+;;;; 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
+;;;;
+\f
+;;; 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.
+\f
+
+(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