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<title>src/full/Agda/Utils/VarSet.hs</title>
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<pre><a name="line-1"></a>
<a name="line-2"></a><span class='hs-comment'>-- | Var field implementation of sets of (small) natural numbers.</span>
<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'>Utils</span><span class='hs-varop'>.</span><span class='hs-conid'>VarSet</span>
<a name="line-4"></a> <span class='hs-layout'>(</span> <span class='hs-conid'>VarSet</span>
<a name="line-5"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>union</span><span class='hs-layout'>,</span> <span class='hs-varid'>unions</span><span class='hs-layout'>,</span> <span class='hs-varid'>member</span><span class='hs-layout'>,</span> <span class='hs-varid'>empty</span><span class='hs-layout'>,</span> <span class='hs-varid'>delete</span><span class='hs-layout'>,</span> <span class='hs-varid'>singleton</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromList</span><span class='hs-layout'>,</span> <span class='hs-varid'>toList</span><span class='hs-layout'>,</span> <span class='hs-varid'>isSubsetOf</span>
<a name="line-6"></a> <span class='hs-layout'>,</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'>VarSet</span><span class='hs-varop'>.</span><span class='hs-varid'>subtract</span>
<a name="line-7"></a> <span class='hs-layout'>)</span>
<a name="line-8"></a> <span class='hs-keyword'>where</span>
<a name="line-9"></a>
<a name="line-10"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>IntSet</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>Set</span>
<a name="line-11"></a>
<a name="line-12"></a><a name="VarSet"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>VarSet</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Set</span><span class='hs-varop'>.</span><span class='hs-conid'>IntSet</span>
<a name="line-13"></a>
<a name="line-14"></a><a name="subtract"></a><span class='hs-definition'>subtract</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>VarSet</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>VarSet</span>
<a name="line-15"></a><span class='hs-definition'>subtract</span> <span class='hs-varid'>n</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Set</span><span class='hs-varop'>.</span><span class='hs-varid'>map</span> <span class='hs-layout'>(</span><span class='hs-conid'>Prelude</span><span class='hs-varop'>.</span><span class='hs-varid'>subtract</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='hs-comment'>{-
<a name="line-18"></a>import Data.Bits
<a name="line-19"></a>
<a name="line-20"></a>type VarSet = Integer
<a name="line-21"></a>type Var = Integer
<a name="line-22"></a>
<a name="line-23"></a>union :: VarSet -> VarSet -> VarSet
<a name="line-24"></a>union = (.|.)
<a name="line-25"></a>
<a name="line-26"></a>member :: Var -> VarSet -> Bool
<a name="line-27"></a>member b s = testVar s (fromIntegral b)
<a name="line-28"></a>
<a name="line-29"></a>empty :: VarSet
<a name="line-30"></a>empty = 0
<a name="line-31"></a>
<a name="line-32"></a>delete :: Var -> VarSet -> VarSet
<a name="line-33"></a>delete b s = clearVar s (fromIntegral b)
<a name="line-34"></a>
<a name="line-35"></a>singleton :: Var -> VarSet
<a name="line-36"></a>singleton = bit
<a name="line-37"></a>
<a name="line-38"></a>subtract :: Int -> VarSet -> VarSet
<a name="line-39"></a>subtract n s = shiftR s n
<a name="line-40"></a>
<a name="line-41"></a>fromList :: [Var] -> VarSet
<a name="line-42"></a>fromList = foldr (union . singleton . fromIntegral) empty
<a name="line-43"></a>
<a name="line-44"></a>isSubsetOf :: VarSet -> VarSet -> Bool
<a name="line-45"></a>isSubsetOf s1 s2 = 0 == (s1 .&. complement s2)
<a name="line-46"></a>
<a name="line-47"></a>toList :: VarSet -> [Var]
<a name="line-48"></a>toList s = loop 0 s
<a name="line-49"></a> where
<a name="line-50"></a> loop i 0 = []
<a name="line-51"></a> loop i n
<a name="line-52"></a> | testVar n 0 = fromIntegral i : (loop $! i + 1) (shiftR n 1)
<a name="line-53"></a> | otherwise = (loop $! i + 1) (shiftR n 1)
<a name="line-54"></a>-}</span>
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