--- /dev/null
+;;;
+;;;; An Efficient and Portable LALR(1) Parser Generator for Scheme
+;;;
+;; Copyright 1993, 2010 Dominique Boucher
+;;
+;; This program is free software: you can redistribute it and/or
+;; modify it under the terms of the GNU Lesser General Public License
+;; as published by the Free Software Foundation, either version 3 of
+;; the License, or (at your option) any later version.
+;;
+;; This program 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 Lesser General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+(define *lalr-scm-version* "2.4.1")
+
+
+(cond-expand
+
+ ;; -- Gambit-C
+ (gambit
+
+ (define-macro (def-macro form . body)
+ `(define-macro ,form (let () ,@body)))
+
+ (def-macro (BITS-PER-WORD) 28)
+ (def-macro (logical-or x . y) `(bitwise-ior ,x ,@y))
+ (def-macro (lalr-error msg obj) `(error ,msg ,obj))
+
+ (define pprint pretty-print)
+ (define lalr-keyword? keyword?))
+
+ ;; --
+ (bigloo
+ (define-macro (def-macro form . body)
+ `(define-macro ,form (let () ,@body)))
+
+ (define pprint (lambda (obj) (write obj) (newline)))
+ (define lalr-keyword? keyword?)
+ (def-macro (BITS-PER-WORD) 29)
+ (def-macro (logical-or x . y) `(bit-or ,x ,@y))
+ (def-macro (lalr-error msg obj) `(error "lalr-parser" ,msg ,obj)))
+
+ ;; -- Chicken
+ (chicken
+
+ (define-macro (def-macro form . body)
+ `(define-macro ,form (let () ,@body)))
+
+ (define pprint pretty-print)
+ (define lalr-keyword? symbol?)
+ (def-macro (BITS-PER-WORD) 30)
+ (def-macro (logical-or x . y) `(bitwise-ior ,x ,@y))
+ (def-macro (lalr-error msg obj) `(error ,msg ,obj)))
+
+ ;; -- STKlos
+ (stklos
+ (require "pp")
+
+ (define (pprint form) (pp form :port (current-output-port)))
+
+ (define lalr-keyword? keyword?)
+ (define-macro (BITS-PER-WORD) 30)
+ (define-macro (logical-or x . y) `(bit-or ,x ,@y))
+ (define-macro (lalr-error msg obj) `(error 'lalr-parser ,msg ,obj)))
+
+ ;; -- Guile
+ (guile
+ (use-modules (ice-9 pretty-print))
+ (use-modules (srfi srfi-9))
+
+ (define pprint pretty-print)
+ (define lalr-keyword? symbol?)
+ (define-macro (BITS-PER-WORD) 30)
+ (define-macro (logical-or x . y) `(logior ,x ,@y))
+ (define-macro (lalr-error msg obj) `(error ,msg ,obj)))
+
+ ;; -- Kawa
+ (kawa
+ (require 'pretty-print)
+ (define (BITS-PER-WORD) 30)
+ (define logical-or logior)
+ (define (lalr-keyword? obj) (keyword? obj))
+ (define (pprint obj) (pretty-print obj))
+ (define (lalr-error msg obj) (error msg obj)))
+
+ ;; -- SISC
+ (sisc
+ (import logicops)
+ (import record)
+
+ (define pprint pretty-print)
+ (define lalr-keyword? symbol?)
+ (define-macro BITS-PER-WORD (lambda () 32))
+ (define-macro logical-or (lambda (x . y) `(logor ,x ,@y)))
+ (define-macro (lalr-error msg obj) `(error "~a ~S:" ,msg ,obj)))
+
+
+ (else
+ (error "Unsupported Scheme system")))
+
+
+(define-record-type lexical-token
+ (make-lexical-token category source value)
+ lexical-token?
+ (category lexical-token-category)
+ (source lexical-token-source)
+ (value lexical-token-value))
+
+
+(define-record-type source-location
+ (make-source-location input line column offset length)
+ source-location?
+ (input source-location-input)
+ (line source-location-line)
+ (column source-location-column)
+ (offset source-location-offset)
+ (length source-location-length))
+
+
+
+ ;; - Macros pour la gestion des vecteurs de bits
+
+(define-macro (lalr-parser . arguments)
+ (define (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))))
+
+ (define (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
+
+ (define (new-core) (make-vector 4 0))
+ (define (set-core-number! c n) (vector-set! c 0 n))
+ (define (set-core-acc-sym! c s) (vector-set! c 1 s))
+ (define (set-core-nitems! c n) (vector-set! c 2 n))
+ (define (set-core-items! c i) (vector-set! c 3 i))
+ (define (core-number c) (vector-ref c 0))
+ (define (core-acc-sym c) (vector-ref c 1))
+ (define (core-nitems c) (vector-ref c 2))
+ (define (core-items c) (vector-ref c 3))
+
+ (define (new-shift) (make-vector 3 0))
+ (define (set-shift-number! c x) (vector-set! c 0 x))
+ (define (set-shift-nshifts! c x) (vector-set! c 1 x))
+ (define (set-shift-shifts! c x) (vector-set! c 2 x))
+ (define (shift-number s) (vector-ref s 0))
+ (define (shift-nshifts s) (vector-ref s 1))
+ (define (shift-shifts s) (vector-ref s 2))
+
+ (define (new-red) (make-vector 3 0))
+ (define (set-red-number! c x) (vector-set! c 0 x))
+ (define (set-red-nreds! c x) (vector-set! c 1 x))
+ (define (set-red-rules! c x) (vector-set! c 2 x))
+ (define (red-number c) (vector-ref c 0))
+ (define (red-nreds c) (vector-ref c 1))
+ (define (red-rules c) (vector-ref c 2))
+
+
+ (define (new-set nelem)
+ (make-vector nelem 0))
+
+
+ (define (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 driver-name 'lr-driver)
+
+ (define (gen-tables! tokens gram )
+ (initialize-all)
+ (rewrite-grammar
+ tokens
+ gram
+ (lambda (terms terms/prec vars gram gram/actions)
+ (set! the-terminals/prec (list->vector terms/prec))
+ (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 terms)
+ gram/actions))))
+
+
+ (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)
+ (set! rule-precedences '()))
+
+
+ (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))))))))))))
+
+
+ (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)))))))))
+
+
+
+ (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))))))
+
+
+
+
+ (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))))))
+
+
+ (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))))))
+
+
+ (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))))))
+
+
+ ;; ----------------------------------------------------------------------
+ ;; operator precedence management
+ ;; ----------------------------------------------------------------------
+
+ ;; a vector of precedence descriptors where each element
+ ;; is of the form (terminal type precedence)
+ (define the-terminals/prec #f) ; terminal symbols with precedence
+ ; the precedence is an integer >= 0
+ (define (get-symbol-precedence sym)
+ (caddr (vector-ref the-terminals/prec sym)))
+ ; the operator type is either 'none, 'left, 'right, or 'nonassoc
+ (define (get-symbol-assoc sym)
+ (cadr (vector-ref the-terminals/prec sym)))
+
+ (define rule-precedences '())
+ (define (add-rule-precedence! rule sym)
+ (set! rule-precedences
+ (cons (cons rule sym) rule-precedences)))
+
+ (define (get-rule-precedence ruleno)
+ (cond
+ ((assq ruleno rule-precedences)
+ => (lambda (p)
+ (get-symbol-precedence (cdr p))))
+ (else
+ ;; process the rule symbols from left to right
+ (let loop ((i (vector-ref rrhs ruleno))
+ (prec 0))
+ (let ((item (vector-ref ritem i)))
+ ;; end of rule
+ (if (< item 0)
+ prec
+ (let ((i1 (+ i 1)))
+ (if (>= item nvars)
+ ;; it's a terminal symbol
+ (loop i1 (get-symbol-precedence (- item nvars)))
+ (loop i1 prec)))))))))
+
+ ;; ----------------------------------------------------------------------
+ ;; Build the various tables
+ ;; ----------------------------------------------------------------------
+
+ (define expected-conflicts 0)
+
+ (define (build-tables)
+
+ (define (resolve-conflict sym rule)
+ (let ((sym-prec (get-symbol-precedence sym))
+ (sym-assoc (get-symbol-assoc sym))
+ (rule-prec (get-rule-precedence rule)))
+ (cond
+ ((> sym-prec rule-prec) 'shift)
+ ((< sym-prec rule-prec) 'reduce)
+ ((eq? sym-assoc 'left) 'reduce)
+ ((eq? sym-assoc 'right) 'shift)
+ (else 'none))))
+
+ (define conflict-messages '())
+
+ (define (add-conflict-message . l)
+ (set! conflict-messages (cons l conflict-messages)))
+
+ (define (log-conflicts)
+ (if (> (length conflict-messages) expected-conflicts)
+ (for-each
+ (lambda (message)
+ (for-each display message)
+ (newline))
+ conflict-messages)))
+
+ ;; --- Add an action to the action table
+ (define (add-action state symbol new-action)
+ (let* ((state-actions (vector-ref action-table state))
+ (actions (assv symbol state-actions)))
+ (if (pair? actions)
+ (let ((current-action (cadr actions)))
+ (if (not (= new-action current-action))
+ ;; -- there is a conflict
+ (begin
+ (if (and (<= current-action 0) (<= new-action 0))
+ ;; --- reduce/reduce conflict
+ (begin
+ (add-conflict-message
+ "%% Reduce/Reduce conflict (reduce " (- new-action) ", reduce " (- current-action)
+ ") on '" (get-symbol (+ symbol nvars)) "' in state " state)
+ (if (eq? driver-name 'glr-driver)
+ (set-cdr! (cdr actions) (cons new-action (cddr actions)))
+ (set-car! (cdr actions) (max current-action new-action))))
+ ;; --- shift/reduce conflict
+ ;; can we resolve the conflict using precedences?
+ (case (resolve-conflict symbol (- current-action))
+ ;; -- shift
+ ((shift) (if (eq? driver-name 'glr-driver)
+ (set-cdr! (cdr actions) (cons new-action (cddr actions)))
+ (set-car! (cdr actions) new-action)))
+ ;; -- reduce
+ ((reduce) #f) ; well, nothing to do...
+ ;; -- signal a conflict!
+ (else (add-conflict-message
+ "%% Shift/Reduce conflict (shift " new-action ", reduce " (- current-action)
+ ") on '" (get-symbol (+ symbol nvars)) "' in state " state)
+ (if (eq? driver-name 'glr-driver)
+ (set-cdr! (cdr actions) (cons new-action (cddr actions)))
+ (set-car! (cdr actions) new-action))))))))
+
+ (vector-set! action-table state (cons (list symbol new-action) state-actions)))))
+
+ (define (add-action-for-all-terminals state action)
+ (do ((i 1 (+ i 1)))
+ ((= i nterms))
+ (add-action state i action)))
+
+ (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-for-all-terminals i (- (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)
+ (log-conflicts))
+
+ (define (compact-action-table terms)
+ (define (most-common-action acts)
+ (let ((accums '()))
+ (let loop ((l acts))
+ (if (pair? l)
+ (let* ((x (cadar 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)))))))
+
+ (define (translate-terms acts)
+ (map (lambda (act)
+ (cons (list-ref terms (car act))
+ (cdr act)))
+ acts))
+
+ (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*))
+ (translate-terms
+ (lalr-filter (lambda (x)
+ (not (and (= (length x) 2)
+ (eq? (cadr x) act))))
+ acts)))))
+ (vector-set! action-table i
+ (cons `(*default* *error*)
+ (translate-terms acts)))))))
+
+
+
+ ;; --
+
+ (define (rewrite-grammar tokens grammar k)
+
+ (define eoi '*eoi*)
+
+ (define (check-terminal term terms)
+ (cond
+ ((not (valid-terminal? term))
+ (lalr-error "invalid terminal: " term))
+ ((member term terms)
+ (lalr-error "duplicate definition of terminal: " term))))
+
+ (define (prec->type prec)
+ (cdr (assq prec '((left: . left)
+ (right: . right)
+ (nonassoc: . nonassoc)))))
+
+ (cond
+ ;; --- a few error conditions
+ ((not (list? tokens))
+ (lalr-error "Invalid token list: " tokens))
+ ((not (pair? grammar))
+ (lalr-error "Grammar definition must have a non-empty list of productions" '()))
+
+ (else
+ ;; --- check the terminals
+ (let loop1 ((lst tokens)
+ (rev-terms '())
+ (rev-terms/prec '())
+ (prec-level 0))
+ (if (pair? lst)
+ (let ((term (car lst)))
+ (cond
+ ((pair? term)
+ (if (and (memq (car term) '(left: right: nonassoc:))
+ (not (null? (cdr term))))
+ (let ((prec (+ prec-level 1))
+ (optype (prec->type (car term))))
+ (let loop-toks ((l (cdr term))
+ (rev-terms rev-terms)
+ (rev-terms/prec rev-terms/prec))
+ (if (null? l)
+ (loop1 (cdr lst) rev-terms rev-terms/prec prec)
+ (let ((term (car l)))
+ (check-terminal term rev-terms)
+ (loop-toks
+ (cdr l)
+ (cons term rev-terms)
+ (cons (list term optype prec) rev-terms/prec))))))
+
+ (lalr-error "invalid operator precedence specification: " term)))
+
+ (else
+ (check-terminal term rev-terms)
+ (loop1 (cdr lst)
+ (cons term rev-terms)
+ (cons (list term 'none 0) rev-terms/prec)
+ prec-level))))
+
+ ;; --- check the grammar rules
+ (let loop2 ((lst grammar) (rev-nonterm-defs '()))
+ (if (pair? lst)
+ (let ((def (car lst)))
+ (if (not (pair? def))
+ (lalr-error "Nonterminal definition must be a non-empty list" '())
+ (let ((nonterm (car def)))
+ (cond ((not (valid-nonterminal? nonterm))
+ (lalr-error "Invalid nonterminal:" nonterm))
+ ((or (member nonterm rev-terms)
+ (assoc nonterm rev-nonterm-defs))
+ (lalr-error "Nonterminal previously defined:" nonterm))
+ (else
+ (loop2 (cdr lst)
+ (cons def rev-nonterm-defs)))))))
+ (let* ((terms (cons eoi (cons 'error (reverse rev-terms))))
+ (terms/prec (cons '(eoi none 0) (cons '(error none 0) (reverse rev-terms/prec))))
+ (nonterm-defs (reverse rev-nonterm-defs))
+ (nonterms (cons '*start* (map car nonterm-defs))))
+ (if (= (length nonterms) 1)
+ (lalr-error "Grammar must contain at least one nonterminal" '())
+ (let loop-defs ((defs (cons `(*start* (,(cadr nonterms) ,eoi) : $1)
+ nonterm-defs))
+ (ruleno 0)
+ (comp-defs '()))
+ (if (pair? defs)
+ (let* ((nonterm-def (car defs))
+ (compiled-def (rewrite-nonterm-def
+ nonterm-def
+ ruleno
+ terms nonterms)))
+ (loop-defs (cdr defs)
+ (+ ruleno (length compiled-def))
+ (cons compiled-def comp-defs)))
+
+ (let ((compiled-nonterm-defs (reverse comp-defs)))
+ (k terms
+ terms/prec
+ nonterms
+ (map (lambda (x) (cons (caaar x) (map cdar x)))
+ compiled-nonterm-defs)
+ (apply append compiled-nonterm-defs))))))))))))))
+
+
+ (define (rewrite-nonterm-def nonterm-def ruleno 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)
+ (lalr-error "undefined symbol : " x))))))
+
+ (define (process-prec-directive rhs ruleno)
+ (let loop ((l rhs))
+ (if (null? l)
+ '()
+ (let ((first (car l))
+ (rest (cdr l)))
+ (cond
+ ((or (member first terms) (member first nonterms))
+ (cons first (loop rest)))
+ ((and (pair? first)
+ (eq? (car first) 'prec:))
+ (if (and (pair? (cdr first))
+ (null? (cddr first))
+ (member (cadr first) terms))
+ (if (null? rest)
+ (begin
+ (add-rule-precedence! ruleno (pos-in-list (cadr first) terms))
+ (loop rest))
+ (lalr-error "prec: directive should be at end of rule: " rhs))
+ (lalr-error "Invalid prec: directive: " first)))
+ (else
+ (lalr-error "Invalid terminal or nonterminal: " first)))))))
+
+ (define (check-error-production rhs)
+ (let loop ((rhs rhs))
+ (if (pair? rhs)
+ (begin
+ (if (and (eq? (car rhs) 'error)
+ (or (null? (cdr rhs))
+ (not (member (cadr rhs) terms))
+ (not (null? (cddr rhs)))))
+ (lalr-error "Invalid 'error' production. A single terminal symbol must follow the 'error' token.:" rhs))
+ (loop (cdr rhs))))))
+
+
+ (if (not (pair? (cdr nonterm-def)))
+ (lalr-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 (process-prec-directive (car lst) (+ ruleno i -1)))
+ (rest (cdr lst))
+ (prod (map encode (cons (car nonterm-def) rhs))))
+ ;; -- check for undefined tokens
+ (for-each (lambda (x)
+ (if (not (or (member x terms) (member x nonterms)))
+ (lalr-error "Invalid terminal or nonterminal:" x)))
+ rhs)
+ ;; -- check 'error' productions
+ (check-error-production 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 (lalr-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) ; names of terminal symbols
+ (define the-nonterminals #f) ; non-terminals
+
+ (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
+ (display (get-symbol v))
+ (display " ")
+ (loop (+ i 1)))
+ (begin
+ (display " (rule ")
+ (display (- v))
+ (display ")")
+ (newline))))))))))
+
+ (define (get-symbol n)
+ (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 (cadar l)))
+ (display " ")
+ (cond
+ ((eq? sym 'default)
+ (display "default action"))
+ (else
+ (if (number? sym)
+ (display (get-symbol (+ sym nvars)))
+ (display sym))))
+ (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))))))))
+
+
+
+ ;; ----------------------------------------------------------------------
+
+ (define build-goto-table
+ (lambda ()
+ `(vector
+ ,@(map
+ (lambda (shifts)
+ (list 'quote
+ (if shifts
+ (let loop ((l (shift-shifts shifts)))
+ (if (null? l)
+ '()
+ (let* ((state (car l))
+ (symbol (vector-ref acces-symbol state)))
+ (if (< symbol nvars)
+ (cons `(,symbol . ,state)
+ (loop (cdr l)))
+ (loop (cdr l))))))
+ '())))
+ (vector->list shift-table)))))
+
+
+ (define build-reduction-table
+ (lambda (gram/actions)
+ `(vector
+ '()
+ ,@(map
+ (lambda (p)
+ (let ((act (cdr p)))
+ `(lambda ,(if (eq? driver-name 'lr-driver)
+ '(___stack ___sp ___goto-table ___push yypushback)
+ '(___sp ___goto-table ___push))
+ ,(let* ((nt (caar p)) (rhs (cdar p)) (n (length rhs)))
+ `(let* (,@(if act
+ (let loop ((i 1) (l rhs))
+ (if (pair? l)
+ (let ((rest (cdr l)))
+ (cons
+ `(,(string->symbol
+ (string-append
+ "$"
+ (number->string
+ (+ (- n i) 1))))
+ ,(if (eq? driver-name 'lr-driver)
+ `(vector-ref ___stack (- ___sp ,(- (* i 2) 1)))
+ `(list-ref ___sp ,(+ (* (- i 1) 2) 1))))
+ (loop (+ i 1) rest)))
+ '()))
+ '()))
+ ,(if (= nt 0)
+ '$1
+ `(___push ,n ,nt ,(cdr p) ,@(if (eq? driver-name 'lr-driver) '() '(___sp)))))))))
+
+ gram/actions))))
+
+
+
+ ;; Options
+
+ (define *valid-options*
+ (list
+ (cons 'out-table:
+ (lambda (option)
+ (and (list? option)
+ (= (length option) 2)
+ (string? (cadr option)))))
+ (cons 'output:
+ (lambda (option)
+ (and (list? option)
+ (= (length option) 3)
+ (symbol? (cadr option))
+ (string? (caddr option)))))
+ (cons 'expect:
+ (lambda (option)
+ (and (list? option)
+ (= (length option) 2)
+ (integer? (cadr option))
+ (>= (cadr option) 0))))
+
+ (cons 'driver:
+ (lambda (option)
+ (and (list? option)
+ (= (length option) 2)
+ (symbol? (cadr option))
+ (memq (cadr option) '(lr glr)))))))
+
+
+ (define (validate-options options)
+ (for-each
+ (lambda (option)
+ (let ((p (assoc (car option) *valid-options*)))
+ (if (or (not p)
+ (not ((cdr p) option)))
+ (lalr-error "Invalid option:" option))))
+ options))
+
+
+ (define (output-parser! options code)
+ (let ((option (assq 'output: options)))
+ (if option
+ (let ((parser-name (cadr option))
+ (file-name (caddr option)))
+ (with-output-to-file file-name
+ (lambda ()
+ (pprint `(define ,parser-name ,code))
+ (newline)))))))
+
+
+ (define (output-table! options)
+ (let ((option (assq 'out-table: options)))
+ (if option
+ (let ((file-name (cadr option)))
+ (with-output-to-file file-name print-states)))))
+
+
+ (define (set-expected-conflicts! options)
+ (let ((option (assq 'expect: options)))
+ (set! expected-conflicts (if option (cadr option) 0))))
+
+ (define (set-driver-name! options)
+ (let ((option (assq 'driver: options)))
+ (if option
+ (let ((driver-type (cadr option)))
+ (set! driver-name (if (eq? driver-type 'glr) 'glr-driver 'lr-driver))))))
+
+
+ ;; -- arguments
+
+ (define (extract-arguments lst proc)
+ (let loop ((options '())
+ (tokens '())
+ (rules '())
+ (lst lst))
+ (if (pair? lst)
+ (let ((p (car lst)))
+ (cond
+ ((and (pair? p)
+ (lalr-keyword? (car p))
+ (assq (car p) *valid-options*))
+ (loop (cons p options) tokens rules (cdr lst)))
+ (else
+ (proc options p (cdr lst)))))
+ (lalr-error "Malformed lalr-parser form" lst))))
+
+
+ (define (build-driver options tokens rules)
+ (validate-options options)
+ (set-expected-conflicts! options)
+ (set-driver-name! options)
+ (let* ((gram/actions (gen-tables! tokens rules))
+ (code `(,driver-name ',action-table ,(build-goto-table) ,(build-reduction-table gram/actions))))
+
+ (output-table! options)
+ (output-parser! options code)
+ code))
+
+ (extract-arguments arguments build-driver))
+
+
+
+;;;
+;;;; --
+;;;; Implementation of the lr-driver
+;;;
+
+
+(cond-expand
+ (gambit
+ (declare
+ (standard-bindings)
+ (fixnum)
+ (block)
+ (not safe)))
+ (chicken
+ (declare
+ (uses extras)
+ (usual-integrations)
+ (fixnum)
+ (not safe)))
+ (else))
+
+
+;;;
+;;;; Source location utilities
+;;;
+
+
+;; This function assumes that src-location-1 and src-location-2 are source-locations
+;; Returns #f if they are not locations for the same input
+(define (combine-locations src-location-1 src-location-2)
+ (let ((offset-1 (source-location-offset src-location-1))
+ (offset-2 (source-location-offset src-location-2))
+ (length-1 (source-location-length src-location-1))
+ (length-2 (source-location-length src-location-2)))
+
+ (cond ((not (equal? (source-location-input src-location-1)
+ (source-location-input src-location-2)))
+ #f)
+ ((or (not (number? offset-1)) (not (number? offset-2))
+ (not (number? length-1)) (not (number? length-2))
+ (< offset-1 0) (< offset-2 0)
+ (< length-1 0) (< length-2 0))
+ (make-source-location (source-location-input src-location-1)
+ (source-location-line src-location-1)
+ (source-location-column src-location-1)
+ -1 -1))
+ ((<= offset-1 offset-2)
+ (make-source-location (source-location-input src-location-1)
+ (source-location-line src-location-1)
+ (source-location-column src-location-1)
+ offset-1
+ (- (+ offset-2 length-2) offset-1)))
+ (else
+ (make-source-location (source-location-input src-location-1)
+ (source-location-line src-location-1)
+ (source-location-column src-location-1)
+ offset-2
+ (- (+ offset-1 length-1) offset-2))))))
+
+
+;;;
+;;;; LR-driver
+;;;
+
+
+(define *max-stack-size* 500)
+
+(define (lr-driver action-table goto-table reduction-table)
+ (define ___atable action-table)
+ (define ___gtable goto-table)
+ (define ___rtable reduction-table)
+
+ (define ___lexerp #f)
+ (define ___errorp #f)
+
+ (define ___stack #f)
+ (define ___sp 0)
+
+ (define ___curr-input #f)
+ (define ___reuse-input #f)
+
+ (define ___input #f)
+ (define (___consume)
+ (set! ___input (if ___reuse-input ___curr-input (___lexerp)))
+ (set! ___reuse-input #f)
+ (set! ___curr-input ___input))
+
+ (define (___pushback)
+ (set! ___reuse-input #t))
+
+ (define (___initstack)
+ (set! ___stack (make-vector *max-stack-size* 0))
+ (set! ___sp 0))
+
+ (define (___growstack)
+ (let ((new-stack (make-vector (* 2 (vector-length ___stack)) 0)))
+ (let loop ((i (- (vector-length ___stack) 1)))
+ (if (>= i 0)
+ (begin
+ (vector-set! new-stack i (vector-ref ___stack i))
+ (loop (- i 1)))))
+ (set! ___stack new-stack)))
+
+ (define (___checkstack)
+ (if (>= ___sp (vector-length ___stack))
+ (___growstack)))
+
+ (define (___push delta new-category lvalue)
+ (set! ___sp (- ___sp (* delta 2)))
+ (let* ((state (vector-ref ___stack ___sp))
+ (new-state (cdr (assoc new-category (vector-ref ___gtable state)))))
+ (set! ___sp (+ ___sp 2))
+ (___checkstack)
+ (vector-set! ___stack ___sp new-state)
+ (vector-set! ___stack (- ___sp 1) lvalue)))
+
+ (define (___reduce st)
+ ((vector-ref ___rtable st) ___stack ___sp ___gtable ___push ___pushback))
+
+ (define (___shift token attribute)
+ (set! ___sp (+ ___sp 2))
+ (___checkstack)
+ (vector-set! ___stack (- ___sp 1) attribute)
+ (vector-set! ___stack ___sp token))
+
+ (define (___action x l)
+ (let ((y (assoc x l)))
+ (if y (cadr y) (cadar l))))
+
+ (define (___recover tok)
+ (let find-state ((sp ___sp))
+ (if (< sp 0)
+ (set! ___sp sp)
+ (let* ((state (vector-ref ___stack sp))
+ (act (assoc 'error (vector-ref ___atable state))))
+ (if act
+ (begin
+ (set! ___sp sp)
+ (___sync (cadr act) tok))
+ (find-state (- sp 2)))))))
+
+ (define (___sync state tok)
+ (let ((sync-set (map car (cdr (vector-ref ___atable state)))))
+ (set! ___sp (+ ___sp 4))
+ (___checkstack)
+ (vector-set! ___stack (- ___sp 3) #f)
+ (vector-set! ___stack (- ___sp 2) state)
+ (let skip ()
+ (let ((i (___category ___input)))
+ (if (eq? i '*eoi*)
+ (set! ___sp -1)
+ (if (memq i sync-set)
+ (let ((act (assoc i (vector-ref ___atable state))))
+ (vector-set! ___stack (- ___sp 1) #f)
+ (vector-set! ___stack ___sp (cadr act)))
+ (begin
+ (___consume)
+ (skip))))))))
+
+ (define (___category tok)
+ (if (lexical-token? tok)
+ (lexical-token-category tok)
+ tok))
+
+ (define (___value tok)
+ (if (lexical-token? tok)
+ (lexical-token-value tok)
+ tok))
+
+ (define (___run)
+ (let loop ()
+ (if ___input
+ (let* ((state (vector-ref ___stack ___sp))
+ (i (___category ___input))
+ (attr (___value ___input))
+ (act (___action i (vector-ref ___atable state))))
+
+ (cond ((not (symbol? i))
+ (___errorp "Syntax error: invalid token: " ___input)
+ #f)
+
+ ;; Input succesfully parsed
+ ((eq? act 'accept)
+ (vector-ref ___stack 1))
+
+ ;; Syntax error in input
+ ((eq? act '*error*)
+ (if (eq? i '*eoi*)
+ (begin
+ (___errorp "Syntax error: unexpected end of input")
+ #f)
+ (begin
+ (___errorp "Syntax error: unexpected token : " ___input)
+ (___recover i)
+ (if (>= ___sp 0)
+ (set! ___input #f)
+ (begin
+ (set! ___sp 0)
+ (set! ___input '*eoi*)))
+ (loop))))
+
+ ;; Shift current token on top of the stack
+ ((>= act 0)
+ (___shift act attr)
+ (set! ___input (if (eq? i '*eoi*) '*eoi* #f))
+ (loop))
+
+ ;; Reduce by rule (- act)
+ (else
+ (___reduce (- act))
+ (loop))))
+
+ ;; no lookahead, so check if there is a default action
+ ;; that does not require the lookahead
+ (let* ((state (vector-ref ___stack ___sp))
+ (acts (vector-ref ___atable state))
+ (defact (if (pair? acts) (cadar acts) #f)))
+ (if (and (= 1 (length acts)) (< defact 0))
+ (___reduce (- defact))
+ (___consume))
+ (loop)))))
+
+
+ (lambda (lexerp errorp)
+ (set! ___errorp errorp)
+ (set! ___lexerp lexerp)
+ (___initstack)
+ (___run)))
+
+
+;;;
+;;;; Simple-minded GLR-driver
+;;;
+
+
+(define (glr-driver action-table goto-table reduction-table)
+ (define ___atable action-table)
+ (define ___gtable goto-table)
+ (define ___rtable reduction-table)
+
+ (define ___lexerp #f)
+ (define ___errorp #f)
+
+ ;; -- Input handling
+
+ (define *input* #f)
+ (define (initialize-lexer lexer)
+ (set! ___lexerp lexer)
+ (set! *input* #f))
+ (define (consume)
+ (set! *input* (___lexerp)))
+
+ (define (token-category tok)
+ (if (lexical-token? tok)
+ (lexical-token-category tok)
+ tok))
+
+ (define (token-attribute tok)
+ (if (lexical-token? tok)
+ (lexical-token-value tok)
+ tok))
+
+ ;; -- Processes (stacks) handling
+
+ (define *processes* '())
+
+ (define (initialize-processes)
+ (set! *processes* '()))
+ (define (add-process process)
+ (set! *processes* (cons process *processes*)))
+ (define (get-processes)
+ (reverse *processes*))
+
+ (define (for-all-processes proc)
+ (let ((processes (get-processes)))
+ (initialize-processes)
+ (for-each proc processes)))
+
+ ;; -- parses
+ (define *parses* '())
+ (define (get-parses)
+ *parses*)
+ (define (initialize-parses)
+ (set! *parses* '()))
+ (define (add-parse parse)
+ (set! *parses* (cons parse *parses*)))
+
+
+ (define (push delta new-category lvalue stack)
+ (let* ((stack (drop stack (* delta 2)))
+ (state (car stack))
+ (new-state (cdr (assv new-category (vector-ref ___gtable state)))))
+ (cons new-state (cons lvalue stack))))
+
+ (define (reduce state stack)
+ ((vector-ref ___rtable state) stack ___gtable push))
+
+ (define (shift state symbol stack)
+ (cons state (cons symbol stack)))
+
+ (define (get-actions token action-list)
+ (let ((pair (assoc token action-list)))
+ (if pair
+ (cdr pair)
+ (cdar action-list)))) ;; get the default action
+
+
+ (define (run)
+ (let loop-tokens ()
+ (consume)
+ (let ((symbol (token-category *input*))
+ (attr (token-attribute *input*)))
+ (for-all-processes
+ (lambda (process)
+ (let loop ((stacks (list process)) (active-stacks '()))
+ (cond ((pair? stacks)
+ (let* ((stack (car stacks))
+ (state (car stack)))
+ (let actions-loop ((actions (get-actions symbol (vector-ref ___atable state)))
+ (active-stacks active-stacks))
+ (if (pair? actions)
+ (let ((action (car actions))
+ (other-actions (cdr actions)))
+ (cond ((eq? action '*error*)
+ (actions-loop other-actions active-stacks))
+ ((eq? action 'accept)
+ (add-parse (car (take-right stack 2)))
+ (actions-loop other-actions active-stacks))
+ ((>= action 0)
+ (let ((new-stack (shift action attr stack)))
+ (add-process new-stack))
+ (actions-loop other-actions active-stacks))
+ (else
+ (let ((new-stack (reduce (- action) stack)))
+ (actions-loop other-actions (cons new-stack active-stacks))))))
+ (loop (cdr stacks) active-stacks)))))
+ ((pair? active-stacks)
+ (loop (reverse active-stacks) '())))))))
+ (if (pair? (get-processes))
+ (loop-tokens))))
+
+
+ (lambda (lexerp errorp)
+ (set! ___errorp errorp)
+ (initialize-lexer lexerp)
+ (initialize-processes)
+ (initialize-parses)
+ (add-process '(0))
+ (run)
+ (get-parses)))
+
+
+(define (drop l n)
+ (cond ((and (> n 0) (pair? l))
+ (drop (cdr l) (- n 1)))
+ (else
+ l)))
+
+(define (take-right l n)
+ (drop l (- (length l) n)))
\ No newline at end of file
HCoop / bpt / guile.git / commitdiff