1 | '\" |
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2 | '\" Copyright (c) 1993 The Regents of the University of California. |
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3 | '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. |
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4 | '\" Copyright (c) 2001 Kevin B. Kenny <kennykb@acm.org>. All rights reserved. |
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5 | '\" |
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6 | '\" See the file "license.terms" for information on usage and redistribution |
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7 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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8 | '\" |
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9 | '\" RCS: @(#) $Id: lrange.n,v 1.17 2008/03/26 09:59:22 dkf Exp $ |
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10 | '\" |
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11 | .so man.macros |
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12 | .TH lrange n 7.4 Tcl "Tcl Built-In Commands" |
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13 | .BS |
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14 | '\" Note: do not modify the .SH NAME line immediately below! |
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15 | .SH NAME |
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16 | lrange \- Return one or more adjacent elements from a list |
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17 | .SH SYNOPSIS |
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18 | \fBlrange \fIlist first last\fR |
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19 | .BE |
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20 | |
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21 | .SH DESCRIPTION |
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22 | .PP |
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23 | \fIList\fR must be a valid Tcl list. This command will |
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24 | return a new list consisting of elements |
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25 | \fIfirst\fR through \fIlast\fR, inclusive. |
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26 | .VS 8.5 |
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27 | The index values \fIfirst\fR and \fIlast\fR are interpreted |
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28 | the same as index values for the command \fBstring index\fR, |
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29 | supporting simple index arithmetic and indices relative to the |
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30 | end of the list. |
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31 | .VE |
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32 | If \fIfirst\fR is less than zero, it is treated as if it were zero. |
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33 | If \fIlast\fR is greater than or equal to the number of elements |
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34 | in the list, then it is treated as if it were \fBend\fR. |
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35 | If \fIfirst\fR is greater than \fIlast\fR then an empty string |
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36 | is returned. |
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37 | Note: |
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38 | .QW "\fBlrange \fIlist first first\fR" |
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39 | does not always produce the same result as |
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40 | .QW "\fBlindex \fIlist first\fR" |
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41 | (although it often does for simple fields that are not enclosed in |
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42 | braces); it does, however, produce exactly the same results as |
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43 | .QW "\fBlist [lindex \fIlist first\fB]\fR" |
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44 | .SH EXAMPLES |
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45 | Selecting the first two elements: |
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46 | .CS |
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47 | % \fBlrange\fR {a b c d e} 0 1 |
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48 | a b |
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49 | .CE |
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50 | .PP |
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51 | Selecting the last three elements: |
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52 | .CS |
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53 | % \fBlrange\fR {a b c d e} end-2 end |
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54 | c d e |
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55 | .CE |
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56 | .PP |
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57 | Selecting everything except the first and last element: |
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58 | .CS |
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59 | % \fBlrange\fR {a b c d e} 1 end-1 |
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60 | b c d |
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61 | .CE |
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62 | .PP |
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63 | Selecting a single element with \fBlrange\fR is not the same as doing |
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64 | so with \fBlindex\fR: |
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65 | .CS |
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66 | % set var {some {elements to} select} |
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67 | some {elements to} select |
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68 | % lindex $var 1 |
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69 | elements to |
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70 | % \fBlrange\fR $var 1 1 |
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71 | {elements to} |
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72 | .CE |
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73 | |
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74 | .SH "SEE ALSO" |
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75 | list(n), lappend(n), lindex(n), linsert(n), llength(n), lsearch(n), |
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76 | lset(n), lreplace(n), lsort(n), |
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77 | .VS 8.5 |
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78 | string(n) |
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79 | .VE |
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80 | |
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81 | .SH KEYWORDS |
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82 | element, list, range, sublist |
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