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# repeat.tcl --
#
# Emulation of string repeat for older
# revisions of Tcl.
#
# Copyright (c) 2000 by Ajuba Solutions.
# Copyright (c) 2001-2006 by Andreas Kupries <andreas_kupries@users.sourceforge.net>
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: repeat.tcl,v 1.1 2006/04/21 04:42:28 andreas_kupries Exp $
# ### ### ### ######### ######### #########
## Requirements
package require Tcl 8.5 9
namespace eval ::textutil::repeat {}
# ### ### ### ######### ######### #########
namespace eval ::textutil::repeat {
variable HaveBuiltin [expr {![catch {string repeat a 1}]}]
}
if {0} {
# Problems with the deactivated code:
# - Linear in 'num'.
# - Tests for 'string repeat' in every call!
# (Ok, just the variable, still a test every call)
# - Fails for 'num == 0' because of undefined 'str'.
proc textutil::repeat::StrRepeat { char num } {
variable HaveBuiltin
if { $HaveBuiltin == 0 } then {
for { set i 0 } { $i < $num } { incr i } {
append str $char
}
} else {
set str [ string repeat $char $num ]
}
return $str
}
}
if {$::textutil::repeat::HaveBuiltin} {
proc ::textutil::repeat::strRepeat {char num} {
return [string repeat $char $num]
}
proc ::textutil::repeat::blank {n} {
return [string repeat " " $n]
}
} else {
proc ::textutil::repeat::strRepeat {char num} {
if {$num <= 0} {
# No replication required
return ""
} elseif {$num == 1} {
# Quick exit for recursion
return $char
} elseif {$num == 2} {
# Another quick exit for recursion
return $char$char
} elseif {0 == ($num % 2)} {
# Halving the problem results in O (log n) complexity.
set result [strRepeat $char [expr {$num / 2}]]
return "$result$result"
} else {
# Uneven length, reduce problem by one
return "$char[strRepeat $char [incr num -1]]"
}
}
proc ::textutil::repeat::blank {n} {
return [strRepeat " " $n]
}
}
# ### ### ### ######### ######### #########
## Data structures
namespace eval ::textutil::repeat {
namespace export strRepeat blank
}
# ### ### ### ######### ######### #########
## Ready
package provide textutil::repeat 0.8
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