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<title>Language/Haskell/HsColour/Anchors.hs</title>
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<pre><a name="line-1"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Language</span><span class='hs-varop'>.</span><span class='hs-conid'>Haskell</span><span class='hs-varop'>.</span><span class='hs-conid'>HsColour</span><span class='hs-varop'>.</span><span class='hs-conid'>Anchors</span>
<a name="line-2"></a> <span class='hs-layout'>(</span> <span class='hs-varid'>insertAnchors</span>
<a name="line-3"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-4"></a>
<a name="line-5"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Language</span><span class='hs-varop'>.</span><span class='hs-conid'>Haskell</span><span class='hs-varop'>.</span><span class='hs-conid'>HsColour</span><span class='hs-varop'>.</span><span class='hs-conid'>Classify</span>
<a name="line-6"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Language</span><span class='hs-varop'>.</span><span class='hs-conid'>Haskell</span><span class='hs-varop'>.</span><span class='hs-conid'>HsColour</span><span class='hs-varop'>.</span><span class='hs-conid'>General</span>
<a name="line-7"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>List</span>
<a name="line-8"></a>
<a name="line-9"></a><span class='hs-comment'>-- This is an attempt to find the first defining occurrence of an</span>
<a name="line-10"></a><span class='hs-comment'>-- identifier (function, datatype, class) in a Haskell source file.</span>
<a name="line-11"></a><span class='hs-comment'>-- Rather than parse the module properly, we try to get by with just</span>
<a name="line-12"></a><span class='hs-comment'>-- a finite state automaton. Keeping a record of identifiers we</span>
<a name="line-13"></a><span class='hs-comment'>-- have already seen, we look at the beginning of every line to see</span>
<a name="line-14"></a><span class='hs-comment'>-- if it starts with the right tokens to introduce a defn. If so,</span>
<a name="line-15"></a><span class='hs-comment'>-- we look a little bit further until we can be certain. Then plonk</span>
<a name="line-16"></a><span class='hs-comment'>-- (or not) an anchor at the beginning of the line.</span>
<a name="line-17"></a>
<a name="line-18"></a><a name="Anchor"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Anchor</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>String</span>
<a name="line-19"></a>
<a name="line-20"></a><a name="insertAnchors"></a><span class='hs-comment'>-- | 'insertAnchors' places an anchor marker in the token stream before the</span>
<a name="line-21"></a><span class='hs-comment'>-- first defining occurrence of any identifier. Here, /before/ means</span>
<a name="line-22"></a><span class='hs-comment'>-- immediately preceding its type signature, or preceding a (haddock)</span>
<a name="line-23"></a><span class='hs-comment'>-- comment that comes immediately before the type signature, or failing</span>
<a name="line-24"></a><span class='hs-comment'>-- either of those, before the first equation.</span>
<a name="line-25"></a><span class='hs-definition'>insertAnchors</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>TokenType</span><span class='hs-layout'>,</span><span class='hs-conid'>String</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Either</span> <span class='hs-conid'>Anchor</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokenType</span><span class='hs-layout'>,</span><span class='hs-conid'>String</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-26"></a><span class='hs-definition'>insertAnchors</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>anchor</span> <span class='hs-varid'>emptyST</span>
<a name="line-27"></a>
<a name="line-28"></a><a name="anchor"></a><span class='hs-comment'>-- looks at first token in the left-most position of each line</span>
<a name="line-29"></a><span class='hs-comment'>-- precondition: have just seen a newline token.</span>
<a name="line-30"></a><span class='hs-definition'>anchor</span> <span class='hs-varid'>st</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>s</span> <span class='hs-keyword'>of</span>
<a name="line-31"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>emit</span> <span class='hs-varid'>st</span> <span class='hs-varid'>s</span>
<a name="line-32"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Left</span> <span class='hs-varid'>v</span><span class='hs-conop'>:</span> <span class='hs-varid'>emit</span> <span class='hs-layout'>(</span><span class='hs-varid'>insertST</span> <span class='hs-varid'>v</span> <span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>
<a name="line-33"></a>
<a name="line-34"></a><a name="emit"></a><span class='hs-comment'>-- emit passes stuff through until the next newline has been encountered,</span>
<a name="line-35"></a><span class='hs-comment'>-- then jumps back into the anchor function</span>
<a name="line-36"></a><span class='hs-comment'>-- pre-condition: newlines are explicitly single tokens</span>
<a name="line-37"></a><span class='hs-definition'>emit</span> <span class='hs-varid'>st</span> <span class='hs-layout'>(</span><span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Space</span><span class='hs-layout'>,</span><span class='hs-str'>"\n"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varid'>t</span><span class='hs-conop'>:</span> <span class='hs-varid'>anchor</span> <span class='hs-varid'>st</span> <span class='hs-varid'>stream</span>
<a name="line-38"></a><span class='hs-definition'>emit</span> <span class='hs-varid'>st</span> <span class='hs-layout'>(</span><span class='hs-varid'>t</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varid'>t</span><span class='hs-conop'>:</span> <span class='hs-varid'>emit</span> <span class='hs-varid'>st</span> <span class='hs-varid'>stream</span>
<a name="line-39"></a><span class='hs-definition'>emit</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-40"></a>
<a name="line-41"></a><a name="identifier"></a><span class='hs-comment'>-- Given that we are at the beginning of a line, determine whether there</span>
<a name="line-42"></a><span class='hs-comment'>-- is an identifier defined here, and if so, return it.</span>
<a name="line-43"></a><span class='hs-comment'>-- precondition: have just seen a newline token.</span>
<a name="line-44"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>kind</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>kind</span><span class='hs-varop'>`elem`</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>Varid</span><span class='hs-layout'>,</span><span class='hs-conid'>Definition</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span>
<a name="line-45"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>stream</span> <span class='hs-keyword'>of</span>
<a name="line-46"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Varop</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>v</span><span class='hs-varop'>`inST`</span><span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>fix</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-47"></a> <span class='hs-varid'>notVarop</span> <span class='hs-comment'>-- | typesig stream -> Nothing -- not a defn</span>
<a name="line-48"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>v</span> <span class='hs-varop'>`inST`</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span> <span class='hs-comment'>-- already defined</span>
<a name="line-49"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-50"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>"("</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-51"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>stream</span> <span class='hs-keyword'>of</span>
<a name="line-52"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Varop</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>")"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span>
<a name="line-53"></a> <span class='hs-comment'>-- | typesig stream -> Nothing</span>
<a name="line-54"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>v</span> <span class='hs-varop'>`inST`</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span>
<a name="line-55"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>fix</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-56"></a> <span class='hs-varid'>notVarop</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>skip</span> <span class='hs-layout'>(</span><span class='hs-varid'>munchParens</span> <span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-57"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Varop</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>v</span><span class='hs-varop'>`inST`</span><span class='hs-varid'>st</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>fix</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-58"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span>
<a name="line-59"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyword</span><span class='hs-layout'>,</span><span class='hs-str'>"foreign"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span> <span class='hs-comment'>-- not yet implemented</span>
<a name="line-60"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyword</span><span class='hs-layout'>,</span><span class='hs-str'>"data"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getConid</span> <span class='hs-varid'>stream</span>
<a name="line-61"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyword</span><span class='hs-layout'>,</span><span class='hs-str'>"newtype"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getConid</span> <span class='hs-varid'>stream</span>
<a name="line-62"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyword</span><span class='hs-layout'>,</span><span class='hs-str'>"type"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getConid</span> <span class='hs-varid'>stream</span>
<a name="line-63"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyword</span><span class='hs-layout'>,</span><span class='hs-str'>"class"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getConid</span> <span class='hs-varid'>stream</span>
<a name="line-64"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Comment</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-layout'>(</span><span class='hs-conid'>Space</span><span class='hs-layout'>,</span><span class='hs-str'>"\n"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>stream</span>
<a name="line-65"></a><span class='hs-definition'>identifier</span> <span class='hs-varid'>st</span> <span class='hs-varid'>stream</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-66"></a>
<a name="line-67"></a><a name="typesig"></a><span class='hs-comment'>-- Is this really a type signature? (no longer used)</span>
<a name="line-68"></a><span class='hs-definition'>typesig</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>TokenType</span><span class='hs-layout'>,</span><span class='hs-conid'>String</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-69"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"::"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-70"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Varid</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>typesig</span> <span class='hs-varid'>stream</span>
<a name="line-71"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>"("</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-layout'>(</span><span class='hs-conid'>Varop</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>")"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>typesig</span> <span class='hs-varid'>stream</span>
<a name="line-72"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>","</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>typesig</span> <span class='hs-varid'>stream</span>
<a name="line-73"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Space</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>typesig</span> <span class='hs-varid'>stream</span>
<a name="line-74"></a><span class='hs-definition'>typesig</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Comment</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>typesig</span> <span class='hs-varid'>stream</span>
<a name="line-75"></a><span class='hs-definition'>typesig</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-76"></a>
<a name="line-77"></a><a name="munchParens"></a><span class='hs-comment'>-- throw away everything from opening paren to matching close</span>
<a name="line-78"></a><span class='hs-definition'>munchParens</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>munch</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-keyglyph'>::</span><span class='hs-conid'>Int</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- already seen open paren</span>
<a name="line-79"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>munch</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>")"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>rest</span>
<a name="line-80"></a> <span class='hs-varid'>munch</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>")"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>munch</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>rest</span>
<a name="line-81"></a> <span class='hs-varid'>munch</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>"("</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>munch</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>rest</span>
<a name="line-82"></a> <span class='hs-varid'>munch</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>munch</span> <span class='hs-varid'>n</span> <span class='hs-varid'>rest</span>
<a name="line-83"></a> <span class='hs-varid'>munch</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <span class='hs-comment'>-- source is ill-formed</span>
<a name="line-84"></a>
<a name="line-85"></a><a name="fix"></a><span class='hs-comment'>-- ensure anchor name is correct for a Varop</span>
<a name="line-86"></a><span class='hs-definition'>fix</span> <span class='hs-layout'>(</span><span class='hs-chr'>'`'</span><span class='hs-conop'>:</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropLast</span> <span class='hs-chr'>'`'</span> <span class='hs-varid'>v</span>
<a name="line-87"></a><span class='hs-definition'>fix</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v</span>
<a name="line-88"></a>
<a name="line-89"></a><a name="skip"></a><span class='hs-comment'>-- look past whitespace and comments to next "real" token</span>
<a name="line-90"></a><span class='hs-definition'>skip</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Space</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>stream</span>
<a name="line-91"></a><span class='hs-definition'>skip</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Comment</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>stream</span>
<a name="line-92"></a><span class='hs-definition'>skip</span> <span class='hs-varid'>stream</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>stream</span>
<a name="line-93"></a>
<a name="line-94"></a><a name="getConid"></a><span class='hs-comment'>-- skip possible context up to and including "=>", returning next Conid token</span>
<a name="line-95"></a><span class='hs-comment'>-- (this function is highly partial - relies on source being parse-correct)</span>
<a name="line-96"></a><span class='hs-definition'>getConid</span> <span class='hs-varid'>stream</span> <span class='hs-keyglyph'>=</span>
<a name="line-97"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>stream</span> <span class='hs-keyword'>of</span>
<a name="line-98"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Conid</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>context</span> <span class='hs-varid'>rest</span> <span class='hs-keyword'>of</span>
<a name="line-99"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"="</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>c</span>
<a name="line-100"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"=>"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>more</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-101"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>more</span> <span class='hs-keyword'>of</span>
<a name="line-102"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Conid</span><span class='hs-layout'>,</span><span class='hs-varid'>c'</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>c'</span>
<a name="line-103"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>debug</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-str'>"Conid "</span><span class='hs-varop'>++</span><span class='hs-varid'>c</span><span class='hs-varop'>++</span><span class='hs-str'>" =>"</span><span class='hs-layout'>)</span>
<a name="line-104"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>debug</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-str'>"Conid "</span><span class='hs-varop'>++</span><span class='hs-varid'>c</span><span class='hs-varop'>++</span><span class='hs-str'>" no = or =>"</span><span class='hs-layout'>)</span>
<a name="line-105"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Layout</span><span class='hs-layout'>,</span><span class='hs-str'>"("</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>context</span> <span class='hs-varid'>rest</span> <span class='hs-keyword'>of</span>
<a name="line-106"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"=>"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>more</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-107"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>skip</span> <span class='hs-varid'>more</span> <span class='hs-keyword'>of</span>
<a name="line-108"></a> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Conid</span><span class='hs-layout'>,</span><span class='hs-varid'>c'</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>c'</span>
<a name="line-109"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>debug</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-str'>"(...) =>"</span><span class='hs-layout'>)</span>
<a name="line-110"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>debug</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-str'>"(...) no =>"</span><span class='hs-layout'>)</span>
<a name="line-111"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>debug</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-str'>"no Conid or (...)"</span><span class='hs-layout'>)</span>
<a name="line-112"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>debug</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-113"></a> <span class='hs-comment'>-- debug (s:t) c = error ("HsColour: getConid failed: "++show s</span>
<a name="line-114"></a> <span class='hs-comment'>-- ++"\n in the context of: "++c)</span>
<a name="line-115"></a>
<a name="line-116"></a><a name="context"></a><span class='hs-comment'>-- jump past possible class context</span>
<a name="line-117"></a><span class='hs-definition'>context</span> <span class='hs-varid'>stream</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"="</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>stream</span>
<a name="line-118"></a><span class='hs-definition'>context</span> <span class='hs-varid'>stream</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Keyglyph</span><span class='hs-layout'>,</span><span class='hs-str'>"=>"</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>stream</span>
<a name="line-119"></a><span class='hs-definition'>context</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>stream</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>context</span> <span class='hs-varid'>stream</span>
<a name="line-120"></a><span class='hs-definition'>context</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-121"></a>
<a name="line-122"></a><a name="ST"></a><span class='hs-comment'>-- simple implementation of a string lookup table.</span>
<a name="line-123"></a><a name="ST"></a><span class='hs-comment'>-- replace this with something more sophisticated if needed.</span>
<a name="line-124"></a><a name="ST"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>ST</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span>
<a name="line-125"></a>
<a name="line-126"></a><a name="emptyST"></a><span class='hs-definition'>emptyST</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ST</span>
<a name="line-127"></a><span class='hs-definition'>emptyST</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-128"></a>
<a name="line-129"></a><a name="insertST"></a><span class='hs-definition'>insertST</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ST</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ST</span>
<a name="line-130"></a><span class='hs-definition'>insertST</span> <span class='hs-varid'>k</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>insert</span> <span class='hs-varid'>k</span> <span class='hs-varid'>st</span>
<a name="line-131"></a>
<a name="line-132"></a><a name="inST"></a><span class='hs-definition'>inST</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ST</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-133"></a><span class='hs-definition'>inST</span> <span class='hs-varid'>k</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>st</span>
</pre></body>
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