File: C:/Ruby27-x64/share/doc/ruby/html/OptionParser/Switch.html
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<h3>Parent</h3>
<p class="link"><a href="../Object.html">Object</a>
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<!-- Method Quickref -->
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<h3>Methods</h3>
<ul class="link-list" role="directory">
<li ><a href="#method-c-guess">::guess</a>
<li ><a href="#method-c-incompatible_argument_styles">::incompatible_argument_styles</a>
<li ><a href="#method-c-new">::new</a>
<li ><a href="#method-c-pattern">::pattern</a>
<li ><a href="#method-i-conv_arg">#conv_arg</a>
<li ><a href="#method-i-parse_arg">#parse_arg</a>
<li ><a href="#method-i-summarize">#summarize</a>
<li ><a href="#method-i-switch_name">#switch_name</a>
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<main role="main" aria-labelledby="class-OptionParser::Switch">
<h1 id="class-OptionParser::Switch" class="class">
class OptionParser::Switch
</h1>
<section class="description">
<p>Individual switch class. Not important to the user.</p>
<p>Defined within <a href="Switch.html"><code>Switch</code></a> are several Switch-derived classes: <a href="Switch/NoArgument.html"><code>NoArgument</code></a>, <a href="Switch/RequiredArgument.html"><code>RequiredArgument</code></a>, etc.</p>
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section class="attribute-method-details" class="method-section">
<header>
<h3>Attributes</h3>
</header>
<div id="attribute-i-arg" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">arg</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-block" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">block</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-conv" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">conv</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-desc" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">desc</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-long" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">long</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-pattern" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">pattern</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
<div id="attribute-i-short" class="method-detail">
<div class="method-heading attribute-method-heading">
<span class="method-name">short</span><span
class="attribute-access-type">[R]</span>
</div>
<div class="method-description">
</div>
</div>
</section>
<section id="public-class-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Class Methods</h3>
</header>
<div id="method-c-guess" class="method-detail ">
<div class="method-heading">
<span class="method-name">guess</span><span
class="method-args">(arg)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Guesses argument style from <code>arg</code>. Returns corresponding <a href="Switch.html"><code>OptionParser::Switch</code></a> class (<a href="Switch/OptionalArgument.html"><code>OptionalArgument</code></a>, etc.).</p>
<div class="method-source-code" id="guess-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 511</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">guess</span>(<span class="ruby-identifier">arg</span>)
<span class="ruby-keyword">case</span> <span class="ruby-identifier">arg</span>
<span class="ruby-keyword">when</span> <span class="ruby-string">""</span>
<span class="ruby-identifier">t</span> = <span class="ruby-keyword">self</span>
<span class="ruby-keyword">when</span> <span class="ruby-regexp">/\A=?\[/</span>
<span class="ruby-identifier">t</span> = <span class="ruby-constant">Switch</span><span class="ruby-operator">::</span><span class="ruby-constant">OptionalArgument</span>
<span class="ruby-keyword">when</span> <span class="ruby-regexp">/\A\s+\[/</span>
<span class="ruby-identifier">t</span> = <span class="ruby-constant">Switch</span><span class="ruby-operator">::</span><span class="ruby-constant">PlacedArgument</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">t</span> = <span class="ruby-constant">Switch</span><span class="ruby-operator">::</span><span class="ruby-constant">RequiredArgument</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">self</span> <span class="ruby-operator">>=</span> <span class="ruby-identifier">t</span> <span class="ruby-keyword">or</span> <span class="ruby-identifier">incompatible_argument_styles</span>(<span class="ruby-identifier">arg</span>, <span class="ruby-identifier">t</span>)
<span class="ruby-identifier">t</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-incompatible_argument_styles" class="method-detail ">
<div class="method-heading">
<span class="method-name">incompatible_argument_styles</span><span
class="method-args">(arg, t)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<div class="method-source-code" id="incompatible_argument_styles-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 526</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">incompatible_argument_styles</span>(<span class="ruby-identifier">arg</span>, <span class="ruby-identifier">t</span>)
<span class="ruby-identifier">raise</span>(<span class="ruby-constant">ArgumentError</span>, <span class="ruby-node">"#{arg}: incompatible argument styles\n #{self}, #{t}"</span>,
<span class="ruby-constant">ParseError</span>.<span class="ruby-identifier">filter_backtrace</span>(<span class="ruby-identifier">caller</span>(<span class="ruby-value">2</span>)))
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-new" class="method-detail ">
<div class="method-heading">
<span class="method-name">new</span><span
class="method-args">(pattern = nil, conv = nil, short = nil, long = nil, arg = nil, desc = ([] if short or long), block = nil, &_block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<div class="method-source-code" id="new-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 535</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">initialize</span>(<span class="ruby-identifier">pattern</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-identifier">conv</span> = <span class="ruby-keyword">nil</span>,
<span class="ruby-identifier">short</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-identifier">long</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-identifier">arg</span> = <span class="ruby-keyword">nil</span>,
<span class="ruby-identifier">desc</span> = ([] <span class="ruby-keyword">if</span> <span class="ruby-identifier">short</span> <span class="ruby-keyword">or</span> <span class="ruby-identifier">long</span>), <span class="ruby-identifier">block</span> = <span class="ruby-keyword">nil</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">_block</span>)
<span class="ruby-identifier">raise</span> <span class="ruby-keyword">if</span> <span class="ruby-constant">Array</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">pattern</span>
<span class="ruby-identifier">block</span> <span class="ruby-operator">||=</span> <span class="ruby-identifier">_block</span>
<span class="ruby-ivar">@pattern</span>, <span class="ruby-ivar">@conv</span>, <span class="ruby-ivar">@short</span>, <span class="ruby-ivar">@long</span>, <span class="ruby-ivar">@arg</span>, <span class="ruby-ivar">@desc</span>, <span class="ruby-ivar">@block</span> =
<span class="ruby-identifier">pattern</span>, <span class="ruby-identifier">conv</span>, <span class="ruby-identifier">short</span>, <span class="ruby-identifier">long</span>, <span class="ruby-identifier">arg</span>, <span class="ruby-identifier">desc</span>, <span class="ruby-identifier">block</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pattern" class="method-detail ">
<div class="method-heading">
<span class="method-name">pattern</span><span
class="method-args">()</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<div class="method-source-code" id="pattern-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 531</span>
<span class="ruby-keyword">def</span> <span class="ruby-keyword">self</span>.<span class="ruby-identifier ruby-title">pattern</span>
<span class="ruby-constant">NilClass</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
</section>
<section id="public-instance-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Instance Methods</h3>
</header>
<div id="method-i-summarize" class="method-detail ">
<div class="method-heading">
<span class="method-name">summarize</span><span
class="method-args">(sdone = {}, ldone = {}, width = 1, max = width - 1, indent = "") { |indent| ... }</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Produces the summary text. Each line of the summary is yielded to the block (without newline).</p>
<dl class="rdoc-list note-list"><dt><code>sdone</code>
<dd>
<p>Already summarized short style options keyed hash.</p>
</dd><dt><code>ldone</code>
<dd>
<p>Already summarized long style options keyed hash.</p>
</dd><dt><code>width</code>
<dd>
<p>Width of left side (option part). In other words, the right side (description part) starts after <code>width</code> columns.</p>
</dd><dt><code>max</code>
<dd>
<p>Maximum width of left side -> the options are filled within <code>max</code> columns.</p>
</dd><dt><code>indent</code>
<dd>
<p>Prefix string indents all summarized lines.</p>
</dd></dl>
<div class="method-source-code" id="summarize-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 595</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">summarize</span>(<span class="ruby-identifier">sdone</span> = {}, <span class="ruby-identifier">ldone</span> = {}, <span class="ruby-identifier">width</span> = <span class="ruby-value">1</span>, <span class="ruby-identifier">max</span> = <span class="ruby-identifier">width</span> <span class="ruby-operator">-</span> <span class="ruby-value">1</span>, <span class="ruby-identifier">indent</span> = <span class="ruby-string">""</span>)
<span class="ruby-identifier">sopts</span>, <span class="ruby-identifier">lopts</span> = [], [], <span class="ruby-keyword">nil</span>
<span class="ruby-ivar">@short</span>.<span class="ruby-identifier">each</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">s</span><span class="ruby-operator">|</span> <span class="ruby-identifier">sdone</span>.<span class="ruby-identifier">fetch</span>(<span class="ruby-identifier">s</span>) {<span class="ruby-identifier">sopts</span> <span class="ruby-operator"><<</span> <span class="ruby-identifier">s</span>}; <span class="ruby-identifier">sdone</span>[<span class="ruby-identifier">s</span>] = <span class="ruby-keyword">true</span>} <span class="ruby-keyword">if</span> <span class="ruby-ivar">@short</span>
<span class="ruby-ivar">@long</span>.<span class="ruby-identifier">each</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">s</span><span class="ruby-operator">|</span> <span class="ruby-identifier">ldone</span>.<span class="ruby-identifier">fetch</span>(<span class="ruby-identifier">s</span>) {<span class="ruby-identifier">lopts</span> <span class="ruby-operator"><<</span> <span class="ruby-identifier">s</span>}; <span class="ruby-identifier">ldone</span>[<span class="ruby-identifier">s</span>] = <span class="ruby-keyword">true</span>} <span class="ruby-keyword">if</span> <span class="ruby-ivar">@long</span>
<span class="ruby-keyword">return</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">sopts</span>.<span class="ruby-identifier">empty?</span> <span class="ruby-keyword">and</span> <span class="ruby-identifier">lopts</span>.<span class="ruby-identifier">empty?</span> <span class="ruby-comment"># completely hidden</span>
<span class="ruby-identifier">left</span> = [<span class="ruby-identifier">sopts</span>.<span class="ruby-identifier">join</span>(<span class="ruby-string">', '</span>)]
<span class="ruby-identifier">right</span> = <span class="ruby-identifier">desc</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">while</span> <span class="ruby-identifier">s</span> = <span class="ruby-identifier">lopts</span>.<span class="ruby-identifier">shift</span>
<span class="ruby-identifier">l</span> = <span class="ruby-identifier">left</span>[<span class="ruby-value">-1</span>].<span class="ruby-identifier">length</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">length</span>
<span class="ruby-identifier">l</span> <span class="ruby-operator">+=</span> <span class="ruby-identifier">arg</span>.<span class="ruby-identifier">length</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">left</span>.<span class="ruby-identifier">size</span> <span class="ruby-operator">==</span> <span class="ruby-value">1</span> <span class="ruby-operator">&&</span> <span class="ruby-identifier">arg</span>
<span class="ruby-identifier">l</span> <span class="ruby-operator"><</span> <span class="ruby-identifier">max</span> <span class="ruby-keyword">or</span> <span class="ruby-identifier">sopts</span>.<span class="ruby-identifier">empty?</span> <span class="ruby-keyword">or</span> <span class="ruby-identifier">left</span> <span class="ruby-operator"><<</span> <span class="ruby-string">+''</span>
<span class="ruby-identifier">left</span>[<span class="ruby-value">-1</span>] <span class="ruby-operator"><<</span> (<span class="ruby-identifier">left</span>[<span class="ruby-value">-1</span>].<span class="ruby-identifier">empty?</span> <span class="ruby-operator">?</span> <span class="ruby-string">' '</span> <span class="ruby-operator">*</span> <span class="ruby-value">4</span> <span class="ruby-operator">:</span> <span class="ruby-string">', '</span>) <span class="ruby-operator"><<</span> <span class="ruby-identifier">s</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">arg</span>
<span class="ruby-identifier">left</span>[<span class="ruby-value">0</span>] <span class="ruby-operator"><<</span> (<span class="ruby-identifier">left</span>[<span class="ruby-value">1</span>] <span class="ruby-operator">?</span> <span class="ruby-identifier">arg</span>.<span class="ruby-identifier">sub</span>(<span class="ruby-regexp">/\A(\[?)=/</span>, <span class="ruby-string">'\1'</span>) <span class="ruby-operator">+</span> <span class="ruby-string">','</span> <span class="ruby-operator">:</span> <span class="ruby-identifier">arg</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">mlen</span> = <span class="ruby-identifier">left</span>.<span class="ruby-identifier">collect</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">ss</span><span class="ruby-operator">|</span> <span class="ruby-identifier">ss</span>.<span class="ruby-identifier">length</span>}.<span class="ruby-identifier">max</span>.<span class="ruby-identifier">to_i</span>
<span class="ruby-keyword">while</span> <span class="ruby-identifier">mlen</span> <span class="ruby-operator">></span> <span class="ruby-identifier">width</span> <span class="ruby-keyword">and</span> <span class="ruby-identifier">l</span> = <span class="ruby-identifier">left</span>.<span class="ruby-identifier">shift</span>
<span class="ruby-identifier">mlen</span> = <span class="ruby-identifier">left</span>.<span class="ruby-identifier">collect</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">ss</span><span class="ruby-operator">|</span> <span class="ruby-identifier">ss</span>.<span class="ruby-identifier">length</span>}.<span class="ruby-identifier">max</span>.<span class="ruby-identifier">to_i</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">l</span>.<span class="ruby-identifier">length</span> <span class="ruby-operator">==</span> <span class="ruby-identifier">mlen</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">l</span>.<span class="ruby-identifier">length</span> <span class="ruby-operator"><</span> <span class="ruby-identifier">width</span> <span class="ruby-keyword">and</span> (<span class="ruby-identifier">r</span> = <span class="ruby-identifier">right</span>[<span class="ruby-value">0</span>]) <span class="ruby-keyword">and</span> <span class="ruby-operator">!</span><span class="ruby-identifier">r</span>.<span class="ruby-identifier">empty?</span>
<span class="ruby-identifier">l</span> = <span class="ruby-identifier">l</span>.<span class="ruby-identifier">to_s</span>.<span class="ruby-identifier">ljust</span>(<span class="ruby-identifier">width</span>) <span class="ruby-operator">+</span> <span class="ruby-string">' '</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">r</span>
<span class="ruby-identifier">right</span>.<span class="ruby-identifier">shift</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">yield</span>(<span class="ruby-identifier">indent</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">l</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">while</span> <span class="ruby-keyword">begin</span> <span class="ruby-identifier">l</span> = <span class="ruby-identifier">left</span>.<span class="ruby-identifier">shift</span>; <span class="ruby-identifier">r</span> = <span class="ruby-identifier">right</span>.<span class="ruby-identifier">shift</span>; <span class="ruby-identifier">l</span> <span class="ruby-keyword">or</span> <span class="ruby-identifier">r</span> <span class="ruby-keyword">end</span>
<span class="ruby-identifier">l</span> = <span class="ruby-identifier">l</span>.<span class="ruby-identifier">to_s</span>.<span class="ruby-identifier">ljust</span>(<span class="ruby-identifier">width</span>) <span class="ruby-operator">+</span> <span class="ruby-string">' '</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">r</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">r</span> <span class="ruby-keyword">and</span> <span class="ruby-operator">!</span><span class="ruby-identifier">r</span>.<span class="ruby-identifier">empty?</span>
<span class="ruby-keyword">yield</span>(<span class="ruby-identifier">indent</span> <span class="ruby-operator">+</span> <span class="ruby-identifier">l</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">self</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-switch_name" class="method-detail ">
<div class="method-heading">
<span class="method-name">switch_name</span><span
class="method-args">()</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Main name of the switch.</p>
<div class="method-source-code" id="switch_name-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 647</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">switch_name</span>
(<span class="ruby-identifier">long</span>.<span class="ruby-identifier">first</span> <span class="ruby-operator">||</span> <span class="ruby-identifier">short</span>.<span class="ruby-identifier">first</span>).<span class="ruby-identifier">sub</span>(<span class="ruby-regexp">/\A-+(?:\[no-\])?/</span>, <span class="ruby-string">''</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
</section>
<section id="private-instance-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Private Instance Methods</h3>
</header>
<div id="method-i-conv_arg" class="method-detail ">
<div class="method-heading">
<span class="method-name">conv_arg</span><span
class="method-args">(arg, val = [])</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Parses argument, converts and returns <code>arg</code>, <code>block</code> and result of conversion. Yields at semi-error condition instead of raising an exception.</p>
<div class="method-source-code" id="conv_arg-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 573</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">conv_arg</span>(<span class="ruby-identifier">arg</span>, <span class="ruby-identifier">val</span> = [])
<span class="ruby-keyword">if</span> <span class="ruby-identifier">conv</span>
<span class="ruby-identifier">val</span> = <span class="ruby-identifier">conv</span>.<span class="ruby-identifier">call</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">val</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">val</span> = <span class="ruby-identifier">proc</span> {<span class="ruby-operator">|</span><span class="ruby-identifier">v</span><span class="ruby-operator">|</span> <span class="ruby-identifier">v</span>}.<span class="ruby-identifier">call</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">val</span>)
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">return</span> <span class="ruby-identifier">arg</span>, <span class="ruby-identifier">block</span>, <span class="ruby-identifier">val</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-parse_arg" class="method-detail ">
<div class="method-heading">
<span class="method-name">parse_arg</span><span
class="method-args">(arg) { |InvalidArgument, arg| ... }</span>
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<div class="method-description">
<p>Parses <code>arg</code> and returns rest of <code>arg</code> and matched portion to the argument pattern. Yields when the pattern doesn't match substring.</p>
<div class="method-source-code" id="parse_arg-source">
<pre><span class="ruby-comment"># File lib/optparse.rb, line 548</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">parse_arg</span>(<span class="ruby-identifier">arg</span>)
<span class="ruby-identifier">pattern</span> <span class="ruby-keyword">or</span> <span class="ruby-keyword">return</span> <span class="ruby-keyword">nil</span>, [<span class="ruby-identifier">arg</span>]
<span class="ruby-keyword">unless</span> <span class="ruby-identifier">m</span> = <span class="ruby-identifier">pattern</span>.<span class="ruby-identifier">match</span>(<span class="ruby-identifier">arg</span>)
<span class="ruby-keyword">yield</span>(<span class="ruby-constant">InvalidArgument</span>, <span class="ruby-identifier">arg</span>)
<span class="ruby-keyword">return</span> <span class="ruby-identifier">arg</span>, []
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">if</span> <span class="ruby-constant">String</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">m</span>
<span class="ruby-identifier">m</span> = [<span class="ruby-identifier">s</span> = <span class="ruby-identifier">m</span>]
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">m</span> = <span class="ruby-identifier">m</span>.<span class="ruby-identifier">to_a</span>
<span class="ruby-identifier">s</span> = <span class="ruby-identifier">m</span>[<span class="ruby-value">0</span>]
<span class="ruby-keyword">return</span> <span class="ruby-keyword">nil</span>, <span class="ruby-identifier">m</span> <span class="ruby-keyword">unless</span> <span class="ruby-constant">String</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">s</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">raise</span> <span class="ruby-constant">InvalidArgument</span>, <span class="ruby-identifier">arg</span> <span class="ruby-keyword">unless</span> <span class="ruby-identifier">arg</span>.<span class="ruby-identifier">rindex</span>(<span class="ruby-identifier">s</span>, <span class="ruby-value">0</span>)
<span class="ruby-keyword">return</span> <span class="ruby-keyword">nil</span>, <span class="ruby-identifier">m</span> <span class="ruby-keyword">if</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">length</span> <span class="ruby-operator">==</span> <span class="ruby-identifier">arg</span>.<span class="ruby-identifier">length</span>
<span class="ruby-keyword">yield</span>(<span class="ruby-constant">InvalidArgument</span>, <span class="ruby-identifier">arg</span>) <span class="ruby-comment"># didn't match whole arg</span>
<span class="ruby-keyword">return</span> <span class="ruby-identifier">arg</span>[<span class="ruby-identifier">s</span>.<span class="ruby-identifier">length</span><span class="ruby-operator">..</span><span class="ruby-value">-1</span>], <span class="ruby-identifier">m</span>
<span class="ruby-keyword">end</span></pre>
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