'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2001 Kevin B. Kenny <kennykb@acm.org>.  All rights reserved.
'\" Copyright (c) 2003-2004 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH lsearch n 8.6 Tcl "Tcl Built-In Commands"
.\" The -*- nroff -*- definitions below are for supplemental macros used
.\" in Tcl/Tk manual entries.
.\"
.\" .AP type name in/out ?indent?
.\"	Start paragraph describing an argument to a library procedure.
.\"	type is type of argument (int, etc.), in/out is either "in", "out",
.\"	or "in/out" to describe whether procedure reads or modifies arg,
.\"	and indent is equivalent to second arg of .IP (shouldn't ever be
.\"	needed;  use .AS below instead)
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.\"	name are examples of largest possible arguments that will be passed
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.\"
.\" .SO ?manpage?
.\"	Start of list of standard options for a Tk widget. The manpage
.\"	argument defines where to look up the standard options; if
.\"	omitted, defaults to "options". The options follow on successive
.\"	lines, in three columns separated by tabs.
.\"
.\" .SE
.\"	End of list of standard options for a Tk widget.
.\"
.\" .OP cmdName dbName dbClass
.\"	Start of description of a specific option.  cmdName gives the
.\"	option's name as specified in the class command, dbName gives
.\"	the option's name in the option database, and dbClass gives
.\"	the option's class in the option database.
.\"
.\" .UL arg1 arg2
.\"	Print arg1 underlined, then print arg2 normally.
.\"
.\" .QW arg1 ?arg2?
.\"	Print arg1 in quotes, then arg2 normally (for trailing punctuation).
.\"
.\" .PQ arg1 ?arg2?
.\"	Print an open parenthesis, arg1 in quotes, then arg2 normally
.\"	(for trailing punctuation) and then a closing parenthesis.
.\"
.\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
.\"	# Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
.el \{\
.   ie !"\\$2"" .TP \\n()Cu
.   el          .TP 15
.\}
.ta \\n()Au \\n()Bu
.ie !"\\$3"" \{\
\&\\$1 \\fI\\$2\\fP (\\$3)
.\".b
.\}
.el \{\
.br
.ie !"\\$2"" \{\
\&\\$1	\\fI\\$2\\fP
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.el \{\
\&\\fI\\$1\\fP
.\}
.\}
..
.\"	# define tabbing values for .AP
.de AS
.nr )A 10n
.if !"\\$1"" .nr )A \\w'\\$1'u+3n
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.\"
.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
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.\"	# ^b = 1
.de BS
.br
.mk ^y
.nr ^b 1u
.if n .nf
.if n .ti 0
.if n \l'\\n(.lu\(ul'
.if n .fi
..
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.de BE
.nf
.ti 0
.mk ^t
.ie n \l'\\n(^lu\(ul'
.el \{\
.\"	Draw four-sided box normally, but don't draw top of
.\"	box if the box started on an earlier page.
.ie !\\n(^b-1 \{\
\h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.el \}\
\h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.\}
.fi
.br
.nr ^b 0
..
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.\"	# ^v = 1 (for troff;  for nroff this doesn't matter)
.de VS
.if !"\\$2"" .br
.mk ^Y
.ie n 'mc \s12\(br\s0
.el .nr ^v 1u
..
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.de VE
.ie n 'mc
.el \{\
.ev 2
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\h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
.sp -1
.fi
.ev
.\}
.nr ^v 0
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.\"	# box/sidebar if in box/sidebar mode, then invoked standard
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.de ^B
.ev 2
'ti 0
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.\"	Draw three-sided box if this is the box's first page,
.\"	draw two sides but no top otherwise.
.ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.\}
.if \\n(^v \{\
.nr ^x \\n(^tu+1v-\\n(^Yu
\kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
.\}
.bp
'fi
.ev
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.mk ^Y
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..
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..
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.RE
.sp
..
.\"	# SO - start of list of standard options
.de SO
'ie '\\$1'' .ds So \\fBoptions\\fR
'el .ds So \\fB\\$1\\fR
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
.\"	# SE - end of list of standard options
.de SE
.fi
.ft R
.LP
See the \\*(So manual entry for details on the standard options.
..
.\"	# OP - start of full description for a single option
.de OP
.LP
.nf
.ta 4c
Command-Line Name:	\\fB\\$1\\fR
Database Name:	\\fB\\$2\\fR
Database Class:	\\fB\\$3\\fR
.fi
.IP
..
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.de UL
\\$1\l'|0\(ul'\\$2
..
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.de QW
.ie '\\*(lq'"' ``\\$1''\\$2
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\$2
..
.\"	# PQ - apply parens and quotation marks to word
.de PQ
.ie '\\*(lq'"' (``\\$1''\\$2)\\$3
.\"" fix emacs highlighting
.el (\\*(lq\\$1\\*(rq\\$2)\\$3
..
.\"	# QR - quoted range
.de QR
.ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
..
.\"	# MT - "empty" string
.de MT
.QW ""
..
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
lsearch \- See if a list contains a particular element
.SH SYNOPSIS
\fBlsearch \fR?\fIoptions\fR? \fIlist pattern\fR
.BE
.SH DESCRIPTION
.PP
This command searches the elements of \fIlist\fR to see if one
of them matches \fIpattern\fR.  If so, the command returns the index
of the first matching element
(unless the options \fB\-all\fR or \fB\-inline\fR are specified.)
If not, the command returns \fB\-1\fR or (if options \fB\-all\fR
or \fB\-inline\fR are specified) the empty string.  The \fIoption\fR arguments
indicates how the elements of the list are to be matched against
\fIpattern\fR and must have one of the values below:
.SS "MATCHING STYLE OPTIONS"
.PP
If all matching style options are omitted, the default matching style
is \fB\-glob\fR.  If more than one matching style is specified, the
last matching style given takes precedence.
.\" OPTION: -exact
.TP
\fB\-exact\fR
.
\fIPattern\fR is a literal string that is compared for exact equality
against each list element.
.\" OPTION: -glob
.TP
\fB\-glob\fR
.
\fIPattern\fR is a glob-style pattern which is matched against each list
element using the same rules as the \fBstring match\fR command.
.\" OPTION: -regexp
.TP
\fB\-regexp\fR
.
\fIPattern\fR is treated as a regular expression and matched against
each list element using the rules described in the \fBre_syntax\fR
reference page.
.\" OPTION: -sorted
.TP
\fB\-sorted\fR
.
The list elements are in sorted order.  If this option is specified,
\fBlsearch\fR will use a more efficient searching algorithm to search
\fIlist\fR.  If no other options are specified, \fIlist\fR is assumed
to be sorted in increasing order, and to contain ASCII strings.  This
option is mutually exclusive with \fB\-glob\fR and \fB\-regexp\fR, and
is treated exactly like \fB\-exact\fR when either \fB\-all\fR or
\fB\-not\fR are specified.
.SS "GENERAL MODIFIER OPTIONS"
.PP
These options may be given with all matching styles.
.\" OPTION: -all
.TP
\fB\-all\fR
.
Changes the result to be the list of all matching indices (or all matching
values if \fB\-inline\fR is specified as well.) If indices are returned, the
indices will be in ascending numeric order. If values are returned, the order
of the values will be the order of those values within the input \fIlist\fR.
.\" OPTION: -inline
.TP
\fB\-inline\fR
.
The matching value is returned instead of its index (or an empty
string if no value matches.)  If \fB\-all\fR is also specified, then
the result of the command is the list of all values that matched.
.\" OPTION: -not
.TP
\fB\-not\fR
.
This negates the sense of the match, returning the index of the first
non-matching value in the list.
.\" OPTION: -start
.TP
\fB\-start\fR\0\fIindex\fR
.
The list is searched starting at position \fIindex\fR.
The interpretation of the \fIindex\fR value is the same as
for the command \fBstring index\fR, supporting simple index
arithmetic and indices relative to the end of the list.
.SS "CONTENTS DESCRIPTION OPTIONS"
.PP
These options describe how to interpret the items in the list being
searched.  They are only meaningful when used with the \fB\-exact\fR
and \fB\-sorted\fR options.  If more than one is specified, the last
one takes precedence.  The default is \fB\-ascii\fR.
.\" OPTION: -ascii
.TP
\fB\-ascii\fR
.
The list elements are to be examined as Tcl strings (i.e. sequences of
Unicode code points; the name is for backward-compatibility reasons.)
.\" OPTION: -dictionary
.TP
\fB\-dictionary\fR
.
The list elements are to be compared using dictionary-style
comparisons (see \fBlsort\fR for a fuller description). Note that this
only makes a meaningful difference from the \fB\-ascii\fR option when
the \fB\-sorted\fR option is given, because values are only
dictionary-equal when exactly equal.
.\" OPTION: -integer
.TP
\fB\-integer\fR
.
The list elements are to be compared as integers.
.\" OPTION: -nocase
.TP
\fB\-nocase\fR
.
Causes comparisons to be handled in a case-insensitive manner.  Has no
effect if combined with the \fB\-dictionary\fR, \fB\-integer\fR, or
\fB\-real\fR options.
.\" OPTION: -real
.TP
\fB\-real\fR
.
The list elements are to be compared as floating-point values.
.SS "SORTED LIST OPTIONS"
.PP
These options (only meaningful with the \fB\-sorted\fR option) specify
how the list is sorted.  If more than one is given, the last one takes
precedence.  The default option is \fB\-increasing\fR.
.\" OPTION: -decreasing
.TP
\fB\-decreasing\fR
.
The list elements are sorted in decreasing order.  This option is only
meaningful when used with \fB\-sorted\fR.
.\" OPTION: -increasing
.TP
\fB\-increasing\fR
.
The list elements are sorted in increasing order.  This option is only
meaningful when used with \fB\-sorted\fR.
.\" OPTION: -bisect
.TP
\fB\-bisect\fR
.
Inexact search when the list elements are in sorted order. For an increasing
list the last index where the element is less than or equal to the pattern
is returned. For a decreasing list the last index where the element is greater
than or equal to the pattern is returned. If the pattern is before the first
element or the list is empty, -1 is returned.
This option implies \fB\-sorted\fR and cannot be used with either \fB\-all\fR
or \fB\-not\fR.
.SS "NESTED LIST OPTIONS"
.PP
These options are used to search lists of lists.  They may be used
with any other options.
.\" OPTION: -stride
.TP
\fB\-stride\0\fIstrideLength\fR
.
If this option is specified, the list is treated as consisting of
groups of \fIstrideLength\fR elements and the groups are searched by
either their first element or, if the \fB\-index\fR option is used,
by the element within each group given by the first index passed to
\fB\-index\fR (which is then ignored by \fB\-index\fR). The resulting
index always points to the first element in a group.
.PP
The list length must be an integer multiple of \fIstrideLength\fR, which
in turn must be at least 1. A \fIstrideLength\fR of 1 is the default and
indicates no grouping.
.\" OPTION: -index
.TP
\fB\-index\fR\0\fIindexList\fR
.
This option is designed for use when searching within nested lists.
The \fIindexList\fR argument gives a path of indices (much as might be
used with the \fBlindex\fR or \fBlset\fR commands) within each element
to allow the location of the term being matched against.
.\" OPTION: -subindices
.TP
\fB\-subindices\fR
.
If this option is given, the index result from this command (or every
index result when \fB\-all\fR is also specified) will be a complete
path (suitable for use with \fBlindex\fR or \fBlset\fR) within the
overall list to the term found.  This option has no effect unless the
\fB\-index\fR is also specified, and is just a convenience short-cut.
.SH EXAMPLES
.PP
Basic searching:
.PP
.CS
\fBlsearch\fR {a b c d e} c
      \fI\(-> 2\fR
\fBlsearch\fR -all {a b c a b c} c
      \fI\(-> 2 5\fR
.CE
.PP
Using \fBlsearch\fR to filter lists:
.PP
.CS
\fBlsearch\fR -inline {a20 b35 c47} b*
      \fI\(-> b35\fR
\fBlsearch\fR -inline -not {a20 b35 c47} b*
      \fI\(-> a20\fR
\fBlsearch\fR -all -inline -not {a20 b35 c47} b*
      \fI\(-> a20 c47\fR
\fBlsearch\fR -all -not {a20 b35 c47} b*
      \fI\(-> 0 2\fR
.CE
.PP
This can even do a
.QW set-like
removal operation:
.PP
.CS
\fBlsearch\fR -all -inline -not -exact {a b c a d e a f g a} a
      \fI\(-> b c d e f g\fR
.CE
.PP
Searching may start part-way through the list:
.PP
.CS
\fBlsearch\fR -start 3 {a b c a b c} c
      \fI\(-> 5\fR
.CE
.PP
It is also possible to search inside elements:
.PP
.CS
\fBlsearch\fR -index 1 -all -inline {{abc abc} {abc bcd} {abc cde}} *bc*
      \fI\(-> {abc abc} {abc bcd}\fR
.CE
.PP
The same thing for a flattened list:
.PP
.CS
\fBlsearch\fR -stride 2 -index 1 -all -inline {abc abc abc bcd abc cde} *bc*
      \fI\(-> abc abc abc bcd\fR
.CE
.SH "SEE ALSO"
foreach(n),
list(n), lappend(n), lassign(n), ledit(n), lindex(n), linsert(n), llength(n),
lmap(n), lpop(n), lrange(n), lremove(n), lrepeat(n), lreplace(n),
lreverse(n), lseq(n), lset(n), lsort(n),
string(n)
.SH KEYWORDS
binary search, linear search,
list, match, pattern, regular expression, search, string
'\" Local Variables:
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