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;;;; Copyright (C) 1996, 1998, 1999, 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
;;;;
;;; Commentary:
;; This module is documented in the Guile Reference Manual.
;; Briefly, these are exported:
;; procedures: expect-select, expect-regexec
;; variables: expect-port, expect-timeout, expect-timeout-proc,
;; expect-eof-proc, expect-char-proc,
;; expect-strings-compile-flags, expect-strings-exec-flags,
;; macros: expect, expect-strings
;;; Code:
(define-module (ice-9 expect)
:use-module (ice-9 regex)
:export-syntax (expect expect-strings)
:export (expect-port expect-timeout expect-timeout-proc
expect-eof-proc expect-char-proc expect-strings-compile-flags
expect-strings-exec-flags expect-select expect-regexec))
;;; Expect: a macro for selecting actions based on what it reads from a port.
;;; The idea is from Don Libes' expect based on Tcl.
;;; This version by Gary Houston incorporating ideas from Aubrey Jaffer.
(define expect-port #f)
(define expect-timeout #f)
(define expect-timeout-proc #f)
(define expect-eof-proc #f)
(define expect-char-proc #f)
;;; expect: each test is a procedure which is applied to the accumulating
;;; string.
(defmacro expect clauses
(let ((s (gensym))
(c (gensym))
(port (gensym))
(timeout (gensym)))
`(let ((,s "")
(,port (or expect-port (current-input-port)))
;; when timeout occurs, in floating point seconds.
(,timeout (if expect-timeout
(let* ((secs-usecs (gettimeofday)))
(+ (car secs-usecs)
expect-timeout
(/ (cdr secs-usecs)
1000000))) ; one million.
#f)))
(let next-char ()
(if (and expect-timeout
(not (expect-select ,port ,timeout)))
(if expect-timeout-proc
(expect-timeout-proc ,s)
#f)
(let ((,c (read-char ,port)))
(if expect-char-proc
(expect-char-proc ,c))
(if (not (eof-object? ,c))
(set! ,s (string-append ,s (string ,c))))
(cond
;; this expands to clauses where the car invokes the
;; match proc and the cdr is the return value from expect
;; if the proc matched.
,@(let next-expr ((tests (map car clauses))
(exprs (map cdr clauses))
(body '()))
(cond
((null? tests)
(reverse body))
(else
(next-expr
(cdr tests)
(cdr exprs)
(cons
`((,(car tests) ,s (eof-object? ,c))
,@(cond ((null? (car exprs))
'())
((eq? (caar exprs) '=>)
(if (not (= (length (car exprs))
2))
(scm-error 'misc-error
"expect"
"bad recipient: ~S"
(list (car exprs))
#f)
`((apply ,(cadar exprs)
(,(car tests) ,s ,port)))))
(else
(car exprs))))
body)))))
;; if none of the clauses matched the current string.
(else (cond ((eof-object? ,c)
(if expect-eof-proc
(expect-eof-proc ,s)
#f))
(else
(next-char)))))))))))
(define expect-strings-compile-flags regexp/newline)
(define expect-strings-exec-flags regexp/noteol)
;;; the regexec front-end to expect:
;;; each test must evaluate to a regular expression.
(defmacro expect-strings clauses
`(let ,@(let next-test ((tests (map car clauses))
(exprs (map cdr clauses))
(defs '())
(body '()))
(cond ((null? tests)
(list (reverse defs) `(expect ,@(reverse body))))
(else
(let ((rxname (gensym)))
(next-test (cdr tests)
(cdr exprs)
(cons `(,rxname (make-regexp
,(car tests)
expect-strings-compile-flags))
defs)
(cons `((lambda (s eof?)
(expect-regexec ,rxname s eof?))
,@(car exprs))
body))))))))
;;; simplified select: returns #t if input is waiting or #f if timed out or
;;; select was interrupted by a signal.
;;; timeout is an absolute time in floating point seconds.
(define (expect-select port timeout)
(let* ((secs-usecs (gettimeofday))
(relative (- timeout
(car secs-usecs)
(/ (cdr secs-usecs)
1000000)))) ; one million.
(and (> relative 0)
(pair? (car (select (list port) '() '()
relative))))))
;;; match a string against a regexp, returning a list of strings (required
;;; by the => syntax) or #f. called once each time a character is added
;;; to s (eof? will be #f), and once when eof is reached (with eof? #t).
(define (expect-regexec rx s eof?)
;; if expect-strings-exec-flags contains regexp/noteol,
;; remove it for the eof test.
(let* ((flags (if (and eof?
(logand expect-strings-exec-flags regexp/noteol))
(logxor expect-strings-exec-flags regexp/noteol)
expect-strings-exec-flags))
(match (regexp-exec rx s 0 flags)))
(if match
(do ((i (- (match:count match) 1) (- i 1))
(result '() (cons (match:substring match i) result)))
((< i 0) result))
#f)))
;;; expect.scm ends here
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