forked from lix-project/lix
Merge pull request #576 from qknight/args_explanation
extended args@ explanation
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5339ae4437
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@ -177,13 +177,19 @@ map (concat "foo") [ "bar" "bla" "abc" ]</programlisting>
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<listitem><para>An <literal>@</literal>-pattern provides a means of referring
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to the whole value being matched:
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<programlisting>
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args@{ x, y, z, ... }: z + y + x + args.a</programlisting>
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<programlisting> args@{ x, y, z, ... }: z + y + x + args.a</programlisting>
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but can also be written as:
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<programlisting> { x, y, z, ... } @ args: z + y + x + args.a</programlisting>
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Here <varname>args</varname> is bound to the entire argument, which
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is further matched against the pattern <literal>{ x, y, z,
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... }</literal>.</para></listitem>
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... }</literal>. <literal>@</literal>-pattern makes mainly sense with an
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ellipsis(<literal>...</literal>) as you can access attribute names as
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<literal>a</literal>, using <literal>args.a</literal>, which was given as an
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additional attribute to the function.
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</para></listitem>
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</itemizedlist>
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@ -359,4 +365,4 @@ character, or inline/multi-line, enclosed within <literal>/*
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</simplesect>
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</section>
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</section>
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