DDC.Core.Transform.Rewrite.Match

Create substitution to make (subst template) == target

Substitutions

type SubstInfo a n = (Map n (Exp a n), Map n (Type n))

Value and type substition.

emptySubstInfo :: SubstInfo a n

An empty substition info.

Matching

match

Arguments

:: (Show a, Show n, Ord n)

=> SubstInfo a n

Current substitution

-> Set n

Variables we're interested in

-> Exp a n

Template expression.

-> Exp a n

Target expression.

-> Maybe (SubstInfo a n)

Create substitution to make (subst template) == target Does not handle higher-order templates (ie ones with binders)

 match emptySubstInfo (Set.fromList [r1, r2, s])
   (stream [r1]  (unstream [r2]  s))
   (stream [R0] (someStream 23))

=> { r1 |-> R0#, r2 |-> R1, s |-> someStream 23 }