From 97297221faa3430789e91a0f85135dad50e119f8 Mon Sep 17 00:00:00 2001 From: Alex Shinn Date: Wed, 2 Mar 2016 23:34:39 +0900 Subject: [PATCH] When an alternate syntax-rules ellipsis is specified, we must bind this locally around the macro transformer. Fixes issue #313. --- lib/init-7.scm | 453 +++++++++++++++++++++-------------------- tests/syntax-tests.scm | 11 + 2 files changed, 242 insertions(+), 222 deletions(-) diff --git a/lib/init-7.scm b/lib/init-7.scm index 5ae72c0f..63e133af 100644 --- a/lib/init-7.scm +++ b/lib/init-7.scm @@ -669,231 +669,240 @@ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; syntax-rules +(define (syntax-rules-transformer expr rename compare) + (let ((ellipsis-specified? (identifier? (cadr expr))) + (count 0) + (_er-macro-transformer (rename 'er-macro-transformer)) + (_lambda (rename 'lambda)) (_let (rename 'let)) + (_begin (rename 'begin)) (_if (rename 'if)) + (_and (rename 'and)) (_or (rename 'or)) + (_eq? (rename 'eq?)) (_equal? (rename 'equal?)) + (_car (rename 'car)) (_cdr (rename 'cdr)) + (_cons (rename 'cons)) (_pair? (rename 'pair?)) + (_null? (rename 'null?)) (_expr (rename 'expr)) + (_rename (rename 'rename)) (_compare (rename 'compare)) + (_quote (rename 'syntax-quote)) (_apply (rename 'apply)) + (_append (rename 'append)) (_map (rename 'map)) + (_vector? (rename 'vector?)) (_list? (rename 'list?)) + (_len (rename'len)) (_length (rename 'length*)) + (_- (rename '-)) (_>= (rename '>=)) (_error (rename 'error)) + (_ls (rename 'ls)) (_res (rename 'res)) (_i (rename 'i)) + (_reverse (rename 'reverse)) + (_vector->list (rename 'vector->list)) + (_list->vector (rename 'list->vector)) + (_cons3 (rename 'cons-source))) + (define ellipsis (if ellipsis-specified? (cadr expr) '...)) + (define lits (if ellipsis-specified? (car (cddr expr)) (cadr expr))) + (define forms (if ellipsis-specified? (cdr (cddr expr)) (cddr expr))) + (define (next-symbol s) + (set! count (+ count 1)) + (rename (string->symbol (string-append s (%number->string count))))) + (define (expand-pattern pat tmpl) + (let lp ((p (cdr pat)) + (x (list _cdr _expr)) + (dim 0) + (vars '()) + (k (lambda (vars) + (list _cons (expand-template tmpl vars) #f)))) + (let ((v (next-symbol "v."))) + (list + _let (list (list v x)) + (cond + ((identifier? p) + (if (any (lambda (l) (compare p l)) lits) + (list _and + (list _compare v (list _rename (list _quote p))) + (k vars)) + (list _let (list (list p v)) (k (cons (cons p dim) vars))))) + ((ellipsis? p) + (cond + ((not (null? (cdr (cdr p)))) + (cond + ((any (lambda (x) (and (identifier? x) (compare x ellipsis))) + (cddr p)) + (error "multiple ellipses" p)) + (else + (let ((len (length* (cdr (cdr p)))) + (_lp (next-symbol "lp."))) + `(,_let ((,_len (,_length ,v))) + (,_and (,_>= ,_len ,len) + (,_let ,_lp ((,_ls ,v) + (,_i (,_- ,_len ,len)) + (,_res (,_quote ()))) + (,_if (,_>= 0 ,_i) + ,(lp `(,(cddr p) + (,(car p) ,(car (cdr p)))) + `(,_cons ,_ls + (,_cons (,_reverse ,_res) + (,_quote ()))) + dim + vars + k) + (,_lp (,_cdr ,_ls) + (,_- ,_i 1) + (,_cons3 (,_car ,_ls) + ,_res + ,_ls)))))))))) + ((identifier? (car p)) + (list _and (list _list? v) + (list _let (list (list (car p) v)) + (k (cons (cons (car p) (+ 1 dim)) vars))))) + (else + (let* ((w (next-symbol "w.")) + (_lp (next-symbol "lp.")) + (new-vars (all-vars (car p) (+ dim 1))) + (ls-vars (map (lambda (x) + (next-symbol + (string-append + (symbol->string + (identifier->symbol (car x))) + "-ls"))) + new-vars)) + (once + (lp (car p) (list _car w) (+ dim 1) '() + (lambda (_) + (cons + _lp + (cons + (list _cdr w) + (map (lambda (x l) + (list _cons (car x) l)) + new-vars + ls-vars))))))) + (list + _let + _lp (cons (list w v) + (map (lambda (x) (list x (list _quote '()))) ls-vars)) + (list _if (list _null? w) + (list _let (map (lambda (x l) + (list (car x) (list _reverse l))) + new-vars + ls-vars) + (k (append new-vars vars))) + (list _and (list _pair? w) once))))))) + ((pair? p) + (list _and (list _pair? v) + (lp (car p) + (list _car v) + dim + vars + (lambda (vars) + (lp (cdr p) (list _cdr v) dim vars k))))) + ((vector? p) + (list _and + (list _vector? v) + (lp (vector->list p) (list _vector->list v) dim vars k))) + ((null? p) (list _and (list _null? v) (k vars))) + (else (list _and (list _equal? v p) (k vars)))))))) + (define (ellipsis-escape? x) (and (pair? x) (compare ellipsis (car x)))) + (define (ellipsis? x) + (and (pair? x) (pair? (cdr x)) (compare ellipsis (cadr x)))) + (define (ellipsis-depth x) + (if (ellipsis? x) + (+ 1 (ellipsis-depth (cdr x))) + 0)) + (define (ellipsis-tail x) + (if (ellipsis? x) + (ellipsis-tail (cdr x)) + (cdr x))) + (define (all-vars x dim) + (let lp ((x x) (dim dim) (vars '())) + (cond ((identifier? x) + (if (any (lambda (lit) (compare x lit)) lits) + vars + (cons (cons x dim) vars))) + ((ellipsis? x) (lp (car x) (+ dim 1) (lp (cddr x) dim vars))) + ((pair? x) (lp (car x) dim (lp (cdr x) dim vars))) + ((vector? x) (lp (vector->list x) dim vars)) + (else vars)))) + (define (free-vars x vars dim) + (let lp ((x x) (free '())) + (cond + ((identifier? x) + (if (and (not (memq x free)) + (cond ((assq x vars) => (lambda (cell) (>= (cdr cell) dim))) + (else #f))) + (cons x free) + free)) + ((pair? x) (lp (car x) (lp (cdr x) free))) + ((vector? x) (lp (vector->list x) free)) + (else free)))) + (define (expand-template tmpl vars) + (let lp ((t tmpl) (dim 0)) + (cond + ((identifier? t) + (cond + ((find (lambda (v) (compare t (car v))) vars) + => (lambda (cell) + (if (<= (cdr cell) dim) + t + (error "too few ...'s")))) + (else + (list _rename (list _quote t))))) + ((pair? t) + (cond + ((ellipsis-escape? t) + (list _quote + (if (pair? (cdr t)) + (if (pair? (cddr t)) (cddr t) (cadr t)) + (cdr t)))) + ((ellipsis? t) + (let* ((depth (ellipsis-depth t)) + (ell-dim (+ dim depth)) + (ell-vars (free-vars (car t) vars ell-dim))) + (cond + ((null? ell-vars) + (error "too many ...'s")) + ((and (null? (cdr (cdr t))) (identifier? (car t))) + ;; shortcut for (var ...) + (lp (car t) ell-dim)) + (else + (let* ((once (lp (car t) ell-dim)) + (nest (if (and (null? (cdr ell-vars)) + (identifier? once) + (eq? once (car vars))) + once ;; shortcut + (cons _map + (cons (list _lambda ell-vars once) + ell-vars)))) + (many (do ((d depth (- d 1)) + (many nest + (list _apply _append many))) + ((= d 1) many)))) + (if (null? (ellipsis-tail t)) + many ;; shortcut + (list _append many (lp (ellipsis-tail t) dim)))))))) + (else (list _cons3 (lp (car t) dim) (lp (cdr t) dim) (list _quote t))))) + ((vector? t) (list _list->vector (lp (vector->list t) dim))) + ((null? t) (list _quote '())) + (else t)))) + (list + _er-macro-transformer + (list _lambda (list _expr _rename _compare) + (list + _car + (cons + _or + (append + (map + (lambda (clause) (expand-pattern (car clause) (cadr clause))) + forms) + (list + (list _cons + (list _error "no expansion for" + (list (rename 'strip-syntactic-closures) _expr)) + #f))))))))) + +(define-syntax syntax-rules/aux + (er-macro-transformer syntax-rules-transformer)) + (define-syntax syntax-rules (er-macro-transformer (lambda (expr rename compare) - (let ((ellipsis-specified? (identifier? (cadr expr))) - (count 0) - (_er-macro-transformer (rename 'er-macro-transformer)) - (_lambda (rename 'lambda)) (_let (rename 'let)) - (_begin (rename 'begin)) (_if (rename 'if)) - (_and (rename 'and)) (_or (rename 'or)) - (_eq? (rename 'eq?)) (_equal? (rename 'equal?)) - (_car (rename 'car)) (_cdr (rename 'cdr)) - (_cons (rename 'cons)) (_pair? (rename 'pair?)) - (_null? (rename 'null?)) (_expr (rename 'expr)) - (_rename (rename 'rename)) (_compare (rename 'compare)) - (_quote (rename 'syntax-quote)) (_apply (rename 'apply)) - (_append (rename 'append)) (_map (rename 'map)) - (_vector? (rename 'vector?)) (_list? (rename 'list?)) - (_len (rename'len)) (_length (rename 'length*)) - (_- (rename '-)) (_>= (rename '>=)) (_error (rename 'error)) - (_ls (rename 'ls)) (_res (rename 'res)) (_i (rename 'i)) - (_reverse (rename 'reverse)) - (_vector->list (rename 'vector->list)) - (_list->vector (rename 'list->vector)) - (_cons3 (rename 'cons-source))) - (define ellipsis (if ellipsis-specified? (cadr expr) (rename '...))) - (define lits (if ellipsis-specified? (car (cddr expr)) (cadr expr))) - (define forms (if ellipsis-specified? (cdr (cddr expr)) (cddr expr))) - (define (next-symbol s) - (set! count (+ count 1)) - (rename (string->symbol (string-append s (%number->string count))))) - (define (expand-pattern pat tmpl) - (let lp ((p (cdr pat)) - (x (list _cdr _expr)) - (dim 0) - (vars '()) - (k (lambda (vars) - (list _cons (expand-template tmpl vars) #f)))) - (let ((v (next-symbol "v."))) - (list - _let (list (list v x)) - (cond - ((identifier? p) - (if (any (lambda (l) (compare p l)) lits) - (list _and - (list _compare v (list _rename (list _quote p))) - (k vars)) - (list _let (list (list p v)) (k (cons (cons p dim) vars))))) - ((ellipsis? p) - (cond - ((not (null? (cdr (cdr p)))) - (cond - ((any (lambda (x) (and (identifier? x) (compare x ellipsis))) - (cddr p)) - (error "multiple ellipses" p)) - (else - (let ((len (length* (cdr (cdr p)))) - (_lp (next-symbol "lp."))) - `(,_let ((,_len (,_length ,v))) - (,_and (,_>= ,_len ,len) - (,_let ,_lp ((,_ls ,v) - (,_i (,_- ,_len ,len)) - (,_res (,_quote ()))) - (,_if (,_>= 0 ,_i) - ,(lp `(,(cddr p) - (,(car p) ,(car (cdr p)))) - `(,_cons ,_ls - (,_cons (,_reverse ,_res) - (,_quote ()))) - dim - vars - k) - (,_lp (,_cdr ,_ls) - (,_- ,_i 1) - (,_cons3 (,_car ,_ls) - ,_res - ,_ls)))))))))) - ((identifier? (car p)) - (list _and (list _list? v) - (list _let (list (list (car p) v)) - (k (cons (cons (car p) (+ 1 dim)) vars))))) - (else - (let* ((w (next-symbol "w.")) - (_lp (next-symbol "lp.")) - (new-vars (all-vars (car p) (+ dim 1))) - (ls-vars (map (lambda (x) - (next-symbol - (string-append - (symbol->string - (identifier->symbol (car x))) - "-ls"))) - new-vars)) - (once - (lp (car p) (list _car w) (+ dim 1) '() - (lambda (_) - (cons - _lp - (cons - (list _cdr w) - (map (lambda (x l) - (list _cons (car x) l)) - new-vars - ls-vars))))))) - (list - _let - _lp (cons (list w v) - (map (lambda (x) (list x (list _quote '()))) ls-vars)) - (list _if (list _null? w) - (list _let (map (lambda (x l) - (list (car x) (list _reverse l))) - new-vars - ls-vars) - (k (append new-vars vars))) - (list _and (list _pair? w) once))))))) - ((pair? p) - (list _and (list _pair? v) - (lp (car p) - (list _car v) - dim - vars - (lambda (vars) - (lp (cdr p) (list _cdr v) dim vars k))))) - ((vector? p) - (list _and - (list _vector? v) - (lp (vector->list p) (list _vector->list v) dim vars k))) - ((null? p) (list _and (list _null? v) (k vars))) - (else (list _and (list _equal? v p) (k vars)))))))) - (define (ellipsis-escape? x) (and (pair? x) (compare ellipsis (car x)))) - (define (ellipsis? x) - (and (pair? x) (pair? (cdr x)) (compare ellipsis (cadr x)))) - (define (ellipsis-depth x) - (if (ellipsis? x) - (+ 1 (ellipsis-depth (cdr x))) - 0)) - (define (ellipsis-tail x) - (if (ellipsis? x) - (ellipsis-tail (cdr x)) - (cdr x))) - (define (all-vars x dim) - (let lp ((x x) (dim dim) (vars '())) - (cond ((identifier? x) - (if (any (lambda (lit) (compare x lit)) lits) - vars - (cons (cons x dim) vars))) - ((ellipsis? x) (lp (car x) (+ dim 1) (lp (cddr x) dim vars))) - ((pair? x) (lp (car x) dim (lp (cdr x) dim vars))) - ((vector? x) (lp (vector->list x) dim vars)) - (else vars)))) - (define (free-vars x vars dim) - (let lp ((x x) (free '())) - (cond - ((identifier? x) - (if (and (not (memq x free)) - (cond ((assq x vars) => (lambda (cell) (>= (cdr cell) dim))) - (else #f))) - (cons x free) - free)) - ((pair? x) (lp (car x) (lp (cdr x) free))) - ((vector? x) (lp (vector->list x) free)) - (else free)))) - (define (expand-template tmpl vars) - (let lp ((t tmpl) (dim 0)) - (cond - ((identifier? t) - (cond - ((find (lambda (v) (compare t (car v))) vars) - => (lambda (cell) - (if (<= (cdr cell) dim) - t - (error "too few ...'s")))) - (else - (list _rename (list _quote t))))) - ((pair? t) - (cond - ((ellipsis-escape? t) - (list _quote - (if (pair? (cdr t)) - (if (pair? (cddr t)) (cddr t) (cadr t)) - (cdr t)))) - ((ellipsis? t) - (let* ((depth (ellipsis-depth t)) - (ell-dim (+ dim depth)) - (ell-vars (free-vars (car t) vars ell-dim))) - (cond - ((null? ell-vars) - (error "too many ...'s")) - ((and (null? (cdr (cdr t))) (identifier? (car t))) - ;; shortcut for (var ...) - (lp (car t) ell-dim)) - (else - (let* ((once (lp (car t) ell-dim)) - (nest (if (and (null? (cdr ell-vars)) - (identifier? once) - (eq? once (car vars))) - once ;; shortcut - (cons _map - (cons (list _lambda ell-vars once) - ell-vars)))) - (many (do ((d depth (- d 1)) - (many nest - (list _apply _append many))) - ((= d 1) many)))) - (if (null? (ellipsis-tail t)) - many ;; shortcut - (list _append many (lp (ellipsis-tail t) dim)))))))) - (else (list _cons3 (lp (car t) dim) (lp (cdr t) dim) (list _quote t))))) - ((vector? t) (list _list->vector (lp (vector->list t) dim))) - ((null? t) (list _quote '())) - (else t)))) - (list - _er-macro-transformer - (list _lambda (list _expr _rename _compare) - (list - _car - (cons - _or - (append - (map - (lambda (clause) (expand-pattern (car clause) (cadr clause))) - forms) - (list - (list _cons - (list _error "no expansion for" - (list (rename 'strip-syntactic-closures) _expr)) - #f))))))))))) + (if (identifier? (cadr expr)) + (list (rename 'let) (list (list (cadr expr) #t)) + (cons (rename 'syntax-rules/aux) (cdr expr))) + (syntax-rules-transformer expr rename compare))))) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; additional syntax diff --git a/tests/syntax-tests.scm b/tests/syntax-tests.scm index 04f61a30..e90f4ce8 100644 --- a/tests/syntax-tests.scm +++ b/tests/syntax-tests.scm @@ -57,4 +57,15 @@ ((N y E2) (quote (y E2))))) (test '(1 2 3) (N 1 2 3))) +(define-syntax ell + (syntax-rules () + ((ell body) + (define-syntax emm + (syntax-rules ...1 () + ((emm) body)))))) + +(ell + (define-syntax enn + (syntax-rules ...1 () ((enn args ...1) (quote (args ...1)))))) + (test-end)