+++ /dev/null
-;; ---------------------------------------------------------------------- ;;
-;; FICHIER : lalr.scm ;;
-;; DATE DE CREATION : Mon Jan 22 15:42:32 1996 ;;
-;; DERNIERE MODIFICATION : Mon Jun 3 10:24:43 1996 ;;
-;; ---------------------------------------------------------------------- ;;
-;; Copyright (C) 1984, 1989, 1990 Free Software Foundation, Inc. ;;
-;; (for the Bison source code translated in Scheme) ;;
-;; Copyright (C) 1996 Dominique Boucher ;;
-;; (for the translation in Scheme) ;;
-;; ---------------------------------------------------------------------- ;;
-;; An efficient Scheme LALR(1) Parser Generator -- lalr.scm ;;
-;; ---------------------------------------------------------------------- ;;
-;; This file contains yet another LALR(1) parser generator written in ;;
-;; Scheme. In contrast to other such parser generators, this one ;;
-;; implements a more efficient algorithm for computing the lookahead sets.;;
-;; The algorithm is the same as used in Bison (GNU yacc) and is described ;;
-;; in the following paper: ;;
-;; ;;
-;; "Efficient Computation of LALR(1) Look-Ahead Set", F. DeRemer and ;;
-;; T. Pennello, TOPLAS, vol. 4, no. 4, october 1982. ;;
-;; ;;
-;; As a consequence, it is not written in a fully functional style. ;;
-;; The program has been successfully tested on several Scheme ;;
-;; interpreters and compilers, including scm4d3, Gambit v2.2, and ;;
-;; MIT-Scheme 7.2.0 (microcode 11.127, runtime 14.160). ;;
-;; ---------------------------------------------------------------------- ;;
-;; HOW TO USE THE PROGRAM ;;
-;; ;;
-;; To generate a parser for a given grammar, the latter must be first ;;
-;; written down in scheme. The next section will describe the syntax ;;
-;; of the grammar. Now suppose your grammar is defined like this: ;;
-;; ;;
-;; (define my-grammar { grammar }) ;;
-;; ;;
-;; All you need to do is evaluate the expression: ;;
-;; ;;
-;; (gen-lalr1 my-grammar "file" [prefix]) ;;
-;; ;;
-;; where "file" is the name of the file (a string) that will contain the ;;
-;; tables for LR-parsing. The last argument must be supplied if you want ;;
-;; multiple parsers coexist in the same application. It must be a symbol, ;;
-;; otherwise it will be ignored. ;;
-;; ;;
-;; To run the parser, you must first load the LR parsing driver(also part ;;
-;; of this distribution): ;;
-;; ;;
-;; (load "lr-dvr.scm") ;;
-;; ;;
-;; The interface to the generated parser will be the function ;;
-;; ;;
-;; ([prefix-]parse lexer errorp) ;;
-;; ;;
-;; where lexer is the name of the scanner feeding the parser with pairs ;;
-;; (token . lval) and errorp is the name of a user-defined error ;;
-;; function (the standard error function can be used as well). ;;
-;; ;;
-;; ;;
-;; Here are some notes about the lexer and the error function: ;;
-;; ;;
-;; - the tokens (which are the first components of the pairs returned ;;
-;; by the lexer) must agree with the tokens defined in the grammar. ;;
-;; ;;
-;; - when the lexer wants to signal the end of the input, it must ;;
-;; return the pair '(0) each time it's invoked. ;;
-;; ;;
-;; - the error function must accept two parameters (the standard error ;;
-;; function accepts a variable number of parameters, so it accepts ;;
-;; two). ;;
-;; ;;
-;; ---------------------------------------------------------------------- ;;
-;; THE GRAMMAR FORMAT ;;
-;; ;;
-;; The grammar is specified by first giving the list of terminals and the ;;
-;; list of non-terminal definitions. Each non-terminal definition ;;
-;; is a list where the first element is the non-terminal and the other ;;
-;; elements are the right-hand sides (lists of grammar symbols). In ;;
-;; addition to this, each rhs can be followed by a semantic action. ;;
-;; By convention, use strings for tokens and atoms for non-terminals. ;;
-;; ;;
-;; For example, consider the following (yacc) grammar: ;;
-;; ;;
-;; e : e '+' t ;;
-;; | t ;;
-;; ; ;;
-;; ;;
-;; t : t '*' f ;;
-;; | f ;;
-;; ; ;;
-;; ;;
-;; f : ID ;;
-;; ; ;;
-;; ;;
-;; The same grammar, written for the scheme parser generator, would look ;;
-;; like this (with semantic actions) ;;
-;; ;;
-;; (define my-grammar ;;
-;; '( ;;
-;; ; Terminal symbols ;;
-;; ID ADD MULT ;;
-;; ; Productions ;;
-;; (e (e ADD t) : (+ $1 $3) ;;
-;; (t) : $1 ;;
-;; ) ;;
-;; (t (t MULT f) : (* $1 $3) ;;
-;; (f) : $1 ;;
-;; ) ;;
-;; (f (ID) : $1) ;;
-;; )) ;;
-;; ;;
-;; In semantic actions, the symbol $<n> refers to the synthesized ;;
-;; attribute value of the nth symbol in the production. The value ;;
-;; associated with the non-terminal on the left is the result of ;;
-;; evaluating the semantic action (it defaults to #f). ;;
-;; ;;
-;; If you evaluate ;;
-;; ;;
-;; (gen-lalr1 my-grammar "foo.scm" 'my) ;;
-;; ;;
-;; then the generated parser will be named 'my-parser'. ;;
-;; ;;
-;; NOTE ON CONFLICT RESOLUTION ;;
-;; ;;
-;; Conflicts in the grammar are handled in a conventional way. ;;
-;; Shift/Reduce conflicts are resolved by shifting, and Reduce/Reduce ;;
-;; conflicts are resolved by choosing the rule listed first in the ;;
-;; grammar definition. ;;
-;; ;;
-;; You can print the states of the generated parser by evaluating ;;
-;; `(print-states)'. The format of the output is similar to the one ;;
-;; produced by bison when given the -v command-line option. ;;
-;; ---------------------------------------------------------------------- ;;
-;; lalr.scm 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 2, or (at your option) ;;
-;; any later version. ;;
-;; ;;
-;; lalr.scm 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 lalr.scm; see the file COPYING. If not, write to ;;
-;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. ;;
-;; ;;
-;; Dominique Boucher -- Universite de Montreal ;;
-;; ;;
-;; Send questions, comments or suggestions to boucherd@iro.umontreal.ca ;;
-;; ---------------------------------------------------------------------- ;;
-
-;; 1998/08/16: Tanaka Akira <akr@jaist.ac.jp> transplants generating code from Scheme to Emacs-Lisp.
-
-;;; ---------- SYSTEM DEPENDENT SECTION -----------------
-
-;; -------- SCM
-(begin
- (defmacro def-macro (args body)
- `(defmacro ,(car args) ,(cdr args) ,body))
-
- (def-macro (BITS-PER-WORD) 24)
- (def-macro (logical-or x . y) `(logior ,x ,@y))
- )
-
-;; -------- MIT-Scheme
-'(begin
- (declare (usual-integrations))
-
- (define-macro (def-macro form . body)
- `(DEFINE-MACRO ,form (LET () ,@body)))
-
- (def-macro (BITS-PER-WORD) 24)
- (def-macro (logical-or x . y) `(fix:or ,x ,@y))
- )
-
-;; -------- Gambit
-'(begin
-
- (declare
- (standard-bindings)
- (fixnum)
- (block)
- (not safe))
-
- (define-macro (def-macro form . body)
- `(DEFINE-MACRO ,form (LET () ,@body)))
-
- (def-macro (BITS-PER-WORD) 28)
- (def-macro (logical-or x . y) `(,(string->symbol "##logior") ,x ,@y))
- )
-
-;; -------- Bigloo
-'(begin
-
- (define-macro (def-macro form . body)
- `(DEFINE-MACRO ,form (LET () ,@body)))
- (def-macro (BITS-PER-WORD) 16)
- (def-macro (logical-or x . y) `(bit-or ,x ,@y))
- )
-
-;;; ---------- END OF SYSTEM DEPENDENT SECTION ------------
-
-;; - Macros pour la gestion des vecteurs de bits
-
-(def-macro (set-bit v b)
- `(let ((x (quotient ,b (BITS-PER-WORD)))
- (y (expt 2 (remainder ,b (BITS-PER-WORD)))))
- (vector-set! ,v x (logical-or (vector-ref ,v x) y))))
-
-(def-macro (bit-union v1 v2 n)
- `(do ((i 0 (+ i 1)))
- ((= i ,n))
- (vector-set! ,v1 i (logical-or (vector-ref ,v1 i)
- (vector-ref ,v2 i)))))
-
-;; - Macro pour les structures de donnees
-
-(def-macro (new-core) `(make-vector 4 0))
-(def-macro (set-core-number! c n) `(vector-set! ,c 0 ,n))
-(def-macro (set-core-acc-sym! c s) `(vector-set! ,c 1 ,s))
-(def-macro (set-core-nitems! c n) `(vector-set! ,c 2 ,n))
-(def-macro (set-core-items! c i) `(vector-set! ,c 3 ,i))
-(def-macro (core-number c) `(vector-ref ,c 0))
-(def-macro (core-acc-sym c) `(vector-ref ,c 1))
-(def-macro (core-nitems c) `(vector-ref ,c 2))
-(def-macro (core-items c) `(vector-ref ,c 3))
-
-(def-macro (new-shift) `(make-vector 3 0))
-(def-macro (set-shift-number! c x) `(vector-set! ,c 0 ,x))
-(def-macro (set-shift-nshifts! c x) `(vector-set! ,c 1 ,x))
-(def-macro (set-shift-shifts! c x) `(vector-set! ,c 2 ,x))
-(def-macro (shift-number s) `(vector-ref ,s 0))
-(def-macro (shift-nshifts s) `(vector-ref ,s 1))
-(def-macro (shift-shifts s) `(vector-ref ,s 2))
-
-(def-macro (new-red) `(make-vector 3 0))
-(def-macro (set-red-number! c x) `(vector-set! ,c 0 ,x))
-(def-macro (set-red-nreds! c x) `(vector-set! ,c 1 ,x))
-(def-macro (set-red-rules! c x) `(vector-set! ,c 2 ,x))
-(def-macro (red-number c) `(vector-ref ,c 0))
-(def-macro (red-nreds c) `(vector-ref ,c 1))
-(def-macro (red-rules c) `(vector-ref ,c 2))
-
-
-
-(def-macro (new-set nelem)
- `(make-vector ,nelem 0))
-
-
-(def-macro (vector-map f v)
- `(let ((vm-n (- (vector-length ,v) 1)))
- (let loop ((vm-low 0) (vm-high vm-n))
- (if (= vm-low vm-high)
- (vector-set! ,v vm-low (,f (vector-ref ,v vm-low) vm-low))
- (let ((vm-middle (quotient (+ vm-low vm-high) 2)))
- (loop vm-low vm-middle)
- (loop (+ vm-middle 1) vm-high))))))
-
-
-;; - Constantes
-(define STATE-TABLE-SIZE 1009)
-
-
-;; - Tableaux
-(define rrhs #f)
-(define rlhs #f)
-(define ritem #f)
-(define nullable #f)
-(define derives #f)
-(define fderives #f)
-(define firsts #f)
-(define kernel-base #f)
-(define kernel-end #f)
-(define shift-symbol #f)
-(define shift-set #f)
-(define red-set #f)
-(define state-table #f)
-(define acces-symbol #f)
-(define reduction-table #f)
-(define shift-table #f)
-(define consistent #f)
-(define lookaheads #f)
-(define LA #f)
-(define LAruleno #f)
-(define lookback #f)
-(define goto-map #f)
-(define from-state #f)
-(define to-state #f)
-(define includes #f)
-(define F #f)
-(define action-table #f)
-
-;; - Variables
-(define nitems #f)
-(define nrules #f)
-(define nvars #f)
-(define nterms #f)
-(define nsyms #f)
-(define nstates #f)
-(define first-state #f)
-(define last-state #f)
-(define final-state #f)
-(define first-shift #f)
-(define last-shift #f)
-(define first-reduction #f)
-(define last-reduction #f)
-(define nshifts #f)
-(define maxrhs #f)
-(define ngotos #f)
-(define token-set-size #f)
-
-(define (gen-larl1 gram output-file header footer . opt)
- (define (conv-rule-right rr)
- (if (null? rr)
- '()
- (cons (reverse (car rr))
- (cons (cadr rr)
- (cons (caddr rr)
- (conv-rule-right (cdddr rr)))))))
- (apply gen-lalr1
- (map
- (lambda (elt)
- (if (symbol? elt)
- elt
- (cons (car elt) (conv-rule-right (cdr elt)))))
- gram)
- output-file
- header
- footer
- opt))
-
-(define (gen-lalr1 gram output-file header footer . opt)
- (initialize-all)
- (rewrite-grammar
- gram
- (lambda (terms vars gram gram/actions)
- (set! the-terminals (list->vector terms))
- (set! the-nonterminals (list->vector vars))
- (set! nterms (length terms))
- (set! nvars (length vars))
- (set! nsyms (+ nterms nvars))
- (let ((no-of-rules (length gram/actions))
- (no-of-items (let loop ((l gram/actions) (count 0))
- (if (null? l)
- count
- (loop (cdr l) (+ count (length (caar l))))))))
- (pack-grammar no-of-rules no-of-items gram)
- (set-derives)
- (set-nullable)
- (generate-states)
- (lalr)
- (build-tables)
- (compact-action-table)
- (let* ((parser-name (if (and (pair? opt) (symbol? (car opt))) (car opt) #f))
- (prefix (if parser-name
- (string-append
- (symbol->string parser-name)
- ":")
- ""))
- (parser-prefix (if parser-name
- (string-append (symbol->string parser-name) "-")
- "")))
- (with-output-to-file output-file
- (lambda ()
- (display "; *** Header ***")
- (newline)
- (output-header header parser-prefix)
- (display "; *** Token Definitions ***")
- (newline)
- (output-token-defs terms prefix)
- (display "; *** Action Table ***")
- (newline)
- (output-action-table prefix)
- (display "; *** Goto Table ***")
- (newline)
- (output-goto-table prefix)
- (display "; *** Reduction Table ***")
- (newline)
- (output-reduction-table gram/actions prefix)
- (display "; *** Parser Definition ***")
- (newline)
- (output-parser-def parser-prefix prefix)
- (display "; *** Footer ***")
- (newline)
- (output-footer footer)
- )))))))
-
-
-(define (initialize-all)
- (set! rrhs #f)
- (set! rlhs #f)
- (set! ritem #f)
- (set! nullable #f)
- (set! derives #f)
- (set! fderives #f)
- (set! firsts #f)
- (set! kernel-base #f)
- (set! kernel-end #f)
- (set! shift-symbol #f)
- (set! shift-set #f)
- (set! red-set #f)
- (set! state-table (make-vector STATE-TABLE-SIZE '()))
- (set! acces-symbol #f)
- (set! reduction-table #f)
- (set! shift-table #f)
- (set! consistent #f)
- (set! lookaheads #f)
- (set! LA #f)
- (set! LAruleno #f)
- (set! lookback #f)
- (set! goto-map #f)
- (set! from-state #f)
- (set! to-state #f)
- (set! includes #f)
- (set! F #f)
- (set! action-table #f)
- (set! nstates #f)
- (set! first-state #f)
- (set! last-state #f)
- (set! final-state #f)
- (set! first-shift #f)
- (set! last-shift #f)
- (set! first-reduction #f)
- (set! last-reduction #f)
- (set! nshifts #f)
- (set! maxrhs #f)
- (set! ngotos #f)
- (set! token-set-size #f))
-
-
-(define (pack-grammar no-of-rules no-of-items gram)
- (set! nrules (+ no-of-rules 1))
- (set! nitems no-of-items)
- (set! rlhs (make-vector nrules #f))
- (set! rrhs (make-vector nrules #f))
- (set! ritem (make-vector (+ 1 nitems) #f))
-
- (let loop ((p gram) (item-no 0) (rule-no 1))
- (if (not (null? p))
- (let ((nt (caar p)))
- (let loop2 ((prods (cdar p)) (it-no2 item-no) (rl-no2 rule-no))
- (if (null? prods)
- (loop (cdr p) it-no2 rl-no2)
- (begin
- (vector-set! rlhs rl-no2 nt)
- (vector-set! rrhs rl-no2 it-no2)
- (let loop3 ((rhs (car prods)) (it-no3 it-no2))
- (if (null? rhs)
- (begin
- (vector-set! ritem it-no3 (- rl-no2))
- (loop2 (cdr prods) (+ it-no3 1) (+ rl-no2 1)))
- (begin
- (vector-set! ritem it-no3 (car rhs))
- (loop3 (cdr rhs) (+ it-no3 1))))))))))))
-
-
-;; Fonction set-derives
-;; --------------------
-(define (set-derives)
- (define delts (make-vector (+ nrules 1) 0))
- (define dset (make-vector nvars -1))
-
- (let loop ((i 1) (j 0)) ; i = 0
- (if (< i nrules)
- (let ((lhs (vector-ref rlhs i)))
- (if (>= lhs 0)
- (begin
- (vector-set! delts j (cons i (vector-ref dset lhs)))
- (vector-set! dset lhs j)
- (loop (+ i 1) (+ j 1)))
- (loop (+ i 1) j)))))
-
- (set! derives (make-vector nvars 0))
-
- (let loop ((i 0))
- (if (< i nvars)
- (let ((q (let loop2 ((j (vector-ref dset i)) (s '()))
- (if (< j 0)
- s
- (let ((x (vector-ref delts j)))
- (loop2 (cdr x) (cons (car x) s)))))))
- (vector-set! derives i q)
- (loop (+ i 1))))))
-
-
-
-(define (set-nullable)
- (set! nullable (make-vector nvars #f))
- (let ((squeue (make-vector nvars #f))
- (rcount (make-vector (+ nrules 1) 0))
- (rsets (make-vector nvars #f))
- (relts (make-vector (+ nitems nvars 1) #f)))
- (let loop ((r 0) (s2 0) (p 0))
- (let ((*r (vector-ref ritem r)))
- (if *r
- (if (< *r 0)
- (let ((symbol (vector-ref rlhs (- *r))))
- (if (and (>= symbol 0)
- (not (vector-ref nullable symbol)))
- (begin
- (vector-set! nullable symbol #t)
- (vector-set! squeue s2 symbol)
- (loop (+ r 1) (+ s2 1) p))))
- (let loop2 ((r1 r) (any-tokens #f))
- (let* ((symbol (vector-ref ritem r1)))
- (if (> symbol 0)
- (loop2 (+ r1 1) (or any-tokens (>= symbol nvars)))
- (if (not any-tokens)
- (let ((ruleno (- symbol)))
- (let loop3 ((r2 r) (p2 p))
- (let ((symbol (vector-ref ritem r2)))
- (if (> symbol 0)
- (begin
- (vector-set! rcount ruleno
- (+ (vector-ref rcount ruleno) 1))
- (vector-set! relts p2
- (cons (vector-ref rsets symbol)
- ruleno))
- (vector-set! rsets symbol p2)
- (loop3 (+ r2 1) (+ p2 1)))
- (loop (+ r2 1) s2 p2)))))
- (loop (+ r1 1) s2 p))))))
- (let loop ((s1 0) (s3 s2))
- (if (< s1 s3)
- (let loop2 ((p (vector-ref rsets (vector-ref squeue s1))) (s4 s3))
- (if p
- (let* ((x (vector-ref relts p))
- (ruleno (cdr x))
- (y (- (vector-ref rcount ruleno) 1)))
- (vector-set! rcount ruleno y)
- (if (= y 0)
- (let ((symbol (vector-ref rlhs ruleno)))
- (if (and (>= symbol 0)
- (not (vector-ref nullable symbol)))
- (begin
- (vector-set! nullable symbol #t)
- (vector-set! squeue s4 symbol)
- (loop2 (car x) (+ s4 1)))
- (loop2 (car x) s4)))
- (loop2 (car x) s4))))
- (loop (+ s1 1) s4)))))))))
-
-
-
-; Fonction set-firsts qui calcule un tableau de taille
-; nvars et qui donne, pour chaque non-terminal X, une liste des
-; non-terminaux pouvant apparaitre au debut d'une derivation a
-; partir de X.
-
-(define (set-firsts)
- (set! firsts (make-vector nvars '()))
-
- ;; -- initialization
- (let loop ((i 0))
- (if (< i nvars)
- (let loop2 ((sp (vector-ref derives i)))
- (if (null? sp)
- (loop (+ i 1))
- (let ((sym (vector-ref ritem (vector-ref rrhs (car sp)))))
- (if (< -1 sym nvars)
- (vector-set! firsts i (sinsert sym (vector-ref firsts i))))
- (loop2 (cdr sp)))))))
-
- ;; -- reflexive and transitive closure
- (let loop ((continue #t))
- (if continue
- (let loop2 ((i 0) (cont #f))
- (if (>= i nvars)
- (loop cont)
- (let* ((x (vector-ref firsts i))
- (y (let loop3 ((l x) (z x))
- (if (null? l)
- z
- (loop3 (cdr l)
- (sunion (vector-ref firsts (car l)) z))))))
- (if (equal? x y)
- (loop2 (+ i 1) cont)
- (begin
- (vector-set! firsts i y)
- (loop2 (+ i 1) #t))))))))
-
- (let loop ((i 0))
- (if (< i nvars)
- (begin
- (vector-set! firsts i (sinsert i (vector-ref firsts i)))
- (loop (+ i 1))))))
-
-
-
-
-; Fonction set-fderives qui calcule un tableau de taille
-; nvars et qui donne, pour chaque non-terminal, une liste des regles pouvant
-; etre derivees a partir de ce non-terminal. (se sert de firsts)
-
-(define (set-fderives)
- (set! fderives (make-vector nvars #f))
-
- (set-firsts)
-
- (let loop ((i 0))
- (if (< i nvars)
- (let ((x (let loop2 ((l (vector-ref firsts i)) (fd '()))
- (if (null? l)
- fd
- (loop2 (cdr l)
- (sunion (vector-ref derives (car l)) fd))))))
- (vector-set! fderives i x)
- (loop (+ i 1))))))
-
-
-; Fonction calculant la fermeture d'un ensemble d'items LR0
-; ou core est une liste d'items
-
-(define (closure core)
- ;; Initialization
- (define ruleset (make-vector nrules #f))
-
- (let loop ((csp core))
- (if (not (null? csp))
- (let ((sym (vector-ref ritem (car csp))))
- (if (< -1 sym nvars)
- (let loop2 ((dsp (vector-ref fderives sym)))
- (if (not (null? dsp))
- (begin
- (vector-set! ruleset (car dsp) #t)
- (loop2 (cdr dsp))))))
- (loop (cdr csp)))))
-
- (let loop ((ruleno 1) (csp core) (itemsetv '())) ; ruleno = 0
- (if (< ruleno nrules)
- (if (vector-ref ruleset ruleno)
- (let ((itemno (vector-ref rrhs ruleno)))
- (let loop2 ((c csp) (itemsetv2 itemsetv))
- (if (and (pair? c)
- (< (car c) itemno))
- (loop2 (cdr c) (cons (car c) itemsetv2))
- (loop (+ ruleno 1) c (cons itemno itemsetv2)))))
- (loop (+ ruleno 1) csp itemsetv))
- (let loop2 ((c csp) (itemsetv2 itemsetv))
- (if (pair? c)
- (loop2 (cdr c) (cons (car c) itemsetv2))
- (reverse itemsetv2))))))
-
-
-
-(define (allocate-item-sets)
- (set! kernel-base (make-vector nsyms 0))
- (set! kernel-end (make-vector nsyms #f)))
-
-
-(define (allocate-storage)
- (allocate-item-sets)
- (set! red-set (make-vector (+ nrules 1) 0)))
-
-;; --
-
-
-(define (initialize-states)
- (let ((p (new-core)))
- (set-core-number! p 0)
- (set-core-acc-sym! p #f)
- (set-core-nitems! p 1)
- (set-core-items! p '(0))
-
- (set! first-state (list p))
- (set! last-state first-state)
- (set! nstates 1)))
-
-
-
-(define (generate-states)
- (allocate-storage)
- (set-fderives)
- (initialize-states)
- (let loop ((this-state first-state))
- (if (pair? this-state)
- (let* ((x (car this-state))
- (is (closure (core-items x))))
- (save-reductions x is)
- (new-itemsets is)
- (append-states)
- (if (> nshifts 0)
- (save-shifts x))
- (loop (cdr this-state))))))
-
-
-;; Fonction calculant les symboles sur lesquels il faut "shifter"
-;; et regroupe les items en fonction de ces symboles
-
-(define (new-itemsets itemset)
- ;; - Initialization
- (set! shift-symbol '())
- (let loop ((i 0))
- (if (< i nsyms)
- (begin
- (vector-set! kernel-end i '())
- (loop (+ i 1)))))
-
- (let loop ((isp itemset))
- (if (pair? isp)
- (let* ((i (car isp))
- (sym (vector-ref ritem i)))
- (if (>= sym 0)
- (begin
- (set! shift-symbol (sinsert sym shift-symbol))
- (let ((x (vector-ref kernel-end sym)))
- (if (null? x)
- (begin
- (vector-set! kernel-base sym (cons (+ i 1) x))
- (vector-set! kernel-end sym (vector-ref kernel-base sym)))
- (begin
- (set-cdr! x (list (+ i 1)))
- (vector-set! kernel-end sym (cdr x)))))))
- (loop (cdr isp)))))
-
- (set! nshifts (length shift-symbol)))
-
-
-
-(define (get-state sym)
- (let* ((isp (vector-ref kernel-base sym))
- (n (length isp))
- (key (let loop ((isp1 isp) (k 0))
- (if (null? isp1)
- (modulo k STATE-TABLE-SIZE)
- (loop (cdr isp1) (+ k (car isp1))))))
- (sp (vector-ref state-table key)))
- (if (null? sp)
- (let ((x (new-state sym)))
- (vector-set! state-table key (list x))
- (core-number x))
- (let loop ((sp1 sp))
- (if (and (= n (core-nitems (car sp1)))
- (let loop2 ((i1 isp) (t (core-items (car sp1))))
- (if (and (pair? i1)
- (= (car i1)
- (car t)))
- (loop2 (cdr i1) (cdr t))
- (null? i1))))
- (core-number (car sp1))
- (if (null? (cdr sp1))
- (let ((x (new-state sym)))
- (set-cdr! sp1 (list x))
- (core-number x))
- (loop (cdr sp1))))))))
-
-
-(define (new-state sym)
- (let* ((isp (vector-ref kernel-base sym))
- (n (length isp))
- (p (new-core)))
- (set-core-number! p nstates)
- (set-core-acc-sym! p sym)
- (if (= sym nvars) (set! final-state nstates))
- (set-core-nitems! p n)
- (set-core-items! p isp)
- (set-cdr! last-state (list p))
- (set! last-state (cdr last-state))
- (set! nstates (+ nstates 1))
- p))
-
-
-;; --
-
-(define (append-states)
- (set! shift-set
- (let loop ((l (reverse shift-symbol)))
- (if (null? l)
- '()
- (cons (get-state (car l)) (loop (cdr l)))))))
-
-;; --
-
-(define (save-shifts core)
- (let ((p (new-shift)))
- (set-shift-number! p (core-number core))
- (set-shift-nshifts! p nshifts)
- (set-shift-shifts! p shift-set)
- (if last-shift
- (begin
- (set-cdr! last-shift (list p))
- (set! last-shift (cdr last-shift)))
- (begin
- (set! first-shift (list p))
- (set! last-shift first-shift)))))
-
-(define (save-reductions core itemset)
- (let ((rs (let loop ((l itemset))
- (if (null? l)
- '()
- (let ((item (vector-ref ritem (car l))))
- (if (< item 0)
- (cons (- item) (loop (cdr l)))
- (loop (cdr l))))))))
- (if (pair? rs)
- (let ((p (new-red)))
- (set-red-number! p (core-number core))
- (set-red-nreds! p (length rs))
- (set-red-rules! p rs)
- (if last-reduction
- (begin
- (set-cdr! last-reduction (list p))
- (set! last-reduction (cdr last-reduction)))
- (begin
- (set! first-reduction (list p))
- (set! last-reduction first-reduction)))))))
-
-
-;; --
-
-(define (lalr)
- (set! token-set-size (+ 1 (quotient nterms (BITS-PER-WORD))))
- (set-accessing-symbol)
- (set-shift-table)
- (set-reduction-table)
- (set-max-rhs)
- (initialize-LA)
- (set-goto-map)
- (initialize-F)
- (build-relations)
- (digraph includes)
- (compute-lookaheads))
-
-(define (set-accessing-symbol)
- (set! acces-symbol (make-vector nstates #f))
- (let loop ((l first-state))
- (if (pair? l)
- (let ((x (car l)))
- (vector-set! acces-symbol (core-number x) (core-acc-sym x))
- (loop (cdr l))))))
-
-(define (set-shift-table)
- (set! shift-table (make-vector nstates #f))
- (let loop ((l first-shift))
- (if (pair? l)
- (let ((x (car l)))
- (vector-set! shift-table (shift-number x) x)
- (loop (cdr l))))))
-
-(define (set-reduction-table)
- (set! reduction-table (make-vector nstates #f))
- (let loop ((l first-reduction))
- (if (pair? l)
- (let ((x (car l)))
- (vector-set! reduction-table (red-number x) x)
- (loop (cdr l))))))
-
-(define (set-max-rhs)
- (let loop ((p 0) (curmax 0) (length 0))
- (let ((x (vector-ref ritem p)))
- (if x
- (if (>= x 0)
- (loop (+ p 1) curmax (+ length 1))
- (loop (+ p 1) (max curmax length) 0))
- (set! maxrhs curmax)))))
-
-(define (initialize-LA)
- (define (last l)
- (if (null? (cdr l))
- (car l)
- (last (cdr l))))
-
- (set! consistent (make-vector nstates #f))
- (set! lookaheads (make-vector (+ nstates 1) #f))
-
- (let loop ((count 0) (i 0))
- (if (< i nstates)
- (begin
- (vector-set! lookaheads i count)
- (let ((rp (vector-ref reduction-table i))
- (sp (vector-ref shift-table i)))
- (if (and rp
- (or (> (red-nreds rp) 1)
- (and sp
- (not
- (< (vector-ref acces-symbol
- (last (shift-shifts sp)))
- nvars)))))
- (loop (+ count (red-nreds rp)) (+ i 1))
- (begin
- (vector-set! consistent i #t)
- (loop count (+ i 1))))))
-
- (begin
- (vector-set! lookaheads nstates count)
- (let ((c (max count 1)))
- (set! LA (make-vector c #f))
- (do ((j 0 (+ j 1))) ((= j c)) (vector-set! LA j (new-set token-set-size)))
- (set! LAruleno (make-vector c -1))
- (set! lookback (make-vector c #f)))
- (let loop ((i 0) (np 0))
- (if (< i nstates)
- (if (vector-ref consistent i)
- (loop (+ i 1) np)
- (let ((rp (vector-ref reduction-table i)))
- (if rp
- (let loop2 ((j (red-rules rp)) (np2 np))
- (if (null? j)
- (loop (+ i 1) np2)
- (begin
- (vector-set! LAruleno np2 (car j))
- (loop2 (cdr j) (+ np2 1)))))
- (loop (+ i 1) np))))))))))
-
-
-(define (set-goto-map)
- (set! goto-map (make-vector (+ nvars 1) 0))
- (let ((temp-map (make-vector (+ nvars 1) 0)))
- (let loop ((ng 0) (sp first-shift))
- (if (pair? sp)
- (let loop2 ((i (reverse (shift-shifts (car sp)))) (ng2 ng))
- (if (pair? i)
- (let ((symbol (vector-ref acces-symbol (car i))))
- (if (< symbol nvars)
- (begin
- (vector-set! goto-map symbol
- (+ 1 (vector-ref goto-map symbol)))
- (loop2 (cdr i) (+ ng2 1)))
- (loop2 (cdr i) ng2)))
- (loop ng2 (cdr sp))))
-
- (let loop ((k 0) (i 0))
- (if (< i nvars)
- (begin
- (vector-set! temp-map i k)
- (loop (+ k (vector-ref goto-map i)) (+ i 1)))
-
- (begin
- (do ((i 0 (+ i 1)))
- ((>= i nvars))
- (vector-set! goto-map i (vector-ref temp-map i)))
-
- (set! ngotos ng)
- (vector-set! goto-map nvars ngotos)
- (vector-set! temp-map nvars ngotos)
- (set! from-state (make-vector ngotos #f))
- (set! to-state (make-vector ngotos #f))
-
- (do ((sp first-shift (cdr sp)))
- ((null? sp))
- (let* ((x (car sp))
- (state1 (shift-number x)))
- (do ((i (shift-shifts x) (cdr i)))
- ((null? i))
- (let* ((state2 (car i))
- (symbol (vector-ref acces-symbol state2)))
- (if (< symbol nvars)
- (let ((k (vector-ref temp-map symbol)))
- (vector-set! temp-map symbol (+ k 1))
- (vector-set! from-state k state1)
- (vector-set! to-state k state2))))))))))))))
-
-
-(define (map-goto state symbol)
- (let loop ((low (vector-ref goto-map symbol))
- (high (- (vector-ref goto-map (+ symbol 1)) 1)))
- (if (> low high)
- (begin
- (display (list "Error in map-goto" state symbol)) (newline)
- 0)
- (let* ((middle (quotient (+ low high) 2))
- (s (vector-ref from-state middle)))
- (cond
- ((= s state)
- middle)
- ((< s state)
- (loop (+ middle 1) high))
- (else
- (loop low (- middle 1))))))))
-
-
-(define (initialize-F)
- (set! F (make-vector ngotos #f))
- (do ((i 0 (+ i 1))) ((= i ngotos)) (vector-set! F i (new-set token-set-size)))
-
- (let ((reads (make-vector ngotos #f)))
-
- (let loop ((i 0) (rowp 0))
- (if (< i ngotos)
- (let* ((rowf (vector-ref F rowp))
- (stateno (vector-ref to-state i))
- (sp (vector-ref shift-table stateno)))
- (if sp
- (let loop2 ((j (shift-shifts sp)) (edges '()))
- (if (pair? j)
- (let ((symbol (vector-ref acces-symbol (car j))))
- (if (< symbol nvars)
- (if (vector-ref nullable symbol)
- (loop2 (cdr j) (cons (map-goto stateno symbol)
- edges))
- (loop2 (cdr j) edges))
- (begin
- (set-bit rowf (- symbol nvars))
- (loop2 (cdr j) edges))))
- (if (pair? edges)
- (vector-set! reads i (reverse edges))))))
- (loop (+ i 1) (+ rowp 1)))))
- (digraph reads)))
-
-(define (add-lookback-edge stateno ruleno gotono)
- (let ((k (vector-ref lookaheads (+ stateno 1))))
- (let loop ((found #f) (i (vector-ref lookaheads stateno)))
- (if (and (not found) (< i k))
- (if (= (vector-ref LAruleno i) ruleno)
- (loop #t i)
- (loop found (+ i 1)))
-
- (if (not found)
- (begin (display "Error in add-lookback-edge : ")
- (display (list stateno ruleno gotono)) (newline))
- (vector-set! lookback i
- (cons gotono (vector-ref lookback i))))))))
-
-
-(define (transpose r-arg n)
- (let ((new-end (make-vector n #f))
- (new-R (make-vector n #f)))
- (do ((i 0 (+ i 1)))
- ((= i n))
- (let ((x (list 'bidon)))
- (vector-set! new-R i x)
- (vector-set! new-end i x)))
- (do ((i 0 (+ i 1)))
- ((= i n))
- (let ((sp (vector-ref r-arg i)))
- (if (pair? sp)
- (let loop ((sp2 sp))
- (if (pair? sp2)
- (let* ((x (car sp2))
- (y (vector-ref new-end x)))
- (set-cdr! y (cons i (cdr y)))
- (vector-set! new-end x (cdr y))
- (loop (cdr sp2))))))))
- (do ((i 0 (+ i 1)))
- ((= i n))
- (vector-set! new-R i (cdr (vector-ref new-R i))))
-
- new-R))
-
-
-
-(define (build-relations)
-
- (define (get-state stateno symbol)
- (let loop ((j (shift-shifts (vector-ref shift-table stateno)))
- (stno stateno))
- (if (null? j)
- stno
- (let ((st2 (car j)))
- (if (= (vector-ref acces-symbol st2) symbol)
- st2
- (loop (cdr j) st2))))))
-
- (set! includes (make-vector ngotos #f))
- (do ((i 0 (+ i 1)))
- ((= i ngotos))
- (let ((state1 (vector-ref from-state i))
- (symbol1 (vector-ref acces-symbol (vector-ref to-state i))))
- (let loop ((rulep (vector-ref derives symbol1))
- (edges '()))
- (if (pair? rulep)
- (let ((*rulep (car rulep)))
- (let loop2 ((rp (vector-ref rrhs *rulep))
- (stateno state1)
- (states (list state1)))
- (let ((*rp (vector-ref ritem rp)))
- (if (> *rp 0)
- (let ((st (get-state stateno *rp)))
- (loop2 (+ rp 1) st (cons st states)))
- (begin
-
- (if (not (vector-ref consistent stateno))
- (add-lookback-edge stateno *rulep i))
-
- (let loop2 ((done #f)
- (stp (cdr states))
- (rp2 (- rp 1))
- (edgp edges))
- (if (not done)
- (let ((*rp (vector-ref ritem rp2)))
- (if (< -1 *rp nvars)
- (loop2 (not (vector-ref nullable *rp))
- (cdr stp)
- (- rp2 1)
- (cons (map-goto (car stp) *rp) edgp))
- (loop2 #t stp rp2 edgp)))
-
- (loop (cdr rulep) edgp))))))))
- (vector-set! includes i edges)))))
- (set! includes (transpose includes ngotos)))
-
-
-
-(define (compute-lookaheads)
- (let ((n (vector-ref lookaheads nstates)))
- (let loop ((i 0))
- (if (< i n)
- (let loop2 ((sp (vector-ref lookback i)))
- (if (pair? sp)
- (let ((LA-i (vector-ref LA i))
- (F-j (vector-ref F (car sp))))
- (bit-union LA-i F-j token-set-size)
- (loop2 (cdr sp)))
- (loop (+ i 1))))))))
-
-
-
-(define (digraph relation)
- (define infinity (+ ngotos 2))
- (define INDEX (make-vector (+ ngotos 1) 0))
- (define VERTICES (make-vector (+ ngotos 1) 0))
- (define top 0)
- (define R relation)
-
- (define (traverse i)
- (set! top (+ 1 top))
- (vector-set! VERTICES top i)
- (let ((height top))
- (vector-set! INDEX i height)
- (let ((rp (vector-ref R i)))
- (if (pair? rp)
- (let loop ((rp2 rp))
- (if (pair? rp2)
- (let ((j (car rp2)))
- (if (= 0 (vector-ref INDEX j))
- (traverse j))
- (if (> (vector-ref INDEX i)
- (vector-ref INDEX j))
- (vector-set! INDEX i (vector-ref INDEX j)))
- (let ((F-i (vector-ref F i))
- (F-j (vector-ref F j)))
- (bit-union F-i F-j token-set-size))
- (loop (cdr rp2))))))
- (if (= (vector-ref INDEX i) height)
- (let loop ()
- (let ((j (vector-ref VERTICES top)))
- (set! top (- top 1))
- (vector-set! INDEX j infinity)
- (if (not (= i j))
- (begin
- (bit-union (vector-ref F i)
- (vector-ref F j)
- token-set-size)
- (loop)))))))))
-
- (let loop ((i 0))
- (if (< i ngotos)
- (begin
- (if (and (= 0 (vector-ref INDEX i))
- (pair? (vector-ref R i)))
- (traverse i))
- (loop (+ i 1))))))
-
-
-;; --
-
-(define (build-tables)
- (define (add-action St Sym Act)
- (let* ((x (vector-ref ACTION-TABLE St))
- (y (assv Sym x)))
- (if y
- (if (not (= Act (cdr y)))
- ;; -- there is a conflict
- (begin
- (if (and (<= (cdr y) 0)
- (<= Act 0))
- (begin
- (display "%% Reduce/Reduce conflict ")
- (display "(reduce ") (display (- Act))
- (display ", reduce ") (display (- (cdr y)))
- (display ") on ") (print-symbol (+ Sym nvars))
- (display " in state ") (display St)
- (newline)
- (set-cdr! y (max (cdr y) Act)))
- (begin
- (display "%% Shift/Reduce conflict ")
- (display "(shift ") (display Act)
- (display ", reduce ") (display (- (cdr y)))
- (display ") on ") (print-symbol (+ Sym nvars))
- (display " in state ") (display St)
- (newline)
- (set-cdr! y Act)))))
- (vector-set! ACTION-TABLE St
- (cons (cons Sym Act) x)))))
-
- (set! action-table (make-vector nstates '()))
-
- (do ((i 0 (+ i 1))) ; i = state
- ((= i nstates))
- (let ((red (vector-ref reduction-table i)))
- (if (and red (>= (red-nreds red) 1))
- (if (and (= (red-nreds red) 1) (vector-ref consistent i))
- (add-action i 'default (- (car (red-rules red))))
- (let ((k (vector-ref lookaheads (+ i 1))))
- (let loop ((j (vector-ref lookaheads i)))
- (if (< j k)
- (let ((rule (- (vector-ref LAruleno j)))
- (lav (vector-ref LA j)))
- (let loop2 ((token 0) (x (vector-ref lav 0)) (y 1) (z 0))
- (if (< token nterms)
- (begin
- (let ((in-la-set? (modulo x 2)))
- (if (= in-la-set? 1)
- (add-action i token rule)))
- (if (= y (BITS-PER-WORD))
- (loop2 (+ token 1)
- (vector-ref lav (+ z 1))
- 1
- (+ z 1))
- (loop2 (+ token 1) (quotient x 2) (+ y 1) z)))))
- (loop (+ j 1)))))))))
-
- (let ((shiftp (vector-ref shift-table i)))
- (if shiftp
- (let loop ((k (shift-shifts shiftp)))
- (if (pair? k)
- (let* ((state (car k))
- (symbol (vector-ref acces-symbol state)))
- (if (>= symbol nvars)
- (add-action i (- symbol nvars) state))
- (loop (cdr k))))))))
-
- (add-action final-state 0 'accept))
-
-(define (compact-action-table)
- (define (most-common-action acts)
- (let ((accums '()))
- (let loop ((l acts))
- (if (pair? l)
- (let* ((x (cdar l))
- (y (assv x accums)))
- (if (and (number? x) (< x 0))
- (if y
- (set-cdr! y (+ 1 (cdr y)))
- (set! accums (cons `(,x . 1) accums))))
- (loop (cdr l)))))
-
- (let loop ((l accums) (max 0) (sym #f))
- (if (null? l)
- sym
- (let ((x (car l)))
- (if (> (cdr x) max)
- (loop (cdr l) (cdr x) (car x))
- (loop (cdr l) max sym)))))))
-
- (do ((i 0 (+ i 1)))
- ((= i nstates))
- (let ((acts (vector-ref action-table i)))
- (if (vector? (vector-ref reduction-table i))
- (let ((act (most-common-action acts)))
- (vector-set! action-table i
- (cons `(default . ,(if act act 'error))
- (filter (lambda (x)
- (not (eq? (cdr x) act)))
- acts))))
- (vector-set! action-table i
- (cons `(default . *error*) acts))))))
-
-
-(define (output-action-table prefix)
- (display "(defconst ") (display prefix) (display "action-table") (newline)
- (display " [") (newline)
- (do ((i 0 (+ i 1)))
- ((= i nstates))
- (display " ")
- (write (vector-ref action-table i))
- (newline))
- (display " ])") (newline)
- (newline))
-
-(define (output-goto-table prefix)
- (display "(defconst ") (display prefix) (display "goto-table") (newline)
- (display " [") (newline)
- (do ((i 0 (+ i 1)))
- ((= i nstates))
- (display " ")
- (let ((shifts (vector-ref shift-table i)))
- (if shifts
- (begin
- (display "(")
- (let loop ((l (shift-shifts shifts)))
- (if (null? l)
- (display ")")
- (let* ((state (car l))
- (symbol (vector-ref acces-symbol state)))
- (if (< symbol nvars)
- (display `(,symbol . ,state)))
- (loop (cdr l))))))
- (display '())))
- (newline))
- (display " ])") (newline)
- (newline))
-
-(define (output-reduction-table gram/actions prefix)
- (display "(defconst ") (display prefix) (display "reduction-table") (newline)
- (display " (vector") (newline)
- (display " '()") (newline)
- (for-each
- (lambda (p)
- (let ((act (cdr p)))
- (display " (lambda (stack sp goto-table $look)") (newline)
- (let* ((nt (caar p)) (rhs (cdar p)) (n (length rhs)))
- (display " (let* (")
- (if act
- (let loop ((i 1) (l rhs))
- (if (not (null? l))
- (let ((rest (cdr l)))
- (if (> i 1) (begin (newline) (display " ")))
- (display "($") (display (+ (- n i) 1)) (display " ")
- (display "(aref stack (- sp ")
- (display (- (* i 2) 1))
- (display ")))")
- (loop (+ i 1) rest)))))
- (display ")")
- (newline)
- (display " ")
- (if (= nt 0)
- (display "(accept $1)")
- (begin
- (display "(lr-push stack (- sp ")
- (display (* 2 n))
- (display ") ")
- (display nt)
- (display " goto-table ")
- (write (cdr p))
- (display ")")))
- (display "))") (newline))))
- gram/Actions)
- (display " ))") (newline)
- (newline))
-
-(define (output-header header parser-prefix)
- (display header)
- (display "(require 'lr-driver)") (newline)
- (newline))
-
-(define (output-footer footer)
- (display footer) (newline)
- (newline))
-
-(define (output-parser-def parser-prefix prefix)
- (display "(defun ") (display parser-prefix) (display "parse") (display "(scanner errorhandler)") (newline)
- (display " (lr-parse scanner errorhandler ") (newline)
- (display " ") (display prefix) (display "action-table") (newline)
- (display " ") (display prefix) (display "goto-table") (newline)
- (display " ") (display prefix) (display "reduction-table") (newline)
- (display " ") (display prefix) (display "token-defs))") (newline)
- (newline))
-
-(define (output-token-defs terms prefix)
- (let loop ((i 0) (l terms))
- (if (pair? l)
- (let ((x (car l)))
- (display "(defconst ") (display prefix)
- (write x)
- (display #\tab)
- (display i)
- (display ")")
- (newline)
- (loop (+ i 1) (cdr l)))))
- (newline)
- (display "(defconst ") (display prefix) (display "token-defs") (newline)
- (display " (list ") (newline)
- (let loop ((i 0) (l terms))
- (if (pair? l)
- (begin
- (display " (cons ")
- (display i)
- (display " \"") (display (car l)) (display "\")")
- (newline)
- (loop (+ i 1) (cdr l)))))
- (display " ))") (newline)
- (newline))
-
-;; --
-
-(define (rewrite-grammar grammar proc)
-
- (define eoi '*EOI*)
-
- (if (not (pair? grammar))
- (error "Grammar definition must be a non-empty list")
- (let loop1 ((lst grammar) (rev-terms '()))
- (if (and (pair? lst) (not (pair? (car lst)))) ; definition d'un terminal?
- (let ((term (car lst)))
- (cond ((not (valid-terminal? term))
- (error "Invalid terminal:" term))
- ((member term rev-terms)
- (error "Terminal previously defined:" term))
- (else
- (loop1 (cdr lst) (cons term rev-terms)))))
- (let loop2 ((lst lst) (rev-nonterm-defs '()))
- (if (pair? lst)
- (let ((def (car lst)))
- (if (not (pair? def))
- (error "Nonterminal definition must be a non-empty list")
- (let ((nonterm (car def)))
- (cond ((not (valid-nonterminal? nonterm))
- (error "Invalid nonterminal:" nonterm))
- ((or (member nonterm rev-terms)
- (assoc nonterm rev-nonterm-defs))
- (error "Nonterminal previously defined:" nonterm))
- (else
- (loop2 (cdr lst)
- (cons def rev-nonterm-defs)))))))
- (let* ((terms (cons eoi (reverse rev-terms)))
- (nonterm-defs (reverse rev-nonterm-defs))
- (nonterms (cons '*start* (map car nonterm-defs))))
- (if (= (length nonterms) 1)
- (error "Grammar must contain at least one nonterminal")
- (let ((compiled-nonterminals
- (map (lambda (nonterm-def)
- (rewrite-nonterm-def nonterm-def
- terms
- nonterms))
- (cons `(*start* (,(cadr nonterms) ,eoi) : $1)
- nonterm-defs))))
- (proc terms
- nonterms
- (map (lambda (x) (cons (caaar x) (map cdar x)))
- compiled-nonterminals)
- (apply append compiled-nonterminals)))))))))))
-
-
-(define (rewrite-nonterm-def nonterm-def terms nonterms)
-
- (define No-NT (length nonterms))
-
- (define (encode x)
- (let ((PosInNT (pos-in-list x nonterms)))
- (if PosInNT
- PosInNT
- (let ((PosInT (pos-in-list x terms)))
- (if PosInT
- (+ No-NT PosInT)
- (error "undefined symbol : " x))))))
-
- (if (not (pair? (cdr nonterm-def)))
- (error "At least one production needed for nonterminal" (car nonterm-def))
- (let ((name (symbol->string (car nonterm-def))))
- (let loop1 ((lst (cdr nonterm-def))
- (i 1)
- (rev-productions-and-actions '()))
- (if (not (pair? lst))
- (reverse rev-productions-and-actions)
- (let* ((rhs (car lst))
- (rest (cdr lst))
- (prod (map encode (cons (car nonterm-def) rhs))))
- (for-each (lambda (x)
- (if (not (or (member x terms) (member x nonterms)))
- (error "Invalid terminal or nonterminal" x)))
- rhs)
- (if (and (pair? rest)
- (eq? (car rest) ':)
- (pair? (cdr rest)))
- (loop1 (cddr rest)
- (+ i 1)
- (cons (cons prod (cadr rest))
- rev-productions-and-actions))
- (let* ((rhs-length (length rhs))
- (action
- (cons 'VECTOR
- (cons (list 'QUOTE (string->symbol
- (string-append
- name
- "-"
- (number->string i))))
- (let loop-j ((j 1))
- (if (> j rhs-length)
- '()
- (cons (string->symbol
- (string-append
- "$"
- (number->string j)))
- (loop-j (+ j 1)))))))))
- (loop1 rest
- (+ i 1)
- (cons (cons prod action)
- rev-productions-and-actions))))))))))
-
-(define (valid-nonterminal? x)
- (symbol? x))
-
-(define (valid-terminal? x)
- (symbol? x)) ; DB
-
-;; ---------------------------------------------------------------------- ;;
-;; Miscellaneous ;;
-;; ---------------------------------------------------------------------- ;;
-(define (pos-in-list x lst)
- (let loop ((lst lst) (i 0))
- (cond ((not (pair? lst)) #f)
- ((equal? (car lst) x) i)
- (else (loop (cdr lst) (+ i 1))))))
-
-(define (sunion lst1 lst2) ; union of sorted lists
- (let loop ((L1 lst1)
- (L2 lst2))
- (cond ((null? L1) L2)
- ((null? L2) L1)
- (else
- (let ((x (car L1)) (y (car L2)))
- (cond
- ((> x y)
- (cons y (loop L1 (cdr L2))))
- ((< x y)
- (cons x (loop (cdr L1) L2)))
- (else
- (loop (cdr L1) L2))
- ))))))
-
-(define (sinsert elem lst)
- (let loop ((l1 lst))
- (if (null? l1)
- (cons elem l1)
- (let ((x (car l1)))
- (cond ((< elem x)
- (cons elem l1))
- ((> elem x)
- (cons x (loop (cdr l1))))
- (else
- l1))))))
-
-(define (filter p lst)
- (let loop ((l lst))
- (if (null? l)
- '()
- (let ((x (car l)) (y (cdr l)))
- (if (p x)
- (cons x (loop y))
- (loop y))))))
-
-;; ---------------------------------------------------------------------- ;;
-;; Debugging tools ... ;;
-;; ---------------------------------------------------------------------- ;;
-(define the-terminals #f)
-(define the-nonterminals #f)
-
-(define (print-item item-no)
- (let loop ((i item-no))
- (let ((v (vector-ref ritem i)))
- (if (>= v 0)
- (loop (+ i 1))
- (let* ((rlno (- v))
- (nt (vector-ref rlhs rlno)))
- (display (vector-ref the-nonterminals nt)) (display " --> ")
- (let loop ((i (vector-ref rrhs rlno)))
- (let ((v (vector-ref ritem i)))
- (if (= i item-no)
- (display ". "))
- (if (>= v 0)
- (begin
- (print-symbol v)
- (display " ")
- (loop (+ i 1)))
- (begin
- (display " (rule ")
- (display (- v))
- (display ")")
- (newline))))))))))
-
-(define (print-symbol n)
- (display (if (>= n nvars)
- (vector-ref the-terminals (- n nvars))
- (vector-ref the-nonterminals n))))
-
-(define (print-states)
- (define (print-action act)
- (cond
- ((eq? act '*error*)
- (display " : Error"))
- ((eq? act 'accept)
- (display " : Accept input"))
- ((< act 0)
- (display " : reduce using rule ")
- (display (- act)))
- (else
- (display " : shift and goto state ")
- (display act)))
- (newline)
- #t)
-
- (define (print-actions acts)
- (let loop ((l acts))
- (if (null? l)
- #t
- (let ((sym (caar l))
- (act (cdar l)))
- (display " ")
- (cond
- ((eq? sym 'default)
- (display "default action"))
- (else
- (print-symbol (+ sym nvars))))
- (print-action act)
- (loop (cdr l))))))
-
- (if (not action-table)
- (begin
- (display "No generated parser available!")
- (newline)
- #f)
- (begin
- (display "State table") (newline)
- (display "-----------") (newline) (newline)
-
- (let loop ((l first-state))
- (if (null? l)
- #t
- (let* ((core (car l))
- (i (core-number core))
- (items (core-items core))
- (actions (vector-ref action-table i)))
- (display "state ") (display i) (newline)
- (newline)
- (for-each (lambda (x) (display " ") (print-item x))
- items)
- (newline)
- (print-actions actions)
- (newline)
- (loop (cdr l))))))))
-
-
-
projects / elisp / flim.git / blobdiff