CurryInfo: rw-data-generator-2.0.0 / RW.Build.consToPolyPattern

 
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) 

 argument 1

 deterministic operation

 
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' _ _ _

 {CCons}

 referentially transparent operation

 no fixity defined

 {({CCons}) |-> {CPComb}}

 consToPolyPattern

 no precedence defined

 {CPComb}

 AbstractCurry.Types.CConsDecl -> AbstractCurry.Types.CPattern

 operation might suspend on free variables

 yes

 possibly non-reducible on same data term