racket/collects/unstable/syntax.rkt
2012-08-22 11:31:22 -04:00

106 lines
3.3 KiB
Racket

#lang racket/base
;; owner: ryanc (and cce and stamourv, where noted)
(require racket/syntax
syntax/stx
(for-syntax racket/base)
(for-template racket/base))
(provide (rename-out [stx-map syntax-map])
;; by cce:
syntax-source-file-name
syntax-source-directory
;; by stamourv:
format-unique-id
syntax-within?
;; by ryanc
explode-module-path-index
phase-of-enclosing-module
make-variable-like-transformer)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; By Carl Eastlund, below
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Syntax Locations
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (syntax-source-directory stx)
(let* ([source (syntax-source stx)])
(and (path-string? source)
(let-values ([(base file dir?) (split-path source)])
(and (path? base)
(path->complete-path base
(or (current-load-relative-directory)
(current-directory))))))))
(define (syntax-source-file-name stx)
(let* ([f (syntax-source stx)])
(and (path-string? f)
(let-values ([(base file dir?) (split-path f)]) file))))
;; by stamourv:
(define (format-unique-id lctx
#:source [src #f]
#:props [props #f]
#:cert [cert #f]
fmt . args)
((make-syntax-introducer) (apply format-id
lctx #:source src #:props props #:cert cert
fmt args)))
;; is syntax a contained within syntax b, inclusively
(define (syntax-within? a b)
(let ([pos-a (syntax-position a)]
[span-a (syntax-span a)]
[pos-b (syntax-position b)]
[span-b (syntax-span b)])
(and pos-a span-a pos-b span-b
(<= pos-b pos-a)
(>= (+ pos-b span-b) (+ pos-a span-a)))))
;; by ryanc
(define (explode-module-path-index mpi)
(let-values ([(x y) (module-path-index-split mpi)])
(cons x
(if (module-path-index? y)
(explode-module-path-index y)
(list y)))))
(define-syntax-rule (phase-of-enclosing-module)
(variable-reference->module-base-phase
(#%variable-reference)))
(define (make-variable-like-transformer ref-stx [set!-handler #f])
(unless (syntax? ref-stx)
(raise-type-error 'make-variable-like-transformer "syntax?" ref-stx))
(unless (or (syntax? set!-handler) (procedure? set!-handler) (eq? set!-handler #f))
(raise-type-error 'make-variable-like-transformer "(or/c syntax? procedure? #f)" set!-handler))
(make-set!-transformer
(lambda (stx)
(syntax-case stx (set!)
[id
(identifier? #'id)
ref-stx]
[(set! id val)
(cond [(procedure? set!-handler)
(set!-handler stx)]
[(syntax? set!-handler)
(with-syntax ([setter set!-handler])
(syntax/loc stx (setter val)))]
[else
(raise-syntax-error #f "cannot mutate identifier" stx #'id)])]
[(id . args)
(let ([stx* (cons #'(#%expression id) (cdr (syntax-e stx)))])
(datum->syntax stx stx* stx))]))))