This module contains a compiler pass that qualifies the names of all top-level declarations of the converted module with the name of that module.

Example

Consider the following module.

module Data.Tree where

data Tree a = Leaf a | Branch (Tree a) (Tree a)

mapTree :: (a -> b) -> Tree a -> Tree b
mapTree f t = case t of
  Leaf x     -> Leaf (f x)
  Branch l r -> Branch (mapTree f l) (mapTree f r)

After this pass the declarations of Tree and mapTree as well as the type signature for mapTree and the constructors Leaf and Branch are qualified.

module Data.Tree where

data Data.Tree.Tree a
  = Data.Tree.Leaf a
  | Data.Tree.Branch (Tree a) (Tree a)

Data.Tree.mapTree :: (a -> b) -> Tree a -> Tree b
Data.Tree.mapTree f t = case t of
  Leaf x     -> Leaf (f x)
  Branch l r -> Branch (mapTree f l) (mapTree f r)

However, references to Tree, Leaf, Branch and mapTree in the fields of the constructor declarations and on the right-hand side of the function's type signature and declaration remain unqualified. Also (type) arguments and local variable are not affected.

Specification

Precondition

There are no special requirements.

Translation

In a module M all declarations, type signatures and pragmas of the forms

• type T α₁ … αₘ = τ

• data D α₁ … αₘ = C₁ τ₍₁,₁₎ … τ₍₁,ₖ₁₎ | … | Cₙ τ₍ₙ,₁₎ … τ₍ₙ,ₖₙ₎

• f₁, …, fₙ :: τ

• f x₁ … xₙ = e

• {-# FreeC f DECREASES ON x #-}

are translated to

• type M.T α₁ … αₘ = τ

• data M.D α₁ … αₘ = M.C₁ τ₍₁,₁₎ … τ₍₁,ₖ₁₎ | … | M.Cₙ τ₍ₙ,₁₎ … τ₍ₙ,ₖₙ₎

• M.f₁, …, M.fₙ :: τ

• M.f x₁ … xₙ = e

• {-# FreeC M.f DECREASES ON x #-}

If an identifier is qualified already, it keeps its original qualifier.

Postcondition

All DeclIdents in the module contain qualified identifiers (i.e., Quals).