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;;;; r4rs.scm --- definitions needed for libguile to be R4RS compliant | |
;;;; Jim Blandy <jimb@cyclic.com> --- October 1996 | |
;;;; Copyright (C) 1996, 1997, 1998, 2000, 2001, 2006 Free Software Foundation, Inc. | |
;;;; | |
;;;; This library is free software; you can redistribute it and/or | |
;;;; modify it under the terms of the GNU Lesser General Public | |
;;;; License as published by the Free Software Foundation; either | |
;;;; version 2.1 of the License, or (at your option) any later version. | |
;;;; | |
;;;; This library is distributed in the hope that it will be useful, | |
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
;;;; Lesser General Public License for more details. | |
;;;; | |
;;;; You should have received a copy of the GNU Lesser General Public | |
;;;; License along with this library; if not, write to the Free Software | |
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
;;;; apply and call-with-current-continuation | |
;;; We want these to be tail-recursive, so instead of using primitive | |
;;; procedures, we define them as closures in terms of the primitive | |
;;; macros @apply and @call-with-current-continuation. | |
(set! apply (lambda (fun . args) (@apply fun (apply:nconc2last args)))) | |
(set-procedure-property! apply 'name 'apply) | |
(define (call-with-current-continuation proc) | |
(@call-with-current-continuation proc)) | |
(define (call-with-values producer consumer) | |
(@call-with-values producer consumer)) | |
;;;; Basic Port Code | |
;;; Specifically, the parts of the low-level port code that are written in | |
;;; Scheme rather than C. | |
;;; | |
;;; WARNING: the parts of this interface that refer to file ports | |
;;; are going away. It would be gone already except that it is used | |
;;; "internally" in a few places. | |
;;; OPEN_READ, OPEN_WRITE, and OPEN_BOTH are used to request the | |
;;; proper mode to open files in. | |
;;; | |
;;; If we want to support systems that do CRLF->LF translation, like | |
;;; Windows, then we should have a symbol in scmconfig.h made visible | |
;;; to the Scheme level that we can test here, and autoconf magic to | |
;;; #define it when appropriate. Windows will probably just have a | |
;;; hand-generated scmconfig.h file. | |
(define OPEN_READ "r") | |
(define OPEN_WRITE "w") | |
(define OPEN_BOTH "r+") | |
(define *null-device* "/dev/null") | |
(define (open-input-file str) | |
"Takes a string naming an existing file and returns an input port | |
capable of delivering characters from the file. If the file | |
cannot be opened, an error is signalled." | |
(open-file str OPEN_READ)) | |
(define (open-output-file str) | |
"Takes a string naming an output file to be created and returns an | |
output port capable of writing characters to a new file by that | |
name. If the file cannot be opened, an error is signalled. If a | |
file with the given name already exists, the effect is unspecified." | |
(open-file str OPEN_WRITE)) | |
(define (open-io-file str) | |
"Open file with name STR for both input and output." | |
(open-file str OPEN_BOTH)) | |
(define close-io-port close-port) | |
(define (call-with-input-file str proc) | |
"PROC should be a procedure of one argument, and STR should be a | |
string naming a file. The file must | |
already exist. These procedures call PROC | |
with one argument: the port obtained by opening the named file for | |
input or output. If the file cannot be opened, an error is | |
signalled. If the procedure returns, then the port is closed | |
automatically and the value yielded by the procedure is returned. | |
If the procedure does not return, then the port will not be closed | |
automatically unless it is possible to prove that the port will | |
never again be used for a read or write operation." | |
(let* ((file (open-input-file str)) | |
(ans (proc file))) | |
(close-input-port file) | |
ans)) | |
(define (call-with-output-file str proc) | |
"PROC should be a procedure of one argument, and STR should be a | |
string naming a file. The behaviour is unspecified if the file | |
already exists. These procedures call PROC | |
with one argument: the port obtained by opening the named file for | |
input or output. If the file cannot be opened, an error is | |
signalled. If the procedure returns, then the port is closed | |
automatically and the value yielded by the procedure is returned. | |
If the procedure does not return, then the port will not be closed | |
automatically unless it is possible to prove that the port will | |
never again be used for a read or write operation." | |
(let* ((file (open-output-file str)) | |
(ans (proc file))) | |
(close-output-port file) | |
ans)) | |
(define (with-input-from-port port thunk) | |
(let* ((swaports (lambda () (set! port (set-current-input-port port))))) | |
(dynamic-wind swaports thunk swaports))) | |
(define (with-output-to-port port thunk) | |
(let* ((swaports (lambda () (set! port (set-current-output-port port))))) | |
(dynamic-wind swaports thunk swaports))) | |
(define (with-error-to-port port thunk) | |
(let* ((swaports (lambda () (set! port (set-current-error-port port))))) | |
(dynamic-wind swaports thunk swaports))) | |
(define (with-input-from-file file thunk) | |
"THUNK must be a procedure of no arguments, and FILE must be a | |
string naming a file. The file must already exist. The file is opened for | |
input, an input port connected to it is made | |
the default value returned by `current-input-port', | |
and the THUNK is called with no arguments. | |
When the THUNK returns, the port is closed and the previous | |
default is restored. Returns the value yielded by THUNK. If an | |
escape procedure is used to escape from the continuation of these | |
procedures, their behavior is implementation dependent." | |
(let* ((nport (open-input-file file)) | |
(ans (with-input-from-port nport thunk))) | |
(close-port nport) | |
ans)) | |
(define (with-output-to-file file thunk) | |
"THUNK must be a procedure of no arguments, and FILE must be a | |
string naming a file. The effect is unspecified if the file already exists. | |
The file is opened for output, an output port connected to it is made | |
the default value returned by `current-output-port', | |
and the THUNK is called with no arguments. | |
When the THUNK returns, the port is closed and the previous | |
default is restored. Returns the value yielded by THUNK. If an | |
escape procedure is used to escape from the continuation of these | |
procedures, their behavior is implementation dependent." | |
(let* ((nport (open-output-file file)) | |
(ans (with-output-to-port nport thunk))) | |
(close-port nport) | |
ans)) | |
(define (with-error-to-file file thunk) | |
"THUNK must be a procedure of no arguments, and FILE must be a | |
string naming a file. The effect is unspecified if the file already exists. | |
The file is opened for output, an output port connected to it is made | |
the default value returned by `current-error-port', | |
and the THUNK is called with no arguments. | |
When the THUNK returns, the port is closed and the previous | |
default is restored. Returns the value yielded by THUNK. If an | |
escape procedure is used to escape from the continuation of these | |
procedures, their behavior is implementation dependent." | |
(let* ((nport (open-output-file file)) | |
(ans (with-error-to-port nport thunk))) | |
(close-port nport) | |
ans)) | |
(define (with-input-from-string string thunk) | |
"THUNK must be a procedure of no arguments. | |
The test of STRING is opened for | |
input, an input port connected to it is made, | |
and the THUNK is called with no arguments. | |
When the THUNK returns, the port is closed. | |
Returns the value yielded by THUNK. If an | |
escape procedure is used to escape from the continuation of these | |
procedures, their behavior is implementation dependent." | |
(call-with-input-string string | |
(lambda (p) (with-input-from-port p thunk)))) | |
(define (with-output-to-string thunk) | |
"Calls THUNK and returns its output as a string." | |
(call-with-output-string | |
(lambda (p) (with-output-to-port p thunk)))) | |
(define (with-error-to-string thunk) | |
"Calls THUNK and returns its error output as a string." | |
(call-with-output-string | |
(lambda (p) (with-error-to-port p thunk)))) | |
(define the-eof-object (call-with-input-string "" (lambda (p) (read-char p)))) | |
;;;; Loading | |
(if (not (defined? '%load-verbosely)) | |
(define %load-verbosely #f)) | |
(define (assert-load-verbosity v) (set! %load-verbosely v)) | |
(define (%load-announce file) | |
(if %load-verbosely | |
(with-output-to-port (current-error-port) | |
(lambda () | |
(display ";;; ") | |
(display "loading ") | |
(display file) | |
(newline) | |
(force-output))))) | |
(set! %load-hook %load-announce) | |
(define (load name . reader) | |
(with-fluid* current-reader (and (pair? reader) (car reader)) | |
(lambda () | |
(start-stack 'load-stack | |
(primitive-load name))))) | |