar)))
 120   (assert-parse ("abcd" '(#\c) nil t)
 121     (seq ((foo #\a) (bar #\c)) (cons foo bar)))
 122   (assert-parse ("abcd" '(#\c) nil nil)
 123     (seq ((bar #\c) (foo #\a)) (cons foo bar))))
 124
 125 (def-test-method test-repeat ((test test-parser) :run nil)
 126
 127   ;; A `many' matches a bunch of similar things in a row.  You can compute a
 128   ;; result using `do'-like accumulation.
 129   (assert-parse ("aaaab" 4 t t) (many (acc 0 (1+ acc)) #\a))
 130
 131   ;; The default minimum is zero; so the parser always succeeds.
 132   (assert-parse ("aaaab" 0 t nil) (many (acc 0 (1+ acc)) #\b))
 133
 134   ;; You can provide an explicit minimum.  Then the match might fail.
 135   (assert-parse ("aabb" 2 t t) (many (acc 0 (1+ acc) :min 2) #\a))
 136   (assert-parse ("aabb" '(#\a) nil t) (many (acc 0 (1+ acc) :min 3) #\a))
 137
 138   ;; You can also provide an explicit maximum.  This will cause the parser to
 139   ;; stop searching, but it can't make it fail.
 140   (assert-parse ("aaaab" 3 t t) (many (acc 0 (1+ acc) :max 3) #\a))
 141
 142   ;; You can provide both a maximum and a minimum at the same time.  If
 143   ;; they're consistent, you won't be surprised.  If they aren't, then the
 144   ;; maximum wins and the minimum is simply ignored (currently).
 145   (assert-parse ("aaaaab" 4 t t)
 146     (many (acc 0 (1+ acc) :min 3 :max 4) #\a))
 147   (assert-parse ("aabbbb" '(#\a) nil t)
 148     (many (acc 0 (1+ acc) :min 3 :max 4) #\a))
 149   (assert-parse ("aaabbb" 3 t t)
 150     (many (acc 0 (1+ acc) :min 3 :max 3) #\a))
 151   (assert-parse ("aaabbb" 3 t t)
 152     (many (acc 0 (1+ acc) :min 17 :max 3) #\a))
 153
 154   ;; You can provide a separator.  The `many' parser will look for the
 155   ;; separator between each of the main items, but will ignore the results.
 156   (assert-parse ("a,a,abc" 3 t t) (many (acc 0 (1+ acc)) #\a #\,))
 157   (assert-parse ("a,a,abc" 2 t t) (many (acc 0 (1+ acc) :max 2) #\a #\,))
 158
 159   ;; If `many' sees a separator then by default it commits to finding another
 160   ;; item; so this can cause a parse to fail.
 161   (assert-parse ("a,a,bc" '(#\a) nil t) (many (acc 0 (1+ acc)) #\a #\,))
 162   (assert-parse ("abc" 1 t t) (many (acc 0 (1+ acc)) #\a #\,))
 163
 164   ;; If you specify a separator then the default minimum number of
 165   ;; repetitions becomes 1 rather than 0.  But you can override this
 166   ;; explicitly.
 167   (assert-parse ("bc" '(#\a) nil nil) (many (acc 0 (1+ acc)) #\a #\,))
 168   (assert-parse ("bc" 0 t nil) (many (acc 0 (1+ acc) :min 0) #\a #\,))
 169
 170   ;; The parser will fail looking for a separator if there aren't enough
 171   ;; items.
 172   (assert-parse ("a,abc" '(#\,) nil t)
 173     (many (acc 0 (1+ acc) :min 3) #\a #\,))
 174
 175   ;; You can override the commit-on-separator behaviour by using :commit.
 176   ;; This makes a trailing separator legal (but optional), so it also affects
 177   ;; the behaviour regarding maximum and minimum repetitions.  (Commitment is
 178   ;; irrelevant if you don't have a separator.)
 179   (assert-parse ("a,a,bc" 2 t t)
 180     (many (acc 0 (1+ acc) :commitp nil) #\a #\,))
 181   (assert-parse ("a,a,abc" 3 t t)
 182     (many (acc 0 (1+ acc) :commitp nil) #\a #\,))
 183   (assert-parse ("a,a,a,bc" 3 t t)
 184     (seq ((n (many (acc 0 (1+ acc) :max 3 :commitp t) #\a #\,))
 185           #\,)
 186       n))
 187   (assert-parse ("a,a,a,bc" 3 t t)
 188     (seq ((n (many (acc 0 (1+ acc) :max 3 :commitp nil) #\a #\,))
 189           #\b)
 190       n))
 191   (assert-parse ("a,a,bc" '(#\a) nil t)
 192     (many (acc 0 (1+ acc) :min 3 :commitp nil) #\a #\,))
 193
 194   ;; The `many' parser won't backtrack.  The `many' eats as many `a's as
 195   ;; possible; asking for another one is sure to fail.
 196   (assert-parse ("aaaabc" '(#\a) nil t) (and (skip-many () #\a) #\a)))
 197
 198 (def-test-method test-repeat-hairy ((test test-parser) :run nil)
 199   ;; The `many' expander is very hairy and does magical things if it notices
 200   ;; that some of its arguments are constants.  So here we test a number of
 201   ;; the above things again, using variables so that it has to produce code
 202   ;; which makes decisions at run-time.  (I've no doubt that SBCL will issue
 203   ;; an infinite number of notes explaining how clever it is and how it can
 204   ;; do it all at compile-time anyway.  Of course, suppressing these notes is
 205   ;; the main reason `many' is so hairy anyway.)
 206
 207   (let ((zero 0) (two 2) (three 3) (yes t) (no nil))
 208
 209     ;; Minima.
 210     (assert-parse ("aaaab" 4 t t) (many (acc 0 (1+ acc) :min zero) #\a))
 211     (assert-parse ("aaaab" 0 t nil) (many (acc 0 (1+ acc) :min zero) #\b))
 212     (assert-parse ("aabb" 2 t t) (many (acc 0 (1+ acc) :min two) #\a))
 213     (assert-parse ("aabb" '(#\a) nil t)
 214       (many (acc 0 (1+ acc) :min three) #\a))
 215
 216     ;; Maxima.
 217     (assert-parse ("aaaab" 4 t t) (many (acc 0 (1+ acc) :max no) #\a))
 218     (assert-parse ("aaaab" 3 t t) (many (acc 0 (1+ acc) :max three) #\a))
 219
 220     ;; And now together with separators and commitment.  Oh, my.
 221     (assert-parse ("a,a,a,bc" 3 t t)
 222       (many (acc 0 (1+ acc) :commitp no) #\a #\,))
 223     (assert-parse ("a,a,a,bc" '(#\a) nil t)
 224       (many (acc 0 (1+ acc) :commitp yes) #\a #\,))
 225     (assert-parse ("a,a,bc" '(#\a) nil t)
 226       (many (acc 0 (1+ acc) :min three :commitp yes) #\a #\,))
 227     (assert-parse ("a,a,bc" '(#\a) nil t)
 228       (many (acc 0 (1+ acc) :min 3 :commitp yes) #\a #\,))
 229     (assert-parse ("a,a,bc" '(#\a) nil t)
 230       (many (acc 0 (1+ acc) :min three :commitp t) #\a #\,))
 231     (assert-parse ("a,a,a,bc" 3 t t)
 232       (seq ((n (many (acc 0 (1+ acc) :max three :commitp no) #\a #\,)) #\b)
 233         n))
 234     (assert-parse ("a,a,a,bc" 3 t t)
 235       (seq ((n (many (acc 0 (1+ acc) :max three :commitp yes) #\a #\,)) #\,)
 236         n))
 237     (assert-parse ("a,a,a,bc" 3 t t)
 238       (seq ((n (many (acc 0 (1+ acc) :max 3 :commitp no) #\a #\,)) #\b)
 239         n))
 240     (assert-parse ("a,a,a,bc" 3 t t)
 241       (seq ((n (many (acc 0 (1+ acc) :max 3 :commitp yes) #\a #\,)) #\,)
 242         n))
 243     (assert-parse ("a,a,a,bc" 3 t t)
 244       (seq ((n (many (acc 0 (1+ acc) :max three :commitp nil) #\a #\,)) #\b)
 245         n))
 246     (assert-parse ("a,a,a,bc" 3 t t)
 247       (seq ((n (many (acc 0 (1+ acc) :max three :commitp t) #\a #\,)) #\,)
 248         n))))
 249
 250 (def-test-method test-alternate ((test test-parser) :run nil)
 251
 252   ;; An `or' matches the first parser that either succeeds or fails having
 253   ;; consumed input.
 254   (assert-parse ("abcd" #\a t t) (or #\a #\b))
 255   (assert-parse ("abcd" #\a t t) (or #\b #\a))
 256   (assert-parse ("abcd" '(#\b #\c) nil nil) (or #\b #\c))
 257
 258   ;; Strings don't consume if they fail.
 259   (assert-parse ("abcd" "ab" t t) (or "cd" "ab"))
 260   (assert-parse ("abcd" "ab" t t) (or "ad" "ab"))
 261   (assert-parse ("abcd" '("ad" "ac") nil nil) (or "ad" "ac"))
 262
 263   ;; But `seq' will if some component consumes.
 264   (assert-parse ("abcd" '(#\d) nil t) (or (and #\a #\d) "ab"))
 265   (assert-parse ("abcd" "ab" t t) (or (and #\c #\d) "ab"))
 266
 267   ;; We can tame this using `peek' which rewinds the source if its argument
 268   ;; fails, so as to hide consumption of input.
 269   (assert-parse ("abcd" "ab" t t) (or (peek (and #\a #\d)) "ab"))
 270   (assert-parse ("abcd" '(#\a #\b "cd") t t)
 271     (seq ((foo (peek (seq ((foo #\a) (bar #\b)) (list foo bar))))
 272           (bar "cd"))
 273       (append foo (list bar))))
 274
 275   ;; Failure indicators are union'd if they all fail.
 276   (assert-parse ("abcd" '(#\q #\x #\z) nil nil)
 277     (or #\q (peek (and #\a (or #\x #\q))) #\z))
 278
 279   ;; But if any of them consumed input then you only get the indicators from
 280   ;; the consuming branch, because we committed to it when we consumed the
 281   ;; input.
 282   (assert-parse ("abcd" '(#\x #\q) nil t)
 283     (or #\q #\z (and #\a (or #\q #\x)))))
 284
 285 ;;;--------------------------------------------------------------------------
 286 ;;; Some tests with a simple recursive parser.
 287
 288 (defstruct (node
 289              (:predicate nodep)
 290              (:constructor make-node (left data right)))
 291   "Structure type for a simple binary tree."
 292   left data right)
 293
 294 (defun parse-tree (scanner)
 295   "Parse a textual representation into a simple binary tree.
 296
 297    The syntax is simple:
 298
 299         TREE ::= EMPTY | `(' TREE CHAR TREE `)'
 300
 301    There's an ambiguity in this syntax, at least if you have limited
 302    lookahead: suppose you've just parsed the opening `(' of a TREE, and you
 303    see another `(' -- is it the start of the non-empty left sub-TREE, or is
 304    it the CHAR following an empty left sub-TREE?  We opt for the first choice
 305    always."
 306
 307   ;; This came from another project, although it isn't actually used there.
 308   ;; It exposed the weakness in an earlier design which prompted the addition
 309   ;; of the CONSUMEDP flags to the parser protocol.
 310
 311   (with-parser-context (character-scanner-context :scanner scanner)
 312     (labels ((tree ()
 313                (parse (or (seq (#\(
 314                                 (left (tree))
 315                                 (data :any)
 316                                 (right (tree))
 317                                 #\))
 318                             (make-node left data right))
 319                           (values nil t nil)))))
 320       (parse (seq ((tree (tree)) :eof)
 321                tree)))))
 322
 323 (defun parse-tree-lookahead (scanner)
 324   "Parse a textual representation into a simple binary tree.
 325
 326    The syntax is simple, and, indeed, the grammar's the same as for
 327    `sod-parse-tree':
 328
 329         TREE ::= EMPTY | `(' TREE CHAR TREE `)'
 330
 331    But the rules are different.  Instead of resolving the `ambiguity' between
 332    TREE and CHAR when we find another `(' after the opening `(' of a TREE
 333    deterministically in favour of TREE as `parse-tree' does, we try that
 334    first, and backtrack if necessary."
 335
 336   ;; Bison can do this, but you have to persuade it to use the scary GLR
 337   ;; parser algorithm
 338
 339   (with-parser-context (character-scanner-context :scanner scanner)
 340     (labels ((tree ()
 341                (parse (or (peek (seq (#\(
 342                                       (left (tree))
 343                                       (data :any)
 344                                       (right (tree))
 345                                       #\))
 346                                   (make-node left data right)))
 347                           (values nil t nil)))))
 348       (parse (seq ((tree (tree)) :eof)
 349                tree)))))
 350
 351 (def-test-method test-simple-tree-parser ((test test-parser) :run nil)
 352   (assert-parse ("" nil t nil :scanner sc) (parse-tree sc))
 353   (assert-parse ("((a)b((c)d(e)))" t t t :scanner sc) (parse-tree sc))
 354   (assert-parse ("((a)b((c)d(e)))z" '(:eof) nil t :scanner sc)
 355     (parse-tree sc))
 356   (assert-parse ("((a)b((c)d(e))" '(#\)) nil t :scanner sc) (parse-tree sc))
 357   (assert-parse ("(([)*(]))" t t t :scanner sc) (parse-tree sc))
 358   (assert-parse ("((()-()))" '(#\)) nil t :scanner sc) (parse-tree sc))
 359   (assert-parse ("((()-()))" t t t :scanner sc) (parse-tree-lookahead sc)))
 360
 361 ;;;--------------------------------------------------------------------------
 362 ;;; Test expression parser.
 363
 364 (defparse token (:context (context character-parser-context) parser)
 365   (with-gensyms (value)
 366     (expand-parser-spec context
 367                         `(seq ((,value ,parser) :whitespace) ,value))))
 368
 369 (let ((add (binop "+" (x y 5) `(+ ,x ,y)))
 370       (sub (binop "-" (x y 5) `(- ,x ,y)))
 371       (mul (binop "*" (x y 7) `(* ,x ,y)))
 372       (div (binop "/" (x y 7) `(/ ,x ,y)))
 373       (eq (binop "=" (x y 3 :assoc nil) `(= ,x ,y)))
 374       (ne (binop "/=" (x y 3 :assoc nil) `(/= ,x ,y)))
 375       (lt (binop "<" (x y 3 :assoc nil) `(< ,x ,y)))
 376       (gt (binop ">" (x y 3 :assoc nil) `(> ,x ,y)))
 377       (and (binop "&" (x y 2) `(and ,x ,y)))
 378       (or (binop "|" (x y 1) `(or ,x ,y)))
 379       (expt (binop "**" (x y 8 :assoc :right) `(** ,x ,y)))
 380       (neg (preop "-" (x 9) `(- ,x)))
 381       (not (preop "!" (x 2) `(not ,x)))
 382       (fact (postop "!" (x 10) `(! ,x)))
 383       (lp (lparen #\))) (rp (rparen #\)))
 384       (lb (lparen #\])) (rb (rparen #\])))
 385   (defun test-parse-expr (string)
 386     (with-parser-context (string-parser :string string)
 387       (parse (seq (:whitespace
 388                    (value (expr (:nestedp nestedp)
 389                             (token (many (a 0 (+ (* a 10) it) :min 1)
 390                                      (filter digit-char-p)))
 391                             (token (or (seq ("**") expt)
 392                                        (seq ("/=") ne)
 393                                        (seq (#\+) add)
 394                                        (seq (#\-) sub)
 395                                        (seq (#\*) mul)
 396                                        (seq (#\/) div)
 397                                        (seq (#\=) eq)
 398                                        (seq (#\<) lt)
 399                                        (seq (#\>) gt)
 400                                        (seq (#\&) and)
 401                                        (seq (#\|) or)))
 402                             (token (or (seq (#\() lp)
 403                                        (seq (#\[) lb)
 404                                        (seq (#\-) neg)
 405                                        (seq (#\!) not)))
 406                             (token (or (seq (#\!) fact)
 407                                        (when nestedp
 408                                          (or (seq (#\)) rp)
 409                                              (seq (#\]) rb)))))))
 410                    (next (or :any (t :eof))))
 411                (cons value next))))))
 412
 413 (defun assert-expr-parse (string value winp consumedp)
 414   (multiple-value-bind (v w c) (test-parse-expr string)
 415     (flet ((message (what)
 416              (format nil "expression ~S; ~A" string what)))
 417       (cond (winp (assert-true w (message "winp"))
 418                   (assert-equal v value (message "value")))
 419             (t (assert-false w (message "winp"))
 420                (assert-equal v value (message "expected"))))
 421       (assert-eql c consumedp (message "consumedp")))))
 422
 423 (def-test-method test-expression-parser ((test test-parser) :run nil)
 424   (assert-expr-parse "1 + 2 + 3" '((+ (+ 1 2) 3) . :eof) t t)
 425   (assert-expr-parse "1 + 2 * 3" '((+ 1 (* 2 3)) . :eof) t t)
 426   (assert-expr-parse "1 * 2 + 3" '((+ (* 1 2) 3) . :eof) t t)
 427   (assert-expr-parse "(1 + 2) * 3" '((* (+ 1 2) 3) . :eof) t t)
 428   (assert-expr-parse "1 ** 2 ** 3" '((** 1 (** 2 3)) . :eof) t t)
 429   (assert-expr-parse "1 + 2) * 3" '((+ 1 2) . #\)) t t)
 430   (assert-expr-parse "1 + 2 * 3" '((+ 1 (* 2 3)) . :eof) t t)
 431   (assert-expr-parse "! 1 + 2 = 3 | 6 - 3 /= 12/6"
 432                      '((or (not (= (+ 1 2) 3))
 433                            (/= (- 6 3) (/ 12 6)))
 434                        . :eof)
 435                      t t)
 436   (assert-expr-parse "! 1 > 2 & ! 4 < 6 | 3 < 4 & 9 > 10"
 437                      '((or (and (not (> 1 2)) (not (< 4 6)))
 438                            (and (< 3 4) (> 9 10)))
 439                        . :eof)
 440                      t t)
 441
 442   (assert-condition 'simple-error (test-parse-expr "(1 + 2"))
 443   (assert-condition 'simple-error (test-parse-expr "(1 + 2]"))
 444   (assert-condition 'simple-error (test-parse-expr "1 < 2 < 3")))
 445
 446 ;;;----- That's all, folks --------------------------------------------------