using ER let-keyword-form, removing match dependency

This commit is contained in:
Alex Shinn 2009-12-12 16:58:31 +09:00
parent d2e094e4c1
commit 3d02285732
2 changed files with 35 additions and 75 deletions

View file

@ -5,6 +5,5 @@
summing multiplying in-string in-string-reverse
in-vector in-vector-reverse)
(import (scheme))
(import (chibi match))
(include "loop/loop.scm"))

View file

@ -9,83 +9,44 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (assoc-pred equal elt ls)
(and (pair? ls)
(if (equal elt (car (car ls)))
(car ls)
(assoc-pred equal elt (cdr ls)))))
(define-syntax let-keyword-form
(syntax-rules ()
((let-keyword-form
((labeled-arg-macro-name
(positional-form-name (arg-name . arg-default) ...)))
((labeled-arg-macro-name (positional-name . params)))
. body)
(letrec-syntax
(let-syntax
((labeled-arg-macro-name
(syntax-rules ()
((labeled-arg-macro-name . keyword-val-pairs)
(letrec-syntax
((find
(syntax-rules (=> arg-name ...)
((find kvp k-args (arg-name . default) (=> arg-name val)
. others) ; found arg-name among keyword-val-pairs
(next kvp val . k-args)) ...
((find kvp k-args key (=> arg-no-match-name val) . others)
(find kvp k-args key . others))
;; default must be here
((find kvp k-args (arg-name default))
(next kvp default . k-args)) ...
))
(next ; pack the continuation to find
(syntax-rules ()
((next kvp val vals key . keys)
(find kvp ((val . vals) . keys) key . kvp))
((next kvp val vals) ; processed all arg-descriptors
(rev-apply (val) vals))))
(match-positionals
(syntax-rules (=>)
((match-positionals () res . rest)
(rev-apply () res))
((match-positionals args (val . vals) (=> name value)
. rest)
(next ((=> name value) . rest) val vals . args))
((match-positionals args (val . vals))
(next () val vals . args))
((match-positionals (arg1 . args) res pos-arg . rest)
(match-positionals args (pos-arg . res) . rest))))
(rev-apply
(syntax-rules ()
((rev-apply form (x . xs))
(rev-apply (x . form) xs))
((rev-apply form ()) form))))
(match-positionals ((arg-name . arg-default) ...)
(positional-form-name)
. keyword-val-pairs)
)))))
(er-macro-transformer
(lambda (expr rename compare)
(let lp ((ls (cdr expr)) (named '()) (posns '()))
(cond
((pair? ls)
(if (and (list? (car ls)) (compare (caar ls) (rename '=>)))
(lp (cdr ls) (cons (cdar ls) named) posns)
(lp (cdr ls) named (cons (car ls) posns))))
(else
(let lp ((ls (syntax-quote params))
(posns (reverse posns))
(args '()))
(cond
((null? ls)
(if (pair? posns)
(error "let-keyword-form: too many args" expr)
(cons (syntax-quote positional-name) (reverse args))))
((assoc-pred compare (caar ls) named)
=> (lambda (x) (lp (cdr ls) posns (cons (cadr x) args))))
((pair? posns)
(lp (cdr ls) (cdr posns) (cons (car posns) args)))
(else
(lp (cdr ls) posns (cons (cadar ls) args))))))))))))
. body))))
;; (define-syntax let-keyword-form
;; (syntax-rules ()
;; ((let-keyword-form
;; ((labeled-arg-macro-name (positional-name (arg default) ...)))
;; . body)
;; (letrec-syntax
;; ((labeled-arg-macro-name
;; (er-macro-transformer
;; (lambda (expr rename compare)
;; (receive (named posns)
;; (partition (lambda (x) (and (list? x) (compare (car x) (rename '=>))))
;; (cdr expr))
;; (let lp ((ls '((arg default) ...)) (posns posns) (args '()))
;; (cond
;; ((null? ls)
;; (if (pair? posns)
;; (error "let-keyword-form: too many args" expr)
;; (cons 'positional-name (reverse args))))
;; ((find (lambda (x) (compare (caar ls) (cadr x))) named)
;; => (lambda (x)
;; (lp (cdr ls) posns (cons (caddr x) args))))
;; ((pair? posns)
;; (lp (cdr ls) (cdr posns) (cons (car posns) args)))
;; (else
;; (lp (cdr ls) posns (cons (cadar ls) args))))))))))
;; . body))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define-syntax loop
@ -137,8 +98,8 @@
(letrec ((tmp (lambda (var ...)
(if (or checks ...)
(let-keyword-form ((name (tmp (var step) ...)))
(match-let (finals ...) result))
(match-let (refs ...)
(let (finals ...) result))
(let (refs ...)
(let-keyword-form ((name (tmp (var step) ...)))
(if #f #f)
. body))))))
@ -380,8 +341,8 @@
((listing-reverse args next . rest)
(accumulating (cons (lambda (x) x) '()) args next . rest))))
(define (append-reverse ls1 ls2)
(append (reverse ls1) ls2))
(define (append-reverse rev tail)
(if (null? rev) tail (append-reverse (cdr rev) (cons (car rev) tail))))
(define-syntax appending
(syntax-rules ()