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<TITLE>LambdaMOO Programmer's Manual - Subsequences</TITLE>
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<H4><A NAME="SEC20" HREF="ProgrammersManual_toc.html#TOC20">Extracting a Subsequence of a List or String</A></H4>

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The range expression extracts a specified subsequence from a list or string:

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<PRE>
<VAR>expression-1</VAR>[<VAR>expression-2</VAR>..<VAR>expression-3</VAR>]
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<P>
The three expressions are evaluated in order.  <VAR>Expression-1</VAR> must return a
list or string (the <STRONG>sequence</STRONG>) and the other two expressions must return
integers (the <STRONG>low</STRONG> and <STRONG>high</STRONG> indices, respectively); otherwise,
<CODE>E_TYPE</CODE> is raised.  The <CODE>$</CODE> expression can be used in either or both
of <VAR>expression-2</VAR> and <VAR>expression-3</VAR> just as before, meaning the length
of the value of <VAR>expression-1</VAR>.

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<P>
If the low index is greater than the high index, then the empty string or list
is returned, depending on whether the sequence is a string or a list.
Otherwise, both indices must be between 1 and the length of the sequence;
<CODE>E_RANGE</CODE> is raised if they are not.  A new list or string is returned
that contains just the elements of the sequence with indices between the low
and high bounds.

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<PRE>
"foobar"[2..$]                       =>  "oobar"
"foobar"[3..3]                       =>  "o"
"foobar"[17..12]                     =>  ""
{"one", "two", "three"}[$ - 1..$]    =>  {"two", "three"}
{"one", "two", "three"}[3..3]        =>  {"three"}
{"one", "two", "three"}[17..12]      =>  {}
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