File: expect.scm

package info (click to toggle)
guile-core 1%3A1.4-24
  • links: PTS
  • area: main
  • in suites: woody
  • size: 6,280 kB
  • ctags: 6,664
  • sloc: ansic: 49,704; lisp: 9,376; sh: 9,209; asm: 1,580; makefile: 696; awk: 198; csh: 50
file content (155 lines) | stat: -rw-r--r-- 5,043 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
;;;; 	Copyright (C) 1996, 1998, 1999 Free Software Foundation, Inc.
;;;; 
;;;; This program is free software; you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation; either version 2, or (at your option)
;;;; any later version.
;;;; 
;;;; This program 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 General Public License for more details.
;;;; 
;;;; You should have received a copy of the GNU General Public License
;;;; along with this software; see the file COPYING.  If not, write to
;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
;;;; Boston, MA 02111-1307 USA
;;;; 


(define-module (ice-9 expect) :use-module (ice-9 regex))

;;; 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-public expect-port #f)
(define-public expect-timeout #f)
(define-public expect-timeout-proc #f)
(define-public expect-eof-proc #f)
(define-public expect-char-proc #f)

;;; expect: each test is a procedure which is applied to the accumulating
;;; string.
(defmacro-public expect clauses
  (let ((s (gentemp))
	(c (gentemp))
	(port (gentemp))
	(timeout (gentemp)))
    `(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-public expect-strings-compile-flags regexp/newline)
(define-public expect-strings-exec-flags regexp/noteol)

;;; the regexec front-end to expect:
;;; each test must evaluate to a regular expression.
(defmacro-public 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 (gentemp)))
		     (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-public (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-public (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)))