Language.Syntactic.Interpretation.Equality

Documentation

class Equality expr where

Equality for expressions

Minimal complete definition

Nothing

Methods

equal :: expr a -> expr b -> Bool

Equality for expressions

Comparing expressions of different types is often needed when dealing with expressions with existentially quantified sub-terms.

exprHash :: expr a -> Hash

Computes a Hash for an expression. Expressions that are equal according to equal must result in the same hash:

equal a b  ==>  exprHash a == exprHash b

Instances

Equality Semantics

Equality Empty

Equality Condition

Equality Construct

Equality Identity

Equality Literal

Equality Tuple

Equality Select

Equality Let

Equality Lambda

equal does strict identifier comparison; i.e. no alpha equivalence.

exprHash assigns the same hash to all Lambda bindings. This is a valid over-approximation that enables the following property:

alphaEq a b  ==>  exprHash a == exprHash b

Equality Variable

equal does strict identifier comparison; i.e. no alpha equivalence.

exprHash assigns the same hash to all variables. This is a valid over-approximation that enables the following property:

alphaEq a b  ==>  exprHash a == exprHash b

Equality dom => Equality (AST dom)

Monad m => Equality (MONAD m)

(Equality expr1, Equality expr2) => Equality ((:+:) expr1 expr2)

Equality dom => Equality ((:||) dom pred)

Equality dom => Equality ((:|) dom pred)

Equality expr => Equality (Decor info expr)

Equality dom => Equality (SubConstr1 c dom p)

Equality dom => Equality (SubConstr2 c dom pa pb)

equalDefault :: Semantic expr => expr a -> expr b -> Bool

Default implementation of equal

exprHashDefault :: Semantic expr => expr a -> Hash

Default implementation of exprHash