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cleaned and commented the lexer (again) interpolate_string() continues to shrink

This commit is contained in:
Jeremy Ashkenas 2010-03-07 12:47:03 -05:00
parent f74fae58e3
commit 4906cf1aff
4 changed files with 403 additions and 335 deletions

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@ -36,7 +36,7 @@ to avoid having a JavaScript error at runtime.</p> </td>
be used as identifiers or properties.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">JS_FORBIDDEN: </span><span class="nx">JS_KEYWORDS</span><span class="p">.</span><span class="nx">concat</span> <span class="nx">RESERVED</span></pre></div> </td> </tr> <tr id="section-9"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-9">#</a> </div> <p>Token matching regexes.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nx">IDENTIFIER</span> <span class="o">:</span> <span class="sr">/^([a-zA-Z$_](\w|\$)*)/</span>
<span class="nx">NUMBER</span> <span class="o">:</span> <span class="sr">/^(\b((0(x|X)[0-9a-fA-F]+)|([0-9]+(\.[0-9]+)?(e[+\-]?[0-9]+)?)))\b/i</span>
<span class="nx">HEREDOC</span> <span class="o">:</span> <span class="sr">/^(&quot;{6}|&#39;{6}|&quot;{3}\n?([\s\S]*?)\n?([ \t]*)&quot;{3}|&#39;{3}\n?([\s\S]*?)\n?([ \t]*)&#39;{3})/</span>
<span class="nx">INTERPOLATION</span> <span class="o">:</span> <span class="sr">/(^|[\s\S]*?(?:[\\]|\\\\)?)\$([a-zA-Z_@]\w*|{[\s\S]*?(?:[^\\]|\\\\)})/</span>
<span class="nx">INTERPOLATION</span> <span class="o">:</span> <span class="sr">/^\$([a-zA-Z_@]\w*)/</span>
<span class="nx">OPERATOR</span> <span class="o">:</span> <span class="sr">/^([+\*&amp;|\/\-%=&lt;&gt;:!?]+)/</span>
<span class="nx">WHITESPACE</span> <span class="o">:</span> <span class="sr">/^([ \t]+)/</span>
<span class="nx">COMMENT</span> <span class="o">:</span> <span class="sr">/^(((\n?[ \t]*)?#[^\n]*)+)/</span>
@ -64,31 +64,45 @@ treated as identifiers.</p> </td> <td class="code">
occurs at the start of a line. We disambiguate these from trailing whens to
avoid an ambiguity in the grammar.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">BEFORE_WHEN: </span><span class="p">[</span><span class="s1">&#39;INDENT&#39;</span><span class="p">,</span> <span class="s1">&#39;OUTDENT&#39;</span><span class="p">,</span> <span class="s1">&#39;TERMINATOR&#39;</span><span class="p">]</span></pre></div> </td> </tr> <tr id="section-15"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-15">#</a> </div> <h2>The Lexer Class</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-16"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-16">#</a> </div> <p>The Lexer class reads a stream of CoffeeScript and divvys it up into tagged
tokens. A minor bit of the ambiguity in the grammar has been avoided by
pushing some extra smarts into the Lexer.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">exports.Lexer: </span><span class="nx">class</span> <span class="nx">Lexer</span></pre></div> </td> </tr> <tr id="section-17"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-17">#</a> </div> <p>Scan by attempting to match tokens one at a time. Slow and steady.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tokenize: </span><span class="p">(</span><span class="nx">code</span><span class="p">,</span> <span class="nx">options</span><span class="p">)</span> <span class="o">-&gt;</span>
pushing some extra smarts into the Lexer.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">exports.Lexer: </span><span class="nx">class</span> <span class="nx">Lexer</span></pre></div> </td> </tr> <tr id="section-17"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-17">#</a> </div> <p><strong>tokenize</strong> is the Lexer's main method. Scan by attempting to match tokens
one at a time, using a regular expression anchored at the start of the
remaining code, or a custom recursive token-matching method
(for interpolations). When the next token has been recorded, we move forward
within the code past the token, and begin again.</p>
<p>Each tokenizing method is responsible for incrementing <code>@i</code> by the number of
characters it has consumed. <code>@i</code> can be thought of as our finger on the page
of source.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tokenize: </span><span class="p">(</span><span class="nx">code</span><span class="p">,</span> <span class="nx">options</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">o</span> <span class="o">:</span> <span class="nx">options</span> <span class="o">or</span> <span class="p">{}</span>
<span class="err">@</span><span class="nx">code</span> <span class="o">:</span> <span class="nx">code</span> <span class="c1"># The remainder of the source code.</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">:</span> <span class="mi">0</span> <span class="c1"># Current character position we&#39;re parsing.</span>
<span class="err">@</span><span class="nx">line</span> <span class="o">:</span> <span class="nx">o</span><span class="p">.</span><span class="nx">line</span> <span class="o">or</span> <span class="mi">0</span> <span class="c1"># The current line.</span>
<span class="err">@</span><span class="nx">indent</span> <span class="o">:</span> <span class="mi">0</span> <span class="c1"># The current indent level.</span>
<span class="err">@</span><span class="nx">indents</span> <span class="o">:</span> <span class="p">[]</span> <span class="c1"># The stack of all indent levels we are currently within.</span>
<span class="err">@</span><span class="nx">tokens</span> <span class="o">:</span> <span class="p">[]</span> <span class="c1"># Collection of all parsed tokens in the form [&#39;TOKEN_TYPE&#39;, value, line]</span>
<span class="err">@</span><span class="nx">indent</span> <span class="o">:</span> <span class="mi">0</span> <span class="c1"># The current indentation level.</span>
<span class="err">@</span><span class="nx">indents</span> <span class="o">:</span> <span class="p">[]</span> <span class="c1"># The stack of all current indentation levels.</span>
<span class="err">@</span><span class="nx">tokens</span> <span class="o">:</span> <span class="p">[]</span> <span class="c1"># Stream of parsed tokens in the form [&#39;TYPE&#39;, value, line]</span>
<span class="k">while</span> <span class="err">@</span><span class="nx">i</span> <span class="o">&lt;</span> <span class="err">@</span><span class="nx">code</span><span class="p">.</span><span class="nx">length</span>
<span class="err">@</span><span class="nv">chunk: </span><span class="err">@</span><span class="nx">code</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="err">@</span><span class="nx">i</span><span class="p">)</span>
<span class="err">@</span><span class="nx">extract_next_token</span><span class="p">()</span>
<span class="err">@</span><span class="nx">close_indentation</span><span class="p">()</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">tokens</span> <span class="k">if</span> <span class="nx">o</span><span class="p">.</span><span class="nx">rewrite</span> <span class="o">is</span> <span class="kc">no</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">tokens</span> <span class="k">if</span> <span class="nx">o</span><span class="p">.</span><span class="nx">rewrite</span> <span class="o">is</span> <span class="kc">off</span>
<span class="p">(</span><span class="k">new</span> <span class="nx">Rewriter</span><span class="p">()).</span><span class="nx">rewrite</span> <span class="err">@</span><span class="nx">tokens</span></pre></div> </td> </tr> <tr id="section-18"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-18">#</a> </div> <p>At every position, run through this list of attempted matches,
short-circuiting if any of them succeed.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">extract_next_token: </span><span class="o">-&gt;</span>
short-circuiting if any of them succeed. Their order determines precedence:
<code>@literal_token</code> is the fallback catch-all.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">extract_next_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">identifier_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">number_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">heredoc_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">string_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">js_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">regex_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">comment_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">line_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">whitespace_token</span><span class="p">()</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">literal_token</span><span class="p">()</span></pre></div> </td> </tr> <tr id="section-19"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-19">#</a> </div> <h2>Tokenizers</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-20"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-20">#</a> </div> <p>Matches identifying literals: variables, keywords, method names, etc.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">identifier_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">js_token</span><span class="p">()</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">string_token</span><span class="p">()</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">literal_token</span><span class="p">()</span></pre></div> </td> </tr> <tr id="section-19"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-19">#</a> </div> <h2>Tokenizers</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-20"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-20">#</a> </div> <p>Matches identifying literals: variables, keywords, method names, etc.
Check to ensure that JavaScript reserved words aren't being used as
identifiers. Because CoffeeScript reserves a handful of keywords that are
allowed in JavaScript, we're careful not to tag them as keywords when
referenced as property names here, so you can still do <code>jQuery.is()</code> even
though <code>is</code> means <code>===</code> otherwise.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">identifier_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">id: </span><span class="err">@</span><span class="nx">match</span> <span class="nx">IDENTIFIER</span><span class="p">,</span> <span class="mi">1</span>
<span class="err">@</span><span class="nx">name_access_type</span><span class="p">()</span>
<span class="nv">tag: </span><span class="s1">&#39;IDENTIFIER&#39;</span>
@ -102,60 +116,55 @@ short-circuiting if any of them succeed.</p> </td> <td c
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">number: </span><span class="err">@</span><span class="nx">match</span> <span class="nx">NUMBER</span><span class="p">,</span> <span class="mi">1</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;NUMBER&#39;</span><span class="p">,</span> <span class="nx">number</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">number</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-22"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-22">#</a> </div> <p>Matches strings, including multi-line strings.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">string_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-22"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-22">#</a> </div> <p>Matches strings, including multi-line strings. Ensures that quotation marks
are balanced within the string's contents, and within nested interpolations.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">string_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nx">starts</span><span class="p">(</span><span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="s1">&#39;&quot;&#39;</span><span class="p">)</span> <span class="o">or</span> <span class="nx">starts</span><span class="p">(</span><span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="s2">&quot;&#39;&quot;</span><span class="p">)</span>
<span class="nv">string: </span><span class="err">@</span><span class="nx">balanced_token</span> <span class="p">[</span><span class="s1">&#39;&quot;&#39;</span><span class="p">,</span> <span class="s1">&#39;&quot;&#39;</span><span class="p">],</span> <span class="p">[</span><span class="s1">&#39;${&#39;</span><span class="p">,</span> <span class="s1">&#39;}&#39;</span><span class="p">]</span>
<span class="nv">string: </span><span class="err">@</span><span class="nx">balanced_token</span> <span class="p">[</span><span class="s2">&quot;&#39;&quot;</span><span class="p">,</span> <span class="s2">&quot;&#39;&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">string</span> <span class="o">is</span> <span class="kc">false</span>
<span class="nv">string: </span><span class="err">@</span><span class="nx">balanced_token</span> <span class="p">[</span><span class="s2">&quot;&#39;&quot;</span><span class="p">,</span> <span class="s2">&quot;&#39;&quot;</span><span class="p">]</span> <span class="nx">unless</span> <span class="nx">string</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nx">string</span>
<span class="err">@</span><span class="nx">interpolate_string</span> <span class="nx">string</span><span class="p">.</span><span class="nx">replace</span> <span class="nx">STRING_NEWLINES</span><span class="p">,</span> <span class="s2">&quot; \\\n&quot;</span>
<span class="err">@</span><span class="nx">line</span> <span class="o">+=</span> <span class="nx">count</span> <span class="nx">string</span><span class="p">,</span> <span class="s2">&quot;\n&quot;</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">string</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-23"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-23">#</a> </div> <p>Matches heredocs, adjusting indentation to the correct level.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">heredoc_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-23"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-23">#</a> </div> <p>Matches heredocs, adjusting indentation to the correct level, as heredocs
preserve whitespace, but ignore indentation to the left.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">heredoc_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nx">match</span> <span class="o">=</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">HEREDOC</span><span class="p">)</span>
<span class="nv">doc: </span><span class="err">@</span><span class="nx">sanitize_heredoc</span> <span class="nx">match</span><span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="o">or</span> <span class="nx">match</span><span class="p">[</span><span class="mi">4</span><span class="p">]</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;\&quot;$doc\&quot;&quot;</span>
<span class="err">@</span><span class="nx">line</span> <span class="o">+=</span> <span class="nx">count</span> <span class="nx">match</span><span class="p">[</span><span class="mi">1</span><span class="p">],</span> <span class="s2">&quot;\n&quot;</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">match</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-24"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-24">#</a> </div> <p>Matches interpolated JavaScript.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">js_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-24"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-24">#</a> </div> <p>Matches JavaScript interpolated directly into the source via backticks.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">js_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nx">starts</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="s1">&#39;`&#39;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">script: </span><span class="err">@</span><span class="nx">balanced_token</span> <span class="p">[</span><span class="s1">&#39;`&#39;</span><span class="p">,</span> <span class="s1">&#39;`&#39;</span><span class="p">]</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;JS&#39;</span><span class="p">,</span> <span class="nx">script</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">JS_CLEANER</span><span class="p">,</span> <span class="s1">&#39;&#39;</span><span class="p">)</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">script</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-25"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-25">#</a> </div> <p>Matches regular expression literals.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">regex_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-25"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-25">#</a> </div> <p>Matches regular expression literals. Lexing regular expressions is difficult
to distinguish from division, so we borrow some basic heuristics from
JavaScript and Ruby.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">regex_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">regex: </span><span class="err">@</span><span class="nx">match</span> <span class="nx">REGEX</span><span class="p">,</span> <span class="mi">1</span>
<span class="k">return</span> <span class="kc">false</span> <span class="k">if</span> <span class="nx">include</span> <span class="nx">NOT_REGEX</span><span class="p">,</span> <span class="err">@</span><span class="nx">tag</span><span class="p">()</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;REGEX&#39;</span><span class="p">,</span> <span class="nx">regex</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">regex</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-26"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-26">#</a> </div> <p>Matches a balanced group such as a single or double-quoted string. Pass in
a series of delimiters, all of which must be balanced correctly within the
token's contents.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">balanced_token: </span><span class="p">(</span><span class="nx">delimited</span><span class="p">...)</span> <span class="o">-&gt;</span>
<span class="nv">levels: </span><span class="p">[]</span>
<span class="nv">i: </span><span class="mi">0</span>
<span class="k">while</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">.</span><span class="nx">length</span>
<span class="k">for</span> <span class="nx">pair</span> <span class="k">in</span> <span class="nx">delimited</span>
<span class="p">[</span><span class="nx">open</span><span class="p">,</span> <span class="nx">close</span><span class="p">]</span><span class="o">:</span> <span class="nx">pair</span>
<span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">and</span> <span class="nx">starts</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="s1">&#39;\\&#39;</span><span class="p">,</span> <span class="nx">i</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">break</span>
<span class="k">else</span> <span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">and</span> <span class="nx">starts</span><span class="p">(</span><span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="nx">close</span><span class="p">,</span> <span class="nx">i</span><span class="p">)</span> <span class="o">and</span> <span class="nx">levels</span><span class="p">[</span><span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">]</span> <span class="o">is</span> <span class="nx">pair</span>
<span class="nx">levels</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">close</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span> <span class="nx">unless</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="k">break</span>
<span class="k">else</span> <span class="k">if</span> <span class="nx">starts</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="nx">open</span><span class="p">,</span> <span class="nx">i</span>
<span class="nx">levels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">pair</span><span class="p">)</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">open</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="k">break</span>
<span class="k">break</span> <span class="nx">unless</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}&quot;</span> <span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="k">return</span> <span class="kc">false</span> <span class="k">if</span> <span class="nx">i</span> <span class="o">is</span> <span class="mi">0</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nx">i</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-27"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-27">#</a> </div> <p>Matches and conumes comments.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">comment_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-26"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-26">#</a> </div> <p>Matches a token in which which the passed delimiter pairs must be correctly
balanced (ie. strings, JS literals).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">balanced_token: </span><span class="p">(</span><span class="nx">delimited</span><span class="p">...)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">balanced_string</span> <span class="err">@</span><span class="nx">chunk</span><span class="p">,</span> <span class="nx">delimited</span><span class="p">...</span></pre></div> </td> </tr> <tr id="section-27"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-27">#</a> </div> <p>Matches and conumes comments. We pass through comments into JavaScript,
so they're treated as real tokens, like any other part of the language.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">comment_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">comment: </span><span class="err">@</span><span class="nx">match</span> <span class="nx">COMMENT</span><span class="p">,</span> <span class="mi">1</span>
<span class="err">@</span><span class="nx">line</span> <span class="o">+=</span> <span class="p">(</span><span class="nx">comment</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">MULTILINER</span><span class="p">)</span> <span class="o">or</span> <span class="p">[]).</span><span class="nx">length</span>
<span class="nv">lines: </span><span class="nx">comment</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">COMMENT_CLEANER</span><span class="p">,</span> <span class="s1">&#39;&#39;</span><span class="p">).</span><span class="nx">split</span><span class="p">(</span><span class="nx">MULTILINER</span><span class="p">)</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;COMMENT&#39;</span><span class="p">,</span> <span class="nx">compact</span> <span class="nx">lines</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;TERMINATOR&#39;</span><span class="p">,</span> <span class="s2">&quot;\n&quot;</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">comment</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-28"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-28">#</a> </div> <p>Matches newlines, indents, and outdents, and determines which is which.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">line_token: </span><span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-28"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-28">#</a> </div> <p>Matches newlines, indents, and outdents, and determines which is which.
If we can detect that the current line is continued onto the the next line,
then the newline is suppressed:</p>
<pre><code>elements
.each( ... )
.map( ... )
</code></pre>
<p>Keeps track of the level of indentation, because a single outdent token
can close multiple indents, so we need to know how far in we happen to be.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">line_token: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">indent: </span><span class="err">@</span><span class="nx">match</span> <span class="nx">MULTI_DENT</span><span class="p">,</span> <span class="mi">1</span>
<span class="err">@</span><span class="nx">line</span> <span class="o">+=</span> <span class="nx">indent</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">MULTILINER</span><span class="p">).</span><span class="nx">length</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">indent</span><span class="p">.</span><span class="nx">length</span>
@ -165,18 +174,18 @@ token's contents.</p> </td> <td class="code">
<span class="nv">no_newlines: </span><span class="nx">next_character</span> <span class="o">is</span> <span class="s1">&#39;.&#39;</span> <span class="o">or</span> <span class="p">(</span><span class="err">@</span><span class="nx">value</span><span class="p">()</span> <span class="o">and</span> <span class="err">@</span><span class="nx">value</span><span class="p">().</span><span class="nx">match</span><span class="p">(</span><span class="nx">NO_NEWLINE</span><span class="p">)</span> <span class="o">and</span>
<span class="nx">prev</span> <span class="o">and</span> <span class="p">(</span><span class="nx">prev</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">isnt</span> <span class="s1">&#39;.&#39;</span><span class="p">)</span> <span class="o">and</span> <span class="o">not</span> <span class="err">@</span><span class="nx">value</span><span class="p">().</span><span class="nx">match</span><span class="p">(</span><span class="nx">CODE</span><span class="p">))</span>
<span class="k">if</span> <span class="nx">size</span> <span class="o">is</span> <span class="err">@</span><span class="nx">indent</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">suppress_newlines</span><span class="p">(</span><span class="nx">indent</span><span class="p">)</span> <span class="k">if</span> <span class="nx">no_newlines</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">suppress_newlines</span><span class="p">()</span> <span class="k">if</span> <span class="nx">no_newlines</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">newline_token</span><span class="p">(</span><span class="nx">indent</span><span class="p">)</span>
<span class="k">else</span> <span class="k">if</span> <span class="nx">size</span> <span class="o">&gt;</span> <span class="err">@</span><span class="nx">indent</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">suppress_newlines</span><span class="p">(</span><span class="nx">indent</span><span class="p">)</span> <span class="k">if</span> <span class="nx">no_newlines</span>
<span class="k">return</span> <span class="err">@</span><span class="nx">suppress_newlines</span><span class="p">()</span> <span class="k">if</span> <span class="nx">no_newlines</span>
<span class="nv">diff: </span><span class="nx">size</span> <span class="o">-</span> <span class="err">@</span><span class="nx">indent</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;INDENT&#39;</span><span class="p">,</span> <span class="nx">diff</span>
<span class="err">@</span><span class="nx">indents</span><span class="p">.</span><span class="nx">push</span> <span class="nx">diff</span>
<span class="k">else</span>
<span class="err">@</span><span class="nx">outdent_token</span> <span class="err">@</span><span class="nx">indent</span> <span class="o">-</span> <span class="nx">size</span><span class="p">,</span> <span class="nx">no_newlines</span>
<span class="err">@</span><span class="nv">indent: </span><span class="nx">size</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-29"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-29">#</a> </div> <p>Record an outdent token or tokens, if we happen to be moving back inwards
past multiple recorded indents.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">outdent_token: </span><span class="p">(</span><span class="nx">move_out</span><span class="p">,</span> <span class="nx">no_newlines</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-29"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-29">#</a> </div> <p>Record an outdent token or multiple tokens, if we happen to be moving back
inwards past several recorded indents.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">outdent_token: </span><span class="p">(</span><span class="nx">move_out</span><span class="p">,</span> <span class="nx">no_newlines</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">while</span> <span class="nx">move_out</span> <span class="o">&gt;</span> <span class="mi">0</span> <span class="o">and</span> <span class="err">@</span><span class="nx">indents</span><span class="p">.</span><span class="nx">length</span>
<span class="nv">last_indent: </span><span class="err">@</span><span class="nx">indents</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;OUTDENT&#39;</span><span class="p">,</span> <span class="nx">last_indent</span>
@ -188,14 +197,16 @@ as being "spaced", because there are some cases where it makes a difference.</p>
<span class="nv">prev: </span><span class="err">@</span><span class="nx">prev</span><span class="p">()</span>
<span class="nv">prev.spaced: </span><span class="kc">true</span> <span class="k">if</span> <span class="nx">prev</span>
<span class="err">@</span><span class="nx">i</span> <span class="o">+=</span> <span class="nx">space</span><span class="p">.</span><span class="nx">length</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-31"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-31">#</a> </div> <p>Generate a newline token. Multiple newlines get merged together.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">newline_token: </span><span class="p">(</span><span class="nx">newlines</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-31"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-31">#</a> </div> <p>Generate a newline token. Consecutive newlines get merged together.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">newline_token: </span><span class="p">(</span><span class="nx">newlines</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;TERMINATOR&#39;</span><span class="p">,</span> <span class="s2">&quot;\n&quot;</span> <span class="nx">unless</span> <span class="err">@</span><span class="nx">tag</span><span class="p">()</span> <span class="o">is</span> <span class="s1">&#39;TERMINATOR&#39;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-32"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-32">#</a> </div> <p>Use a <code>\</code> at a line-ending to suppress the newline.
The slash is removed here once its job is done.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">suppress_newlines: </span><span class="p">(</span><span class="nx">newlines</span><span class="p">)</span> <span class="o">-&gt;</span>
The slash is removed here once its job is done.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">suppress_newlines: </span><span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span> <span class="k">if</span> <span class="err">@</span><span class="nx">value</span><span class="p">()</span> <span class="o">is</span> <span class="s2">&quot;\\&quot;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-33"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-33">#</a> </div> <p>We treat all other single characters as a token. Eg.: <code>( ) , . !</code>
Multi-character operators are also literal tokens, so that Jison can assign
the proper order of operations.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">literal_token: </span><span class="o">-&gt;</span>
the proper order of operations. There are some symbols that we tag specially
here. <code>;</code> and newlines are both treated as a <code>TERMINATOR</code>, we distinguish
parentheses that indicate a method call from regular parentheses, and so on.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">literal_token: </span><span class="o">-&gt;</span>
<span class="nv">match: </span><span class="err">@</span><span class="nx">chunk</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">OPERATOR</span><span class="p">)</span>
<span class="nv">value: </span><span class="nx">match</span> <span class="o">and</span> <span class="nx">match</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
<span class="err">@</span><span class="nx">tag_parameters</span><span class="p">()</span> <span class="k">if</span> <span class="nx">value</span> <span class="o">and</span> <span class="nx">value</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">CODE</span><span class="p">)</span>
@ -227,15 +238,14 @@ if it's a special kind of accessor.</p> </td> <td class=
<span class="err">@</span><span class="nx">tag</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;SOAK_ACCESS&#39;</span><span class="p">)</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">splice</span><span class="p">(</span><span class="o">-</span><span class="mi">2</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span>
<span class="k">else</span>
<span class="err">@</span><span class="nx">tag</span> <span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;PROPERTY_ACCESS&#39;</span></pre></div> </td> </tr> <tr id="section-36"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-36">#</a> </div> <p>Sanitize a heredoc by escaping double quotes and erasing all external
indentation on the left-hand side.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">sanitize_heredoc: </span><span class="p">(</span><span class="nx">doc</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tag</span> <span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;PROPERTY_ACCESS&#39;</span></pre></div> </td> </tr> <tr id="section-36"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-36">#</a> </div> <p>Sanitize a heredoc by escaping internal double quotes and erasing all
external indentation on the left-hand side.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">sanitize_heredoc: </span><span class="p">(</span><span class="nx">doc</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">indent: </span><span class="p">(</span><span class="nx">doc</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">HEREDOC_INDENT</span><span class="p">)</span> <span class="o">or</span> <span class="p">[</span><span class="s1">&#39;&#39;</span><span class="p">]).</span><span class="nx">sort</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span>
<span class="nx">doc</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="k">new</span> <span class="nb">RegExp</span><span class="p">(</span><span class="s2">&quot;^&quot;</span> <span class="o">+</span><span class="nx">indent</span><span class="p">,</span> <span class="s1">&#39;gm&#39;</span><span class="p">),</span> <span class="s1">&#39;&#39;</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">MULTILINER</span><span class="p">,</span> <span class="s2">&quot;\\n&quot;</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/&quot;/g</span><span class="p">,</span> <span class="s1">&#39;\\&quot;&#39;</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-37"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-37">#</a> </div> <p>A source of ambiguity in our grammar was parameter lists in function
definitions (as opposed to argument lists in function calls). Tag
parameter identifiers in order to avoid this. Also, parameter lists can
make use of splats.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tag_parameters: </span><span class="o">-&gt;</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/&quot;/g</span><span class="p">,</span> <span class="s1">&#39;\\&quot;&#39;</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-37"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-37">#</a> </div> <p>A source of ambiguity in our grammar used to be parameter lists in function
definitions versus argument lists in function calls. Walk backwards, tagging
parameters specially in order to make things easier for the parser.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tag_parameters: </span><span class="o">-&gt;</span>
<span class="k">return</span> <span class="k">if</span> <span class="err">@</span><span class="nx">tag</span><span class="p">()</span> <span class="o">isnt</span> <span class="s1">&#39;)&#39;</span>
<span class="nv">i: </span><span class="mi">0</span>
<span class="k">while</span> <span class="kc">true</span>
@ -247,69 +257,92 @@ make use of splats.</p> </td> <td class="code">
<span class="k">when</span> <span class="s1">&#39;)&#39;</span> <span class="k">then</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">:</span> <span class="s1">&#39;PARAM_END&#39;</span>
<span class="k">when</span> <span class="s1">&#39;(&#39;</span> <span class="k">then</span> <span class="k">return</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">:</span> <span class="s1">&#39;PARAM_START&#39;</span>
<span class="kc">true</span></pre></div> </td> </tr> <tr id="section-38"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-38">#</a> </div> <p>Close up all remaining open blocks at the end of the file.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">close_indentation: </span><span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">outdent_token</span><span class="p">(</span><span class="err">@</span><span class="nx">indent</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-39"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-39">#</a> </div> <p>Error for when you try to use a forbidden word in JavaScript as
<span class="err">@</span><span class="nx">outdent_token</span><span class="p">(</span><span class="err">@</span><span class="nx">indent</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-39"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-39">#</a> </div> <p>The error for when you try to use a forbidden word in JavaScript as
an identifier.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">identifier_error: </span><span class="p">(</span><span class="nx">word</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Reserved word \&quot;$word\&quot; on line ${@line + 1}&quot;</span></pre></div> </td> </tr> <tr id="section-40"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-40">#</a> </div> <p>Error for when you try to assign to a reserved word in JavaScript,
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Reserved word \&quot;$word\&quot; on line ${@line + 1}&quot;</span></pre></div> </td> </tr> <tr id="section-40"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-40">#</a> </div> <p>The error for when you try to assign to a reserved word in JavaScript,
like "function" or "default".</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">assignment_error: </span><span class="o">-&gt;</span>
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Reserved word \&quot;${@value()}\&quot; on line ${@line + 1} can&#39;t be assigned&quot;</span></pre></div> </td> </tr> <tr id="section-41"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-41">#</a> </div> <p>Expand variables and expressions inside double-quoted strings using
<a href="http://wiki.ecmascript.org/doku.php?id=strawman:string_interpolation">ECMA Harmony's interpolation syntax</a>.</p>
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Reserved word \&quot;${@value()}\&quot; on line ${@line + 1} can&#39;t be assigned&quot;</span></pre></div> </td> </tr> <tr id="section-41"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-41">#</a> </div> <p>Matches a balanced group such as a single or double-quoted string. Pass in
a series of delimiters, all of which must be nested correctly within the
contents of the string. This method allows us to have strings within
interpolations within strings etc...</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">balanced_string: </span><span class="p">(</span><span class="nx">str</span><span class="p">,</span> <span class="nx">delimited</span><span class="p">...)</span> <span class="o">-&gt;</span>
<span class="nv">levels: </span><span class="p">[]</span>
<span class="nv">i: </span><span class="mi">0</span>
<span class="k">while</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span>
<span class="k">for</span> <span class="nx">pair</span> <span class="k">in</span> <span class="nx">delimited</span>
<span class="p">[</span><span class="nx">open</span><span class="p">,</span> <span class="nx">close</span><span class="p">]</span><span class="o">:</span> <span class="nx">pair</span>
<span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">and</span> <span class="nx">starts</span> <span class="nx">str</span><span class="p">,</span> <span class="s1">&#39;\\&#39;</span><span class="p">,</span> <span class="nx">i</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">break</span>
<span class="k">else</span> <span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">and</span> <span class="nx">starts</span><span class="p">(</span><span class="nx">str</span><span class="p">,</span> <span class="nx">close</span><span class="p">,</span> <span class="nx">i</span><span class="p">)</span> <span class="o">and</span> <span class="nx">levels</span><span class="p">[</span><span class="nx">levels</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">]</span> <span class="o">is</span> <span class="nx">pair</span>
<span class="nx">levels</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">close</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span> <span class="nx">unless</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="k">break</span>
<span class="k">else</span> <span class="k">if</span> <span class="nx">starts</span> <span class="nx">str</span><span class="p">,</span> <span class="nx">open</span><span class="p">,</span> <span class="nx">i</span>
<span class="nx">levels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">pair</span><span class="p">)</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">open</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="k">break</span>
<span class="k">break</span> <span class="nx">unless</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span> <span class="s2">&quot;SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}&quot;</span> <span class="k">if</span> <span class="nx">levels</span><span class="p">.</span><span class="nx">length</span>
<span class="k">return</span> <span class="kc">false</span> <span class="k">if</span> <span class="nx">i</span> <span class="o">is</span> <span class="mi">0</span>
<span class="k">return</span> <span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nx">i</span><span class="p">)</span></pre></div> </td> </tr> <tr id="section-42"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-42">#</a> </div> <p>Expand variables and expressions inside double-quoted strings using
<a href="http://wiki.ecmascript.org/doku.php?id=strawman:string_interpolation">ECMA Harmony's interpolation syntax</a>
for substitution of bare variables as well as arbitrary expressions.</p>
<pre><code>"Hello $name."
"Hello ${name.capitalize()}."
</code></pre> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">interpolate_string: </span><span class="p">(</span><span class="nx">str</span><span class="p">)</span> <span class="o">-&gt;</span>
</code></pre>
<p>If it encounters an interpolation, this method will recursively create a
new Lexer, tokenize the interpolated contents, and merge them into the
token stream.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">interpolate_string: </span><span class="p">(</span><span class="nx">str</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">if</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span> <span class="o">&lt;</span> <span class="mi">3</span> <span class="o">or</span> <span class="o">not</span> <span class="nx">starts</span> <span class="nx">str</span><span class="p">,</span> <span class="s1">&#39;&quot;&#39;</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="nx">str</span>
<span class="k">else</span>
<span class="nv">lexer: </span> <span class="k">new</span> <span class="nx">Lexer</span><span class="p">()</span>
<span class="nv">tokens: </span><span class="p">[]</span>
<span class="nv">quote: </span> <span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span>
<span class="nv">str: </span> <span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<span class="k">while</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span>
<span class="nv">match: </span><span class="nx">str</span><span class="p">.</span><span class="nx">match</span> <span class="nx">INTERPOLATION</span>
<span class="k">if</span> <span class="nx">match</span>
<span class="p">[</span><span class="nx">group</span><span class="p">,</span> <span class="nx">before</span><span class="p">,</span> <span class="nx">interp</span><span class="p">]</span><span class="o">:</span> <span class="nx">match</span>
<span class="k">if</span> <span class="nx">starts</span> <span class="nx">before</span><span class="p">,</span> <span class="s1">&#39;\\&#39;</span><span class="p">,</span> <span class="nx">before</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="nv">prev: </span><span class="nx">before</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nx">before</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote$prev$$interp$quote&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">before</span><span class="p">.</span><span class="nx">length</span>
<span class="k">else</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote$before$quote&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">before</span><span class="p">.</span><span class="nx">length</span>
<span class="k">if</span> <span class="nx">starts</span> <span class="nx">interp</span><span class="p">,</span> <span class="s1">&#39;{&#39;</span>
<span class="nv">inner: </span><span class="nx">interp</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="nx">interp</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<span class="nv">nested: </span><span class="nx">lexer</span><span class="p">.</span><span class="nx">tokenize</span> <span class="s2">&quot;($inner)&quot;</span><span class="p">,</span> <span class="p">{</span><span class="nv">rewrite: </span><span class="kc">no</span><span class="p">,</span> <span class="nv">line: </span><span class="err">@</span><span class="nx">line</span><span class="p">}</span>
<span class="nx">nested</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;TOKENS&#39;</span><span class="p">,</span> <span class="nx">nested</span><span class="p">]</span>
<span class="k">else</span>
<span class="nv">interp: </span><span class="s2">&quot;this.${ interp.substring(1) }&quot;</span> <span class="k">if</span> <span class="nx">starts</span> <span class="nx">interp</span><span class="p">,</span> <span class="s1">&#39;@&#39;</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;IDENTIFIER&#39;</span><span class="p">,</span> <span class="nx">interp</span><span class="p">]</span>
<span class="nv">str: </span><span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">group</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span>
<span class="k">else</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote$str$quote&quot;</span><span class="p">]</span>
<span class="nv">str: </span><span class="s1">&#39;&#39;</span>
<span class="k">if</span> <span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">&gt;</span> <span class="mi">1</span>
<span class="k">for</span> <span class="nx">i</span> <span class="k">in</span> <span class="p">[</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">..</span><span class="mi">1</span><span class="p">]</span>
<span class="p">[</span><span class="nx">prev</span><span class="p">,</span> <span class="nx">tok</span><span class="p">]</span><span class="o">:</span> <span class="p">[</span><span class="nx">tokens</span><span class="p">[</span><span class="nx">i</span> <span class="o">-</span> <span class="mi">1</span><span class="p">],</span> <span class="nx">tokens</span><span class="p">[</span><span class="nx">i</span><span class="p">]]</span>
<span class="k">if</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">is</span> <span class="s1">&#39;STRING&#39;</span> <span class="o">and</span> <span class="nx">prev</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">is</span> <span class="s1">&#39;STRING&#39;</span>
<span class="p">[</span><span class="nx">prev</span><span class="p">,</span> <span class="nx">tok</span><span class="p">]</span><span class="o">:</span> <span class="p">[</span><span class="nx">prev</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="nx">substring</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="nx">prev</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">),</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="nx">substring</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)]</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">splice</span> <span class="nx">i</span> <span class="o">-</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote$prev$tok$quote&quot;</span><span class="p">]</span>
<span class="nv">lexer: </span> <span class="k">new</span> <span class="nx">Lexer</span><span class="p">()</span>
<span class="nv">tokens: </span> <span class="p">[]</span>
<span class="nv">quote: </span> <span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span>
<span class="p">[</span><span class="nx">i</span><span class="p">,</span> <span class="nx">pi</span><span class="p">]</span><span class="o">:</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">]</span>
<span class="k">while</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="k">if</span> <span class="nx">starts</span> <span class="nx">str</span><span class="p">,</span> <span class="s1">&#39;\\&#39;</span><span class="p">,</span> <span class="nx">i</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">else</span> <span class="k">if</span> <span class="nv">match: </span><span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">i</span><span class="p">).</span><span class="nx">match</span> <span class="nx">INTERPOLATION</span>
<span class="p">[</span><span class="nx">group</span><span class="p">,</span> <span class="nx">interp</span><span class="p">]</span><span class="o">:</span> <span class="nx">match</span>
<span class="nv">interp: </span><span class="s2">&quot;this.${ interp.substring(1) }&quot;</span> <span class="k">if</span> <span class="nx">starts</span> <span class="nx">interp</span><span class="p">,</span> <span class="s1">&#39;@&#39;</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote${ str.substring(pi, i) }$quote&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">pi</span> <span class="o">&lt;</span> <span class="nx">i</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;IDENTIFIER&#39;</span><span class="p">,</span> <span class="nx">interp</span><span class="p">]</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">group</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="nv">pi: </span><span class="nx">i</span> <span class="o">+</span> <span class="mi">1</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nv">expr: </span><span class="err">@</span><span class="nx">balanced_string</span> <span class="nx">str</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">i</span><span class="p">),</span> <span class="p">[</span><span class="s1">&#39;${&#39;</span><span class="p">,</span> <span class="s1">&#39;}&#39;</span><span class="p">])</span> <span class="o">and</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">length</span> <span class="o">&gt;</span> <span class="mi">3</span>
<span class="nv">inner: </span><span class="nx">expr</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<span class="nv">nested: </span><span class="nx">lexer</span><span class="p">.</span><span class="nx">tokenize</span> <span class="s2">&quot;($inner)&quot;</span><span class="p">,</span> <span class="p">{</span><span class="nv">rewrite: </span><span class="kc">no</span><span class="p">,</span> <span class="nv">line: </span><span class="err">@</span><span class="nx">line</span><span class="p">}</span>
<span class="nx">nested</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote${ str.substring(pi, i) }$quote&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">pi</span> <span class="o">&lt;</span> <span class="nx">i</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;TOKENS&#39;</span><span class="p">,</span> <span class="nx">nested</span><span class="p">]</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="nv">pi: </span><span class="nx">i</span> <span class="o">+</span> <span class="mi">1</span>
<span class="nx">i</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span> <span class="p">[</span><span class="s1">&#39;STRING&#39;</span><span class="p">,</span> <span class="s2">&quot;$quote${ str.substring(pi, i) }$quote&quot;</span><span class="p">]</span> <span class="k">if</span> <span class="nx">pi</span> <span class="o">&lt;</span> <span class="nx">i</span> <span class="o">and</span> <span class="nx">pi</span> <span class="o">&lt;</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span>
<span class="k">for</span> <span class="nx">each</span><span class="p">,</span> <span class="nx">i</span> <span class="k">in</span> <span class="nx">tokens</span>
<span class="k">if</span> <span class="nx">each</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">is</span> <span class="s1">&#39;TOKENS&#39;</span>
<span class="err">@</span><span class="nx">token</span> <span class="nx">nested</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="nx">nested</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="k">for</span> <span class="nx">nested</span> <span class="k">in</span> <span class="nx">each</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
<span class="err">@</span><span class="nv">tokens: </span><span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">concat</span> <span class="nx">each</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
<span class="k">else</span>
<span class="err">@</span><span class="nx">token</span> <span class="nx">each</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="nx">each</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;+&#39;</span><span class="p">,</span> <span class="s1">&#39;+&#39;</span> <span class="k">if</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span></pre></div> </td> </tr> <tr id="section-42"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-42">#</a> </div> <h2>Helpers</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-43"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-43">#</a> </div> <p>Add a token to the results, taking note of the line number.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">token: </span><span class="p">(</span><span class="nx">tag</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span><span class="p">([</span><span class="nx">tag</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="err">@</span><span class="nx">line</span><span class="p">])</span></pre></div> </td> </tr> <tr id="section-44"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-44">#</a> </div> <p>Peek at a tag in the current token stream.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tag: </span><span class="p">(</span><span class="nx">index</span><span class="p">,</span> <span class="nx">tag</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">token</span> <span class="s1">&#39;+&#39;</span><span class="p">,</span> <span class="s1">&#39;+&#39;</span> <span class="k">if</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span></pre></div> </td> </tr> <tr id="section-43"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-43">#</a> </div> <h2>Helpers</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-44"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-44">#</a> </div> <p>Add a token to the results, taking note of the line number.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">token: </span><span class="p">(</span><span class="nx">tag</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">push</span><span class="p">([</span><span class="nx">tag</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="err">@</span><span class="nx">line</span><span class="p">])</span></pre></div> </td> </tr> <tr id="section-45"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-45">#</a> </div> <p>Peek at a tag in the current token stream.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">tag: </span><span class="p">(</span><span class="nx">index</span><span class="p">,</span> <span class="nx">tag</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">return</span> <span class="nx">unless</span> <span class="nv">tok: </span><span class="err">@</span><span class="nx">prev</span><span class="p">(</span><span class="nx">index</span><span class="p">)</span>
<span class="k">return</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">:</span> <span class="nx">tag</span> <span class="k">if</span> <span class="nx">tag</span><span class="o">?</span>
<span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span></pre></div> </td> </tr> <tr id="section-45"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-45">#</a> </div> <p>Peek at a value in the current token stream.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">value: </span><span class="p">(</span><span class="nx">index</span><span class="p">,</span> <span class="nx">val</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">tok</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span></pre></div> </td> </tr> <tr id="section-46"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-46">#</a> </div> <p>Peek at a value in the current token stream.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">value: </span><span class="p">(</span><span class="nx">index</span><span class="p">,</span> <span class="nx">val</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">return</span> <span class="nx">unless</span> <span class="nv">tok: </span><span class="err">@</span><span class="nx">prev</span><span class="p">(</span><span class="nx">index</span><span class="p">)</span>
<span class="k">return</span> <span class="nx">tok</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">:</span> <span class="nx">val</span> <span class="k">if</span> <span class="nx">val</span><span class="o">?</span>
<span class="nx">tok</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span></pre></div> </td> </tr> <tr id="section-46"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-46">#</a> </div> <p>Peek at a previous token, entire.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">prev: </span><span class="p">(</span><span class="nx">index</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">[</span><span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="p">(</span><span class="nx">index</span> <span class="o">or</span> <span class="mi">1</span><span class="p">)]</span></pre></div> </td> </tr> <tr id="section-47"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-47">#</a> </div> <p>Attempt to match a string against the current chunk, returning the indexed
<span class="nx">tok</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span></pre></div> </td> </tr> <tr id="section-47"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-47">#</a> </div> <p>Peek at a previous token, entire.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">prev: </span><span class="p">(</span><span class="nx">index</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="err">@</span><span class="nx">tokens</span><span class="p">[</span><span class="err">@</span><span class="nx">tokens</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="p">(</span><span class="nx">index</span> <span class="o">or</span> <span class="mi">1</span><span class="p">)]</span></pre></div> </td> </tr> <tr id="section-48"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-48">#</a> </div> <p>Attempt to match a string against the current chunk, returning the indexed
match if successful, and <code>false</code> otherwise.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nv">match: </span><span class="p">(</span><span class="nx">regex</span><span class="p">,</span> <span class="nx">index</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">return</span> <span class="kc">false</span> <span class="nx">unless</span> <span class="nv">m: </span><span class="err">@</span><span class="nx">chunk</span><span class="p">.</span><span class="nx">match</span><span class="p">(</span><span class="nx">regex</span><span class="p">)</span>
<span class="k">if</span> <span class="nx">m</span> <span class="k">then</span> <span class="nx">m</span><span class="p">[</span><span class="nx">index</span><span class="p">]</span> <span class="k">else</span> <span class="kc">false</span></pre></div> </td> </tr> <tr id="section-48"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-48">#</a> </div> <h2>Utility Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-49"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-49">#</a> </div> <p>Does a list include a value?</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">include: </span><span class="p">(</span><span class="nx">list</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">list</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="o">&gt;=</span> <span class="mi">0</span></pre></div> </td> </tr> <tr id="section-50"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-50">#</a> </div> <p>Peek at the beginning of a given string to see if it matches a sequence.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">starts: </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">literal</span><span class="p">,</span> <span class="nx">start</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">string</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="p">(</span><span class="nx">start</span> <span class="o">or</span> <span class="mi">0</span><span class="p">)</span> <span class="o">+</span> <span class="nx">literal</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="o">is</span> <span class="nx">literal</span></pre></div> </td> </tr> <tr id="section-51"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-51">#</a> </div> <p>Trim out all falsy values from an array.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">compact: </span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nx">item</span> <span class="k">for</span> <span class="nx">item</span> <span class="k">in</span> <span class="nx">array</span> <span class="k">when</span> <span class="nx">item</span></pre></div> </td> </tr> <tr id="section-52"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-52">#</a> </div> <p>Count the number of occurences of a character in a string.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">count: </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">letter</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">if</span> <span class="nx">m</span> <span class="k">then</span> <span class="nx">m</span><span class="p">[</span><span class="nx">index</span><span class="p">]</span> <span class="k">else</span> <span class="kc">false</span></pre></div> </td> </tr> <tr id="section-49"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-49">#</a> </div> <h2>Utility Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-50"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-50">#</a> </div> <p>Does a list include a value?</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">include: </span><span class="p">(</span><span class="nx">list</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">list</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="o">&gt;=</span> <span class="mi">0</span></pre></div> </td> </tr> <tr id="section-51"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-51">#</a> </div> <p>Peek at the beginning of a given string to see if it matches a sequence.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">starts: </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">literal</span><span class="p">,</span> <span class="nx">start</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">string</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="p">(</span><span class="nx">start</span> <span class="o">or</span> <span class="mi">0</span><span class="p">)</span> <span class="o">+</span> <span class="nx">literal</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="o">is</span> <span class="nx">literal</span></pre></div> </td> </tr> <tr id="section-52"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-52">#</a> </div> <p>Trim out all falsy values from an array.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">compact: </span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nx">item</span> <span class="k">for</span> <span class="nx">item</span> <span class="k">in</span> <span class="nx">array</span> <span class="k">when</span> <span class="nx">item</span></pre></div> </td> </tr> <tr id="section-53"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-53">#</a> </div> <p>Count the number of occurences of a character in a string.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">count: </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">letter</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">num: </span><span class="mi">0</span>
<span class="nv">pos: </span><span class="nx">string</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">letter</span><span class="p">)</span>
<span class="k">while</span> <span class="nx">pos</span> <span class="o">isnt</span> <span class="o">-</span><span class="mi">1</span>