racket/collects/redex/private/term-fn.rkt
Robby Findler 0369342bfe added names to clauses in define-judgment-form and added
judgment-form-cases to use the names to control typesetting
2012-08-08 21:34:28 -05:00

59 lines
2.2 KiB
Racket

#lang racket/base
(require (for-template racket/base "defined-checks.rkt"))
(provide make-term-fn
term-fn?
term-fn-get-id
(struct-out term-id)
(struct-out judgment-form)
(struct-out defined-term)
defined-term-id?
defined-check
not-expression-context
make-language-id
language-id-nts
pattern-symbols)
(define-values (struct-type make-term-fn term-fn? term-fn-get term-fn-set!)
(make-struct-type 'term-fn #f 1 0))
(define term-fn-get-id (make-struct-field-accessor term-fn-get 0))
(define-struct term-id (id depth))
(define (transformer-predicate p? stx)
(and (identifier? stx)
(cond [(syntax-local-value stx (λ () #f)) => p?]
[else #f])))
(define-struct judgment-form (name mode proc mk-proc lang lws rule-names))
(define-struct defined-term (value))
(define (defined-term-id? stx)
(transformer-predicate defined-term? stx))
(define (defined-check id desc #:external [external id])
(if (eq? (identifier-binding id) 'lexical)
(quasisyntax/loc external (check-defined-lexical #,id '#,external #,desc))
(quasisyntax/loc external (check-defined-module (λ () #,id) '#,external #,desc))))
(define (not-expression-context stx)
(when (eq? (syntax-local-context) 'expression)
(raise-syntax-error #f "not allowed in an expression context" stx)))
(define-values (language-id make-language-id language-id? language-id-get language-id-set) (make-struct-type 'language-id #f 2 0 #f '() #f 0))
(define (language-id-nts stx id) (language-id-getter stx id 1))
(define (language-id-getter stx id n)
(unless (identifier? stx)
(raise-syntax-error id "expected an identifier defined by define-language" stx))
(let ([val (syntax-local-value stx (λ () #f))])
(unless (and (set!-transformer? val)
(language-id? (set!-transformer-procedure val)))
(raise-syntax-error id "expected an identifier defined by define-language" stx))
(language-id-get (set!-transformer-procedure val) n)))
(define pattern-symbols '(any number natural integer real string variable
variable-not-otherwise-mentioned hole symbol))