conservatory
/
picrin
4
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

syntax-rules: support splicing in template

This commit is contained in:
Yuichi Nishiwaki 2015-06-15 02:12:56 +09:00
parent 691d0ad698
commit af59885858
1 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
piclib/picrin/syntax-rules.scm
View File

@ -49,6 +49,12 @@
;; | (p . p)
;; | (p ...)
;; only template supports (p ... . p) pattern
;; tp := constant
;; | var
;; | (p . p)
;; | (p ... . p)
(define (compile ellipsis literals rules)
(define (constant? obj)
@ -63,8 +69,7 @@
(and (pair? pat)
(pair? (cdr pat))
(variable? (cadr pat))
(variable=? (cadr pat) ellipsis)
(eq? (cddr pat) '())))
(variable=? (cadr pat) ellipsis)))
(define (pattern-validator pat) ; pattern -> validator
(letrec
@ -166,7 +171,9 @@
;; ((a . (x1 x2)) (b . (y1 y2 y3)) (c . z1)) -> ((x1 x2) (y1 y2 y3) (z1))
(list-of-selectors
(map (lambda (x) (if (list? x) x (list x))) (map cdr filtered-selectors))))
#`(map (lambda #,inner-tmps #,inner-rep) #,@list-of-selectors)))
(let ((rep1 #`(map (lambda #,inner-tmps #,inner-rep) #,@list-of-selectors))
(rep2 (template-representation (cddr pat) levels selectors)))
#`(append #,rep1 #,rep2))))
((pair? pat)
#`(cons #,(template-representation (car pat) levels selectors)
#,(template-representation (cdr pat) levels selectors)))))