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definition:
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consToPolyPattern :: CConsDecl -> CPattern
consToPolyPattern (CCons name _ tes) = CPComb name pats
where
pats = map convert tes
-- Converts a type expression to a pattern such that only type variables are pattern-matched (bound to a variable)
convert te = case te of
CTVar (i, n) -> CPVar (i, n ++ "'")
_ -> anonPattern
-- Replaces all recurrences of type variables in a list of type expressions with wildcards
anonDuplicates (x:xs) | x == anonPattern = x : anonDuplicates xs
| otherwise = x : anonDuplicates (substitute x anonPattern xs)
anonDuplicates [] = []
-- Replaces all occurrences of a type variable pattern with a wildcard pattern
substitute v1 v2 = map (\x -> if x == v1 then v2 else x)
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demand:
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argument 1
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deterministic:
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deterministic operation
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documentation:
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Pattern-matches the first occurrence of every type variable in a given type expression.
For a specific constructor of a type definition
data T t1 ... tn = ... | C e1 ... em | ...
this function generates a pattern
C p1 ... pm
where pi (1 <= i <= m) is...
- a variable ei' if ei the first occurence of a polymorphic type variable t1 ... tn in the constructor
- a wildcard _ otherwise
Example:
data T a = C a String a [a]
consToPolyPattern C -> C a' _ _ _
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failfree:
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{CCons}
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indeterministic:
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referentially transparent operation
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infix:
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no fixity defined
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iotype:
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{({CCons}) |-> {CPComb}}
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name:
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consToPolyPattern
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precedence:
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no precedence defined
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result-values:
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{CPComb}
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signature:
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AbstractCurry.Types.CConsDecl -> AbstractCurry.Types.CPattern
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solution-complete:
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operation might suspend on free variables
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terminating:
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yes
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totally-defined:
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possibly non-reducible on same data term
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