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chez-openbsd/examples/m4.ss
2022-07-29 15:12:07 +02:00

642 lines
23 KiB
Scheme

;;; m4.ss
;;; Copyright (C) 1988 R. Kent Dybvig
;;; Permission is hereby granted, free of charge, to any person obtaining a
;;; copy of this software and associated documentation files (the "Software"),
;;; to deal in the Software without restriction, including without limitation
;;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
;;; and/or sell copies of the Software, and to permit persons to whom the
;;; Software is furnished to do so, subject to the following conditions:
;;;
;;; The above copyright notice and this permission notice shall be included in
;;; all copies or substantial portions of the Software.
;;;
;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
;;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
;;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
;;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
;;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
;;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
;;; DEALINGS IN THE SOFTWARE.
;;; speed improvement ideas:
;;; use hash table rather than assoc for macro lookup
;;; use extensible string buffer in place of lists
;;; collect multiple characters when scanning text, arguments
;;; use fixnum arithmetic where appropriate
(eval-when (compile) (optimize-level 3))
(define lexeme-type car)
(define lexeme-value cdr)
(define-structure (ibuf ip) ([pb '()]))
(define oparen #\()
(define cparen #\))
(define m4-get-char
(lambda (ib)
(let ([pb (ibuf-pb ib)])
(if (null? pb)
(read-char (ibuf-ip ib))
(begin (set-ibuf-pb! ib (cdr pb))
(car pb))))))
(define m4-unget-char
(lambda (c ib)
(set-ibuf-pb! ib (cons c (ibuf-pb ib)))))
(define unget-string
(lambda (s ib)
(set-ibuf-pb! ib (append (string->list s) (ibuf-pb ib)))))
(define int->str
(lambda (num)
(format "~s" num)))
(define char->digit
(let ([zero (char->integer #\0)])
(lambda (c)
(- (char->integer c) zero))))
(define str->int
(let ([ustr->int
(lambda (s i n)
(let f ([a 0] [i i])
(if (= i n)
a
(f (+ (* a 10) (char->digit (string-ref s i)))
(+ i 1)))))])
(lambda (s)
(let ([n (string-length s)])
(if (= n 0)
0
(if (char=? (string-ref s 0) #\-)
(- (ustr->int s 1 n))
(ustr->int s 0 n)))))))
(define eval-string
(let ([str #f] [port #f] [token #f] [value #f])
(define eval-error
(lambda ()
(error 'm4 "invalid arithmetic expression ~s" str)))
(define next-token!
(lambda ()
(let ([c (read-char port)])
(cond
[(eof-object? c) (set! token 'eof)]
[(char-whitespace? c) (next-token!)]
[(char-numeric? c)
(let loop ([a (char->digit c)])
(let ([c (read-char port)])
(cond
[(eof-object? c)
(set! token 'integer)
(set! value a)]
[(char-numeric? c)
(loop (+ (* a 10) (char->digit c)))]
[else
(unread-char c port)
(set! token 'integer)
(set! value a)])))]
[(char=? c oparen) (set! token 'oparen)]
[(char=? c cparen) (set! token 'cparen)]
[(char=? c #\-) (set! token '-)]
[(char=? c #\*)
(let ([c (read-char port)])
(cond
[(eof-object? c) (set! token '*)]
[(char=? c #\*) (set! token '**)]
[else (unread-char c port) (set! token '*)]))]
[(char=? c #\+) (set! token '+)]
[(char=? c #\-) (set! token '+)]
[(char=? c #\/) (set! token '/)]
[(char=? c #\%) (set! token '%)]
[(char=? c #\!)
(let ([c (read-char port)])
(cond
[(eof-object? c) (set! token '!)]
[(char=? c #\=) (set! token '!=)]
[else (unread-char c port) (set! token '!)]))]
[(char=? c #\|)
(let ([c (read-char port)])
(cond
[(eof-object? c) (eval-error)]
[(char=? c #\|) (set! token 'or)]
[else (unread-char c port) (eval-error)]))]
[(char=? c #\&)
(let ([c (read-char port)])
(cond
[(eof-object? c) (eval-error)]
[(char=? c #\&) (set! token 'and)]
[else (unread-char c port) (eval-error)]))]
[(char=? c #\=)
(let ([c (read-char port)])
(cond
[(eof-object? c) (eval-error)]
[(char=? c #\=) (set! token '==)]
[else (unread-char c port) (eval-error)]))]
[(char=? c #\<)
(let ([c (read-char port)])
(cond
[(eof-object? c) (set! token '<)]
[(char=? c #\=) (set! token '<=)]
[else (unread-char c port) (set! token '<)]))]
[(char=? c #\>)
(let ([c (read-char port)])
(cond
[(eof-object? c) (set! token '>)]
[(char=? c #\=) (set! token '>=)]
[else (unread-char c port) (set! token '>)]))]))))
(define E0 ; or
(lambda ()
(E0* (E1))))
(define E0*
(lambda (v)
(case token
[or (next-token!) (E0* (if (= (+ v (E1)) 0) 0 1))]
[else v])))
(define E1 ; and
(lambda ()
(E1* (E2))))
(define E1*
(lambda (v)
(case token
[and (next-token!) (E1* (if (= (* v (E2)) 0) 0 1))]
[else v])))
(define E2 ; ==, !=
(lambda ()
(E2* (E3))))
(define E2*
(lambda (v)
(case token
[== (next-token!) (E2* (if (= v (E3)) 1 0))]
[!= (next-token!) (E2* (if (= v (E3)) 0 1))]
[else v])))
(define E3 ; <, <=, >, >=
(lambda ()
(E3* (E4))))
(define E3*
(lambda (v)
(case token
[< (next-token!) (E3* (if (< v (E4)) 1 0))]
[<= (next-token!) (E3* (if (<= v (E4)) 1 0))]
[> (next-token!) (E3* (if (> v (E4)) 1 0))]
[>= (next-token!) (E3* (if (>= v (E4)) 1 0))]
[else v])))
(define E4 ; +, -
(lambda ()
(E4* (E5))))
(define E4*
(lambda (v)
(case token
[+ (next-token!) (E4* (+ v (E5)))]
[- (next-token!) (E4* (- v (E5)))]
[else v])))
(define E5 ; *, /, %
(lambda ()
(E5* (E6))))
(define E5*
(lambda (v)
(case token
[* (next-token!) (E5* (* v (E6)))]
[/ (next-token!) (E5* (quotient v (E6)))]
[% (next-token!) (E5* (modulo v (E6)))]
[else v])))
(define E6 ; **
(lambda ()
(E6* (E7))))
(define E6*
(lambda (v)
(case token
[** (next-token!) (E6* (expt v (E7)))]
[else v])))
(define E7 ; -, integer, paren
(lambda ()
(case token
[- (next-token!) (- (E7))]
[! (next-token!) (if (= (E7) 0) 1 0)]
[oparen
(next-token!)
(let ([v (E0)])
(unless (eq? token 'cparen) (eval-error))
(next-token!)
v)]
[integer (next-token!) value]
[else (eval-error)])))
(lambda (s)
(fluid-let ([str s] [port (open-input-string s)] [token #f] [value #f])
(next-token!)
(let ([v (E0)])
(unless (eq? token 'eof) (eval-error))
v)))))
(define *divnum* #f)
(define *diversions* #f)
(define m4-put-string
(lambda (s)
(unless (= *divnum* -1)
(display s (vector-ref *diversions* *divnum*)))))
(define *open-quote* #f)
(define *close-quote* #f)
(define *macros* #f)
(define builtin-macros '())
(define *translit-table* #f)
(define define-builtin-macro
(lambda (name proc)
(set! builtin-macros (cons (cons name proc) builtin-macros))))
(define m4
(lambda (ofn ifn . rest)
(let ([op (open-output-file ofn 'replace)])
(fluid-let ([*macros* builtin-macros]
[*open-quote* #\`]
[*close-quote* #\']
[*translit-table* #f]
[*divnum* 0]
[*diversions* (vector op #f #f #f #f #f #f #f #f #f)])
(let loop ([ip (open-input-file ifn)] [rest rest])
(m4-process (make-ibuf ip) op)
(close-input-port ip)
(unless (null? rest)
(loop (open-input-file (car rest)) (cdr rest))))
(for-each undivert '(1 2 3 4 5 6 7 8 9)))
(close-output-port op))))
(define m4-process
(lambda (ib op)
(let ([lexeme (read-lexeme ib)])
(case (lexeme-type lexeme)
[(comment literal)
(m4-put-string (lexeme-value lexeme))
(m4-process ib op)]
[macro
((cdr (lexeme-value lexeme)) (read-args ib) ib)
(m4-process ib op)]
[eof #t]
[else (error 'm4-internal "unexpected lexeme ~s" lexeme)]))))
(define name-start-char?
(lambda (c)
(or (char-alphabetic? c)
(char=? c #\_))))
(define name-char?
(lambda (c)
(or (name-start-char? c)
(char-numeric? c))))
(define read-lexeme
(lambda (ib)
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) (cons 'eof c)]
[(char=? c #\#) (cons 'comment (read-comment ib))]
[(char=? c *open-quote*) (cons 'literal (read-quoted ib))]
[(name-start-char? c) (lookup-macro (cons c (read-alpha ib)))]
[else (cons 'literal (string c))]))))
(define read-comment
(lambda (ib)
(let loop ([ls '(#\#)])
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) (list->string (reverse ls))]
[(char=? c #\newline) (list->string (reverse (cons c ls)))]
[else (loop (cons c ls))])))))
(define read-quoted
(lambda (ib)
(let loop ([ls '()] [n 0])
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c)
(error 'm4 "end-of-file detected at quote level ~s" n)]
[(char=? c *close-quote*)
(if (= n 0)
(list->string (reverse ls))
(loop (cons c ls) (- n 1)))]
[(char=? c *open-quote*) (loop (cons c ls) (+ n 1))]
[else (loop (cons c ls) n)])))))
(define read-alpha
(lambda (ib)
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) '()]
[(name-char? c) (cons c (read-alpha ib))]
[else (m4-unget-char c ib) '()]))))
(define lookup-macro
(lambda (ls)
(let ([s (list->string ls)])
(let ([a (assoc s *macros*)])
(if a
(cons 'macro a)
(cons 'literal s))))))
(define read-args
(lambda (ib)
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) '()]
[(char=? c oparen)
(let next-arg ()
(let skip-white ()
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) '()]
[(char-whitespace? c) (skip-white)]
[else (m4-unget-char c ib)])))
(let this-arg ([strings '()])
(let ([c (m4-get-char ib)])
(cond
[(or (eof-object? c) (char=? c cparen))
(if (null? strings)
'()
(cons (apply string-append (reverse strings))
'()))]
[(char=? c oparen)
(let nest ([strings (cons (string oparen)
strings)]
[k this-arg])
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) (this-arg strings)]
[(char=? c cparen)
(k (cons (string cparen) strings))]
[(char=? c oparen)
(nest (cons (string oparen) strings)
(lambda (strings)
(nest strings k)))]
[else
(m4-unget-char c ib)
(let ([lexeme (read-lexeme ib)])
(case (lexeme-type lexeme)
[comment (nest strings k)]
[literal
(nest (cons (lexeme-value lexeme)
strings)
k)]
[macro
((cdr (lexeme-value lexeme))
(read-args ib)
ib)
(nest strings k)]
[else
(error 'm4-internal
"unexpected lexeme ~s"
lexeme)]))])))]
[(char=? c #\,)
(cons (apply string-append (reverse strings))
(next-arg))]
[else
(m4-unget-char c ib)
(let ([lexeme (read-lexeme ib)])
(case (lexeme-type lexeme)
[comment (this-arg strings)]
[literal
(this-arg
(cons (lexeme-value lexeme) strings))]
[macro
((cdr (lexeme-value lexeme)) (read-args ib) ib)
(this-arg strings)]
[else
(error 'm4-internal
"unexpected lexeme ~s"
lexeme)]))]))))]
[else (m4-unget-char c ib) '()]))))
;;; builtin macros
(define $$ (lambda (ls) (if (null? ls) ls (cdr ls))))
(define $1 (lambda (ls) (if (null? ls) "" (car ls))))
(define $2 (lambda (ls) ($1 ($$ ls))))
(define $3 (lambda (ls) ($2 ($$ ls))))
(define $4 (lambda (ls) ($3 ($$ ls))))
(define $5 (lambda (ls) ($4 ($$ ls))))
(define $6 (lambda (ls) ($5 ($$ ls))))
(define $7 (lambda (ls) ($6 ($$ ls))))
(define $8 (lambda (ls) ($7 ($$ ls))))
(define $9 (lambda (ls) ($8 ($$ ls))))
(define-builtin-macro "changequote"
(lambda (args ib)
(set! *open-quote*
(if (string=? ($1 args) "") #\` (string-ref ($1 args) 0)))
(set! *close-quote*
(if (string=? ($2 args) "") #\' (string-ref ($2 args) 0)))))
(define-builtin-macro "define"
(lambda (args ib)
(let ([name ($1 args)])
(unless (let ([n (string-length name)])
(and (fx> n 0)
(name-start-char? (string-ref name 0))
(let ok? ([i 1])
(or (fx= i n)
(and (name-char? (string-ref name i))
(ok? (fx+ i 1)))))))
(error 'm4-define "invalid macro name ~s" name))
(let ([proc (make-macro ($2 args))])
(let ([a (assoc name *macros*)])
(if a
(set-cdr! a proc)
(set! *macros* (cons (cons name proc) *macros*))))))))
(define make-macro
(lambda (s)
(let ([ls (string->list s)])
(lambda (args ib)
(let loop ([ls ls])
(unless (null? ls)
(case (and (char=? (car ls) #\$)
(not (null? (cdr ls)))
(cadr ls))
[#\1 (loop (cddr ls)) (unget-string ($1 args) ib)]
[#\2 (loop (cddr ls)) (unget-string ($2 args) ib)]
[#\3 (loop (cddr ls)) (unget-string ($3 args) ib)]
[#\4 (loop (cddr ls)) (unget-string ($4 args) ib)]
[#\5 (loop (cddr ls)) (unget-string ($5 args) ib)]
[#\6 (loop (cddr ls)) (unget-string ($6 args) ib)]
[#\7 (loop (cddr ls)) (unget-string ($7 args) ib)]
[#\8 (loop (cddr ls)) (unget-string ($8 args) ib)]
[#\9 (loop (cddr ls)) (unget-string ($9 args) ib)]
[else (loop (cdr ls)) (m4-unget-char (car ls) ib)])))))))
(define-builtin-macro "divert"
(lambda (args ib)
(set! *divnum*
(if (string=? ($1 args) "")
0
(case (string-ref ($1 args) 0)
[#\0 0]
[#\1 1]
[#\2 2]
[#\3 3]
[#\4 4]
[#\5 5]
[#\6 6]
[#\7 7]
[#\8 8]
[#\9 9]
[else -1])))
(when (and (<= 1 *divnum* 9) (not (vector-ref *diversions* *divnum*)))
(vector-set! *diversions* *divnum* (open-output-string)))))
(define-builtin-macro "divnum"
(lambda (args ib)
(unget-string (format "~a" *divnum*) ib)))
(define-builtin-macro "dnl"
(lambda (args ib)
(let loop ()
(let ([c (m4-get-char ib)])
(cond
[(eof-object? c) '()]
[(char=? c #\newline) '()]
[else (loop)])))))
(define-builtin-macro "dumpdef"
(lambda (args ib)
(printf "m4 warning: no dumpdef yet~%")))
(define-builtin-macro "errprint"
(lambda (args ib)
(display ($1 args) *error-output*)
(newline *error-output*)))
(define-builtin-macro "eval"
(lambda (args ib)
(unget-string (int->str (eval-string ($1 args))) ib)))
(define-builtin-macro "ifdef"
(lambda (args ib)
(unget-string ((if (assoc ($1 args) *macros*) $2 $3) args) ib)))
(define-builtin-macro "ifelse"
(rec ifelse
(lambda (args ib)
(if (string=? ($1 args) ($2 args))
(unget-string ($3 args) ib)
(if (> (length args) 4)
(ifelse ($$ ($$ ($$ args))) ib)
(unget-string ($4 args) ib))))))
(define-builtin-macro "include"
(lambda (args ib)
(printf "m4 warning: no include yet~%")))
(define-builtin-macro "incr"
(lambda (args ib)
(unget-string (int->str (+ (str->int ($1 args)) 1)) ib)))
(define-builtin-macro "index"
(lambda (args ib)
(let ([s1 ($1 args)] [s2 ($2 args)])
(let ([n1 (string-length s1)] [n2 (string-length s2)])
(let find ([i 0])
(if (fx> n2 (fx- n1 i))
(unget-string "-1" ib)
(let try ([i1 i] [i2 0])
(if (fx= i2 n2)
(unget-string (int->str i) ib)
(if (char=? (string-ref s1 i1) (string-ref s2 i2))
(try (fx+ i1 1) (fx+ i2 1))
(find (fx+ i 1)))))))))))
(define-builtin-macro "len"
(lambda (args ib)
(unget-string (int->str (string-length ($1 args))) ib)))
(define-builtin-macro "maketemp"
(lambda (args ib)
(printf "m4 warning: no maketemp yet~%")))
(define-builtin-macro "shift"
(lambda (args ib)
(printf "m4 warning: no shift yet~%")))
(define-builtin-macro "sinclude"
(lambda (args ib)
(printf "m4 warning: no sinclude yet~%")))
(define-builtin-macro "substr"
(lambda (args ib)
(let ([s ($1 args)] [start ($2 args)] [count ($3 args)])
(let ([n (string-length s)])
(let ([start (min (max (str->int start) 0) n)])
(let ([end (if (string=? count "")
n
(min (max (+ (str->int count) start) start) n))])
(unget-string (substring s start end) ib)))))))
(define-builtin-macro "syscmd"
;;; cannot be written in Scheme---needs something more powerful than
;;; "system" or "process"
(lambda (args ib)
(printf "m4 warning: no syscmd yet~%")))
(define-builtin-macro "translit"
(lambda (args ib)
(let ([s1 ($1 args)] [s2 ($2 args)] [s3 ($3 args)])
(let ([n1 (string-length s1)] [n2 (string-length s2)])
(unless (= n2 (string-length s3))
(error 'm4 "translit arguments ~s and ~s are not of same length"
s2 s3))
(when (null? *translit-table*)
(set! *translit-table* (make-string 256)))
(do ([i 0 (fx+ i 1)])
((fx= i 256))
(string-set! *translit-table* i (integer->char i)))
(do ([i 0 (fx+ i 1)])
((fx= i n2))
(string-set! *translit-table*
(char->integer (string-ref s2 i))
(string-ref s3 i)))
(let ([s4 (make-string n1)])
(do ([i 0 (fx+ i 1)])
((fx= i n1))
(string-set! s4 i
(string-ref *translit-table*
(char->integer (string-ref s1 i)))))
(unget-string s4 ib))))))
(define-builtin-macro "undefine"
(lambda (args ib)
(let ([a (assoc ($1 args) *macros*)])
(unless a (error 'm4 "cannot undefine ~s (not defined)" ($1 args)))
(set-car! a #f))))
(define-builtin-macro "undivert"
(rec myself
(lambda (args ib)
(if (null? args)
(myself '("1" "2" "3" "4" "5" "6" "7" "8" "9") ib)
(for-each
(lambda (x)
(case (and (not (string=? x "")) (string-ref x 0))
[#\1 (undivert 1)]
[#\2 (undivert 2)]
[#\3 (undivert 3)]
[#\4 (undivert 4)]
[#\5 (undivert 5)]
[#\6 (undivert 6)]
[#\7 (undivert 7)]
[#\8 (undivert 8)]
[#\9 (undivert 9)]))
args)))))
(define undivert
(lambda (n)
(let ([op (vector-ref *diversions* n)])
(when op
(display (get-output-string op) (vector-ref *diversions* 0))))))