summaryrefslogtreecommitdiffstats
path: root/library/word.tcl
blob: c18c961538cdf89d1eefa46953ef9fdf2c0b41de (plain)
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
# word.tcl --
#
# This file defines various procedures for computing word boundaries
# in strings.  This file is primarily needed so Tk text and entry
# widgets behave properly for different platforms.
#
# Copyright (c) 1996 by Sun Microsystems, Inc.
# Copyright (c) 1998 by Scritpics Corporation.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# 
# RCS: @(#) $Id: word.tcl,v 1.7.2.1 2005/07/22 21:59:41 dgp Exp $

# The following variables are used to determine which characters are
# interpreted as white space.  

if {$::tcl_platform(platform) eq "windows"} {
    # Windows style - any but a unicode space char
    set tcl_wordchars "\\S"
    set tcl_nonwordchars "\\s"
} else {
    # Motif style - any unicode word char (number, letter, or underscore)
    set tcl_wordchars "\\w"
    set tcl_nonwordchars "\\W"
}

# tcl_wordBreakAfter --
#
# This procedure returns the index of the first word boundary
# after the starting point in the given string, or -1 if there
# are no more boundaries in the given string.  The index returned refers
# to the first character of the pair that comprises a boundary.
#
# Arguments:
# str -		String to search.
# start -	Index into string specifying starting point.

proc tcl_wordBreakAfter {str start} {
    global tcl_nonwordchars tcl_wordchars
    set str [string range $str $start end]
    if {[regexp -indices "$tcl_wordchars$tcl_nonwordchars|$tcl_nonwordchars$tcl_wordchars" $str result]} {
	return [expr {[lindex $result 1] + $start}]
    }
    return -1
}

# tcl_wordBreakBefore --
#
# This procedure returns the index of the first word boundary
# before the starting point in the given string, or -1 if there
# are no more boundaries in the given string.  The index returned
# refers to the second character of the pair that comprises a boundary.
#
# Arguments:
# str -		String to search.
# start -	Index into string specifying starting point.

proc tcl_wordBreakBefore {str start} {
    global tcl_nonwordchars tcl_wordchars
    if {$start eq "end"} {
	set start [string length $str]
    }
    if {[regexp -indices "^.*($tcl_wordchars$tcl_nonwordchars|$tcl_nonwordchars$tcl_wordchars)" [string range $str 0 $start] result]} {
	return [lindex $result 1]
    }
    return -1
}

# tcl_endOfWord --
#
# This procedure returns the index of the first end-of-word location
# after a starting index in the given string.  An end-of-word location
# is defined to be the first whitespace character following the first
# non-whitespace character after the starting point.  Returns -1 if
# there are no more words after the starting point.
#
# Arguments:
# str -		String to search.
# start -	Index into string specifying starting point.

proc tcl_endOfWord {str start} {
    global tcl_nonwordchars tcl_wordchars
    if {[regexp -indices "$tcl_nonwordchars*$tcl_wordchars+$tcl_nonwordchars" \
	    [string range $str $start end] result]} {
	return [expr {[lindex $result 1] + $start}]
    }
    return -1
}

# tcl_startOfNextWord --
#
# This procedure returns the index of the first start-of-word location
# after a starting index in the given string.  A start-of-word
# location is defined to be a non-whitespace character following a
# whitespace character.  Returns -1 if there are no more start-of-word
# locations after the starting point.
#
# Arguments:
# str -		String to search.
# start -	Index into string specifying starting point.

proc tcl_startOfNextWord {str start} {
    global tcl_nonwordchars tcl_wordchars
    if {[regexp -indices "$tcl_wordchars*$tcl_nonwordchars+$tcl_wordchars" \
	    [string range $str $start end] result]} {
	return [expr {[lindex $result 1] + $start}]
    }
    return -1
}

# tcl_startOfPreviousWord --
#
# This procedure returns the index of the first start-of-word location
# before a starting index in the given string.
#
# Arguments:
# str -		String to search.
# start -	Index into string specifying starting point.

proc tcl_startOfPreviousWord {str start} {
    global tcl_nonwordchars tcl_wordchars
    if {$start eq "end"} {
	set start [string length $str]
    }
    if {[regexp -indices \
	    "$tcl_nonwordchars*($tcl_wordchars+)$tcl_nonwordchars*\$" \
	    [string range $str 0 [expr {$start - 1}]] result word]} {
	return [lindex $word 0]
    }
    return -1
}