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scope composition

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pull/2/head
Matthew Butterick 8 years ago
parent 99951f2f07
commit 0a5ef3e4dc
1 changed files with 79 additions and 53 deletions
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132
beautiful-racket-lib/br/syntax.rkt
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@ -1,5 +1,5 @@
#lang racket/base
(require (for-syntax racket/base syntax/parse racket/syntax) syntax/strip-context)
(require (for-syntax racket/base syntax/parse racket/syntax) syntax/strip-context racket/function)
(provide (all-defined-out) (all-from-out syntax/strip-context))
@ -25,10 +25,25 @@
(define-syntax (map-syntax stx)
(syntax-case stx ()
[(_ <proc> <arg> ...)
#'(map <proc> (if (and (syntax? <arg>) (list? (syntax-e <arg>)))
(syntax->list <arg>)
<arg>) ...)]))
[(_ _proc _args)
#'(let ([args _args])
(datum->syntax args
(if (and (syntax? args) (list? (syntax-e args)))
(for/list ([arg (in-list (syntax->list args))])
(datum->syntax arg (_proc (syntax->datum arg))))
(error 'not-syntax-list))))]))
(define-syntax (filter-syntax stx)
(syntax-case stx ()
[(_ _proc _args)
#'(let ([args _args])
(datum->syntax args
(if (and (syntax? args) (list? (syntax-e args)))
(for*/list ([arg (in-list (syntax->list args))]
[result (in-value (_proc (syntax->datum arg)))]
#:when result)
arg)
(error 'not-syntax-list))))]))
#;(define-syntax syntax-variable (make-rename-transformer #'format-id))
@ -48,24 +63,34 @@
(define-syntax (define-scope stx)
(syntax-case stx ()
[(_ id)
#'(define-scope id #f)]
[(_ id sis)
(with-syntax ([id-si (format-id #'id "~a-si" #'id)]
#'(define-scope id ())]
[(_ id scope-ids)
(with-syntax ([id-sis (format-id #'id "~a-sis" #'id)]
[add-id (format-id #'id "add-~a" #'id)]
[flip-id (format-id #'id "flip-~a" #'id)]
[remove-id (format-id #'id "remove-~a" #'id)]
[id? (format-id #'id "~a?" #'id)]
[id* (format-id #'id "~a*" #'id)])
[id* (format-id #'id "~a*" #'id)]
[(scope-id-sis ...) (map (λ(scope-id) (format-id scope-id "~a-sis" scope-id)) (syntax->list #'scope-ids))])
#'(begin
(define id-si (or sis (make-syntax-introducer 'use-site)))
(define add-id (λ(x) (id-si (->syntax x) 'add)))
(define flip-id (λ(x) (id-si (->syntax x) 'flip)))
(define remove-id (λ(x) (id-si (->syntax x) 'remove)))
(local-require sugar/debug)
(define id-sis
(let ([sis-in (list scope-id-sis ...)])
(if (pair? sis-in)
(apply append sis-in)
(list
(let ([si (make-syntax-introducer 'use-site)])
(list (procedure-rename (curryr si 'add) 'add-id)
(procedure-rename (curryr si 'flip) 'flip-id)
(procedure-rename (curryr si 'remove) 'remove-id)))))))
(define add-id (λ(x) ((apply compose1 (map car id-sis)) (->syntax x))))
(define flip-id (λ(x) ((apply compose1 (map cadr id-sis)) (->syntax x))))
(define remove-id (λ(x) ((apply compose1 (map caddr id-sis)) (->syntax x))))
(define (id x) (add-id (datum->syntax #f (syntax-e (->syntax x)))))
(define (id* x) (replace-context (id-si (datum->syntax #f '_)) (->syntax x)))
(define (id* x) (replace-context (add-id (datum->syntax #f '_)) (->syntax x)))
(define (id? x)
(and
(member (car (context (id-si (datum->syntax #f '_))))
(member (car (context (add-id (datum->syntax #f '_))))
(context (->syntax x)))
#t))))]))
@ -75,44 +100,45 @@
(bound-identifier=? (datum->syntax stxl '_) (datum->syntax stxr '_)))
(module+ test
(require rackunit)
(define-scope red)
(define stx (datum->syntax #f 'x))
(define red-stx (add-red stx))
(define double-red-stx (add-red (add-red stx)))
(check-false (red? stx))
(check-true (red? red-stx))
(check-true (red? double-red-stx))
(check-false (scopes-equal? stx red-stx))
(check-true (scopes-equal? red-stx double-red-stx))
(check-false (scopes-equal? red-stx (remove-red double-red-stx)))
(define-scope blue) ; scope addition is commutative
(define blue-stx (blue stx))
(check-true (scopes-equal? (add-blue red-stx) (add-red blue-stx)))
(check-true (scopes-equal? (remove-red (add-blue red-stx)) (remove-red (add-red blue-stx))))
(define-scope green) ; replace scopes at outer layer
(check-true (scopes-equal? (green red-stx) (green blue-stx)))
;; replace scopes everywhere
(check-true (scopes-equal? (car (syntax->list (green* #`(#,blue-stx #,red-stx))))
(car (syntax->list (green* #`(#,red-stx #,blue-stx))))))
;; todo: test flipping
;; todo: scope composition
#;(define-scope purple (red blue))
#;(check-true (purple? (add-purple stx)))
#;(scopes-equal? (purple stx) (blue (red stx)))
)
(require rackunit)
(define-scope red)
(define stx (datum->syntax #f 'x))
(define red-stx (add-red stx))
(define double-red-stx (add-red (add-red stx)))
(check-false (red? stx))
(check-true (red? red-stx))
(check-true (red? double-red-stx))
(check-false (scopes-equal? stx red-stx))
(check-true (scopes-equal? red-stx double-red-stx))
(check-false (scopes-equal? red-stx (remove-red double-red-stx)))
(define-scope blue) ; scope addition is commutative
(define blue-stx (blue stx))
(check-true (scopes-equal? (add-blue red-stx) (add-red blue-stx)))
(check-true (scopes-equal? (remove-red (add-blue red-stx)) (remove-red (add-red blue-stx))))
(define-scope green) ; replace scopes at outer layer
(check-true (scopes-equal? (green red-stx) (green blue-stx)))
;; replace scopes everywhere
(check-true (scopes-equal? (car (syntax->list (green* #`(#,blue-stx #,red-stx))))
(car (syntax->list (green* #`(#,red-stx #,blue-stx))))))
;; todo: test flipping
(define-scope purple (red blue))
(check-true (purple? (add-purple stx)))
(check-true (scopes-equal? (purple stx) (add-blue (red stx))))
(define-syntax (define-with-scopes stx)
(syntax-case stx ()

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