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<title>src/full/Agda/TypeChecking/Eliminators.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE CPP #-}</span>
<a name="line-2"></a>
<a name="line-3"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>TypeChecking</span><span class='hs-varop'>.</span><span class='hs-conid'>Eliminators</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'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span>
<a name="line-6"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span>
<a name="line-7"></a>
<a name="line-8"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>Syntax</span><span class='hs-varop'>.</span><span class='hs-conid'>Common</span>
<a name="line-9"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>Syntax</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span>
<a name="line-10"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>TypeChecking</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span>
<a name="line-11"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>TypeChecking</span><span class='hs-varop'>.</span><span class='hs-conid'>Substitute</span>
<a name="line-12"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>Utils</span><span class='hs-varop'>.</span><span class='hs-conid'>Impossible</span>
<a name="line-13"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>TypeChecking</span><span class='hs-varop'>.</span><span class='hs-conid'>Reduce</span>
<a name="line-14"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Agda</span><span class='hs-varop'>.</span><span class='hs-conid'>TypeChecking</span><span class='hs-varop'>.</span><span class='hs-conid'>Level</span>
<a name="line-15"></a>
<a name="line-16"></a><span class='hs-cpp'>#include "../undefined.h"</span>
<a name="line-17"></a>
<a name="line-18"></a><a name="ElimView"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>ElimView</span>
<a name="line-19"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>VarElim</span> <span class='hs-conid'>Nat</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Elim</span><span class='hs-keyglyph'>]</span>
<a name="line-20"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>DefElim</span> <span class='hs-conid'>QName</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Elim</span><span class='hs-keyglyph'>]</span>
<a name="line-21"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>ConElim</span> <span class='hs-conid'>QName</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Elim</span><span class='hs-keyglyph'>]</span>
<a name="line-22"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>MetaElim</span> <span class='hs-conid'>MetaId</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Elim</span><span class='hs-keyglyph'>]</span>
<a name="line-23"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>NoElim</span> <span class='hs-conid'>Term</span>
<a name="line-24"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-25"></a>
<a name="line-26"></a><a name="elimView"></a><span class='hs-definition'>elimView</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Term</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>TCM</span> <span class='hs-conid'>ElimView</span>
<a name="line-27"></a><span class='hs-definition'>elimView</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-28"></a> <span class='hs-comment'>-- We can't assume that v has been reduced here in recursive calls,</span>
<a name="line-29"></a> <span class='hs-comment'>-- since reducing a stuck application doesn't necessarily reduces all</span>
<a name="line-30"></a> <span class='hs-comment'>-- the arguments.</span>
<a name="line-31"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>reduce</span> <span class='hs-varid'>v</span>
<a name="line-32"></a> <span class='hs-comment'>-- domi 2012-7-24: Add unLevel to handle neutral levels. The problem is that reduce turns</span>
<a name="line-33"></a> <span class='hs-comment'>-- suc (neutral) into Level (Max [Plus 1 (NeutralLevel neutral)]) which the below pattern</span>
<a name="line-34"></a> <span class='hs-comment'>-- match does not handle.</span>
<a name="line-35"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>unLevel</span> <span class='hs-varid'>v</span>
<a name="line-36"></a> <span class='hs-varid'>reportSLn</span> <span class='hs-str'>"tc.conv.elim"</span> <span class='hs-num'>50</span> <span class='hs-varop'>$</span> <span class='hs-str'>"v = "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>show</span> <span class='hs-varid'>v</span>
<a name="line-37"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ignoreSharing</span> <span class='hs-varid'>v</span> <span class='hs-keyword'>of</span>
<a name="line-38"></a> <span class='hs-conid'>Def</span> <span class='hs-varid'>f</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-39"></a> <span class='hs-varid'>proj</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>isProjection</span> <span class='hs-varid'>f</span>
<a name="line-40"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>proj</span> <span class='hs-keyword'>of</span>
<a name="line-41"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>DefElim</span> <span class='hs-varid'>f</span> <span class='hs-varop'>`app`</span> <span class='hs-varid'>vs</span>
<a name="line-42"></a> <span class='hs-conid'>Just</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-43"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>vs</span> <span class='hs-keyword'>of</span>
<a name="line-44"></a> <span class='hs-varid'>rv</span> <span class='hs-conop'>:</span> <span class='hs-varid'>vs'</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>elim</span> <span class='hs-layout'>(</span><span class='hs-conid'>Proj</span> <span class='hs-varid'>f</span> <span class='hs-conop'>:</span> <span class='hs-varid'>map</span> <span class='hs-conid'>Apply</span> <span class='hs-varid'>vs'</span><span class='hs-layout'>)</span> <span class='hs-varop'><$></span> <span class='hs-varid'>elimView</span> <span class='hs-layout'>(</span><span class='hs-varid'>unArg</span> <span class='hs-varid'>rv</span><span class='hs-layout'>)</span>
<a name="line-45"></a> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>-></span> <span class='hs-sel'>__IMPOSSIBLE__</span>
<a name="line-46"></a> <span class='hs-comment'>-- elimView should only be called from the conversion checker</span>
<a name="line-47"></a> <span class='hs-comment'>-- with properly saturated applications</span>
<a name="line-48"></a> <span class='hs-conid'>Var</span> <span class='hs-varid'>x</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>VarElim</span> <span class='hs-varid'>x</span> <span class='hs-varop'>`app`</span> <span class='hs-varid'>vs</span>
<a name="line-49"></a> <span class='hs-conid'>Con</span> <span class='hs-varid'>c</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ConElim</span> <span class='hs-varid'>c</span> <span class='hs-varop'>`app`</span> <span class='hs-varid'>vs</span>
<a name="line-50"></a> <span class='hs-conid'>MetaV</span> <span class='hs-varid'>m</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>MetaElim</span> <span class='hs-varid'>m</span> <span class='hs-varop'>`app`</span> <span class='hs-varid'>vs</span>
<a name="line-51"></a> <span class='hs-conid'>Lam</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-52"></a> <span class='hs-conid'>Lit</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-53"></a> <span class='hs-conid'>Level</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-54"></a> <span class='hs-conid'>Sort</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-55"></a> <span class='hs-conid'>Pi</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-56"></a> <span class='hs-conid'>DontCare</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>noElim</span>
<a name="line-57"></a> <span class='hs-conid'>Shared</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>-></span> <span class='hs-sel'>__IMPOSSIBLE__</span>
<a name="line-58"></a> <span class='hs-keyword'>where</span>
<a name="line-59"></a> <span class='hs-varid'>noElim</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>NoElim</span> <span class='hs-varid'>v</span>
<a name="line-60"></a> <span class='hs-varid'>app</span> <span class='hs-varid'>f</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span> <span class='hs-varid'>map</span> <span class='hs-conid'>Apply</span> <span class='hs-varid'>vs</span>
<a name="line-61"></a> <span class='hs-varid'>elim</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Elim</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ElimView</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ElimView</span>
<a name="line-62"></a> <span class='hs-varid'>elim</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>NoElim</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-sel'>__IMPOSSIBLE__</span>
<a name="line-63"></a> <span class='hs-varid'>elim</span> <span class='hs-varid'>es2</span> <span class='hs-layout'>(</span><span class='hs-conid'>VarElim</span> <span class='hs-varid'>x</span> <span class='hs-varid'>es1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>VarElim</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>es1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>es2</span><span class='hs-layout'>)</span>
<a name="line-64"></a> <span class='hs-varid'>elim</span> <span class='hs-varid'>es2</span> <span class='hs-layout'>(</span><span class='hs-conid'>DefElim</span> <span class='hs-varid'>x</span> <span class='hs-varid'>es1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DefElim</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>es1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>es2</span><span class='hs-layout'>)</span>
<a name="line-65"></a> <span class='hs-varid'>elim</span> <span class='hs-varid'>es2</span> <span class='hs-layout'>(</span><span class='hs-conid'>ConElim</span> <span class='hs-varid'>x</span> <span class='hs-varid'>es1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ConElim</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>es1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>es2</span><span class='hs-layout'>)</span>
<a name="line-66"></a> <span class='hs-varid'>elim</span> <span class='hs-varid'>es2</span> <span class='hs-layout'>(</span><span class='hs-conid'>MetaElim</span> <span class='hs-varid'>x</span> <span class='hs-varid'>es1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MetaElim</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>es1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>es2</span><span class='hs-layout'>)</span>
<a name="line-67"></a>
<a name="line-68"></a><span class='hs-comment'>{- UNUSED
<a name="line-69"></a>-- | Only used when producing error messages.
<a name="line-70"></a>unElimView :: ElimView -> Term
<a name="line-71"></a>unElimView v = case v of
<a name="line-72"></a> VarElim x es -> unElim (Var x []) es
<a name="line-73"></a> DefElim x es -> unElim (Def x []) es
<a name="line-74"></a> ConElim x es -> unElim (Con x []) es
<a name="line-75"></a> MetaElim x es -> unElim (MetaV x []) es
<a name="line-76"></a> NoElim v -> v
<a name="line-77"></a>
<a name="line-78"></a>unElim :: Term -> [Elim] -> Term
<a name="line-79"></a>unElim v [] = v
<a name="line-80"></a>unElim v (Apply u : es) = unElim (v `apply` [u]) es
<a name="line-81"></a>unElim v (Proj f : es) = unElim (Def f [Arg NotHidden Relevant v]) es
<a name="line-82"></a>-}</span>
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