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22 lines
498 B
Haskell
22 lines
498 B
Haskell
module Match where
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import AbsSrc
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import AbsTgt
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import Env
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import STM
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match :: [Case] -> Exp -> STM Env Exp
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match cs v = checks $ map (tryMatch v) cs
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---- return substitution
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tryMatch :: Exp -> Case -> STM Env Exp
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tryMatch e (Cas p v) = if fit (e, p) then return v else raise "no fit" where
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fit (exp,patt) = case (exp,patt) of
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(ECst c es, PCon d ps) ->
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c == d &&
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length es == length ps &&
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all fit (zip es ps)
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(_,PVar _) -> True ---- not is exp contains variables
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