Agda-2.3.2.1: A dependently typed functional programming language and proof assistant

Safe HaskellNone

Agda.Compiler.Epic.Erasure

Description

Some arguments to functions (types in particular) will not be used in the body. Wouldn't it be useful if these wasn't passed around at all? Fear not, we here perform some analysis and try to remove as many of these occurences as possible.

We employ the worker/wrapper transform, so if f x1 .. xn = e and we notice that some is not needed we create: f' xj .. xk = e [xi := unit] and f x1 .. xn = f' xj .. xk. i.e we erase them in f' and replace by unit, and the original f function calls the new f'. The idea is that f should be inlined and then peace on earth.

Synopsis

Documentation

erasure :: [Fun] -> Compile TCM [Fun]Source

Try to find as many unused variables as possible

initiate :: Fun -> Erasure (Compile TCM) ()Source

Initiate a function's relevancies

relevant :: (Functor m, Monad m) => Var -> Expr -> Erasure m RelevanceSource

Calculate if a variable is relevant in an expression

step :: Integer -> Erasure (Compile TCM) (Map Var [Relevance])Source

Try to find a fixpoint for all the functions relevance.

diff :: (Ord k, Eq a) => Map k a -> Map k a -> [(k, (a, a))]Source