You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
149 lines
5.4 KiB
Racket
149 lines
5.4 KiB
Racket
#lang racket/base
|
|
(require (for-syntax racket/base syntax/parse racket/syntax syntax/strip-context)
|
|
syntax/strip-context racket/function)
|
|
(provide (all-defined-out) (all-from-out syntax/strip-context))
|
|
|
|
|
|
(define-syntax (syntax-match stx)
|
|
(syntax-case stx (syntax)
|
|
[(_ stx-arg [(syntax pattern) body ...] ...)
|
|
#'(syntax-case stx-arg ()
|
|
[pattern body ...] ...)]))
|
|
|
|
(define-syntax (add-syntax stx)
|
|
;; todo: permit mixing of two-arg and one-arg binding forms
|
|
;; one-arg form allows you to inject an existing syntax object using its current name
|
|
(syntax-case stx (syntax)
|
|
[(_ ([(syntax sid) sid-stx] ...) body ...)
|
|
#'(with-syntax ([sid sid-stx] ...) body ...)]
|
|
;; todo: limit `sid` to be an identifier
|
|
[(_ ([sid] ...) body ...)
|
|
#'(with-syntax ([sid sid] ...) body ...)]))
|
|
|
|
(define-syntax syntax-let (make-rename-transformer #'add-syntax))
|
|
|
|
(define-syntax inject-syntax (make-rename-transformer #'add-syntax))
|
|
|
|
(define-syntax (map-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))])
|
|
(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))
|
|
|
|
(define (context stx)
|
|
(hash-ref (syntax-debug-info stx) 'context))
|
|
|
|
(define-syntax-rule (scopes stx)
|
|
(format "~a = ~a" 'stx
|
|
(cons (syntax->datum stx)
|
|
(for/list ([scope (in-list (context stx))])
|
|
scope))))
|
|
|
|
(define (->syntax x)
|
|
(if (syntax? x) x (datum->syntax #f x)))
|
|
|
|
|
|
(define-syntax (define-scope stx)
|
|
(syntax-case stx ()
|
|
[(_ 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)]
|
|
[(scope-id-sis ...) (map (λ(sid) (format-id sid "~a-sis" sid)) (syntax->list #'scope-ids))])
|
|
#'(begin
|
|
(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 (add-id (datum->syntax #f '_)) (->syntax x)))
|
|
(define (id? x)
|
|
(and
|
|
(member (car (context (add-id (datum->syntax #f '_))))
|
|
(context (->syntax x)))
|
|
#t))))]))
|
|
|
|
|
|
(define (scopes-equal? stxl stxr)
|
|
;; "A bound-identifier=? comparison checks that two identifiers have exactly the same scope sets"
|
|
(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
|
|
|
|
|
|
(define-scope purple (red blue))
|
|
|
|
(check-true (purple? (add-purple stx)))
|
|
(check-true (scopes-equal? (purple (green stx)) (add-blue (remove-green (add-red (add-green (add-blue stx))))))))
|
|
|
|
|
|
(define-syntax (with-scopes stx)
|
|
(syntax-case stx (syntax)
|
|
[(_ (scope-id) (syntax expr))
|
|
#'(scope-id expr)]))
|