racket/collects/mzlib/include.ss
2005-05-27 18:56:37 +00:00

151 lines
4.1 KiB
Scheme

(module include mzscheme
(require-for-syntax (lib "stx.ss" "syntax")
(lib "path-spec.ss" "syntax")
"private/increader.ss"
"cm-accomplice.ss")
(require (lib "etc.ss"))
(define-syntax-set (do-include ; private
include-at/relative-to
include
include-at/relative-to/reader
include/reader)
(define (do-include/proc stx)
(syntax-case stx ()
[(_ orig-stx ctx loc fn reader)
;; Parse the file name
(let ([c-file (resolve-path-spec (syntax fn) (syntax loc) (syntax orig-stx) #'build-path)]
[ctx (syntax ctx)]
[loc (syntax loc)]
[reader (syntax reader)]
[orig-stx (syntax orig-stx)])
(register-external-file c-file)
(let ([read-syntax (if (syntax-e reader)
(reader-val
(let loop ([e (syntax-object->datum
(local-expand reader 'expression null))])
(cond
[(reader? e) e]
[(pair? e) (or (loop (car e))
(loop (cdr e)))]
[else #f])))
read-syntax)])
(unless (and (procedure? read-syntax)
(procedure-arity-includes? read-syntax 2))
(raise-syntax-error
#f
"reader is not a procedure of two arguments"
orig-stx))
;; Open the included file
(let ([p (with-handlers ([exn:fail?
(lambda (exn)
(raise-syntax-error
#f
(format
"can't open include file (~a)"
(if (exn? exn)
(exn-message exn)
exn))
orig-stx
c-file))])
(open-input-file c-file))])
(port-count-lines! p)
;; Read expressions from file
(let ([content
(let loop ()
(let ([r (with-handlers ([exn:fail?
(lambda (exn)
(close-input-port p)
(raise-syntax-error
#f
(format
"read error (~a)"
(if (exn? exn)
(exn-message exn)
exn))
orig-stx))])
(read-syntax c-file p))])
(if (eof-object? r)
null
(cons r (loop)))))])
(close-input-port p)
;; Preserve src info for content, but set its
;; lexical context to be that of the include expression
(let ([lexed-content
(let loop ([content content])
(cond
[(pair? content)
(cons (loop (car content))
(loop (cdr content)))]
[(null? content) null]
[else
(let ([v (syntax-e content)])
(datum->syntax-object
ctx
(cond
[(pair? v)
(loop v)]
[(vector? v)
(list->vector (loop (vector->list v)))]
[(box? v)
(box (loop (unbox v)))]
[else
v])
content))]))])
(datum->syntax-object
(quote-syntax here)
`(begin ,@lexed-content)
orig-stx))))))]))
(define (include/proc stx)
(syntax-case stx ()
[(_ fn)
(with-syntax ([_stx stx])
(syntax/loc stx (do-include _stx _stx _stx fn #f)))]))
(define (include-at/relative-to/proc stx)
(syntax-case stx ()
[(_ ctx loc fn)
(with-syntax ([_stx stx])
(syntax/loc stx (do-include _stx ctx loc fn #f)))]))
(define (include/reader/proc stx)
(syntax-case stx ()
[(_ fn reader)
;; Expand to do-include:
(with-syntax ([_stx stx])
(syntax/loc stx
(do-include _stx _stx _stx fn
(letrec-syntax ([the-reader (lambda (stx)
(datum->syntax-object
#'here
(make-reader reader)))])
the-reader))))]))
(define (include-at/relative-to/reader/proc stx)
(syntax-case stx ()
[(_ ctx loc fn reader)
(with-syntax ([_stx stx])
(syntax/loc stx
(do-include _stx ctx loc fn
(letrec-syntax ([the-reader (lambda (stx)
(datum->syntax-object
#'here
(make-reader reader)))])
the-reader))))])))
(provide include
include-at/relative-to
include/reader
include-at/relative-to/reader))