[Tcl-bugs] [ tcl-Bugs-1764318 ] Improve performance of tcl_startOfNextWord and friends...

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Bugs item #1764318, was opened at 2007-07-31 14:09
Message generated for change (Settings changed) made by petasis
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Category: 69. Other
Group: development: 8.4.16
Status: Open
Resolution: None
>Priority: 3
Private: No
Submitted By: Georgios Petasis (petasis)
Assigned to: Nobody/Anonymous (nobody)
>Summary: Improve performance of tcl_startOfNextWord and friends...

Initial Comment:
Hi all,

I have recently noticed that the file word.tcl in the tcl library has not been updated to use the (relatively) new -start option of regexp. Changing the file word.tcl to remove [string range ...] call and use the -start regexp option, all the procs were made much faster, especially for large strings. 
As an example, the body of tcl_startOfNextWord:

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
}

Can be changed to:

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

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=110894&aid=1764318&group_id=10894