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- # 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.
- #
- # See the file "license.terms" for information on usage and redistribution
- # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
- #
- # SCCS: @(#) word.tcl 1.2 96/11/20 14:07:22
- #
- # See the file "license.terms" for information on usage and redistribution
- # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
- #
-
- # The following variables are used to determine which characters are
- # interpreted as white space.
-
- if {$tcl_platform(platform) == "windows"} {
- # Windows style - any but space, tab, or newline
- set tcl_wordchars "\[^ \t\n\]"
- set tcl_nonwordchars "\[ \t\n\]"
- } else {
- # Motif style - any number, letter, or underscore
- set tcl_wordchars {[a-zA-Z0-9_]}
- set tcl_nonwordchars {[^a-zA-Z0-9_]}
- }
-
- # 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 {[string compare $start end] == 0} {
- 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 {[string compare $start end] == 0} {
- 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
- }
-