git.iko.soy/rowtype-yoga/purescript-native
on 75450ea help sign in
rowtype-yoga/purescript-native/src/Language/PureScript/TypeClassDictionaries.hs
73 lines 2.1 kB history raw
1-----------------------------------------------------------------------------
2--
3-- Module : Language.PureScript.TypeClassDictionaries
4-- Copyright : (c) 2014 Phil Freeman
5-- License : MIT
6--
7-- Maintainer : Phil Freeman <paf31@cantab.net>
8-- Stability : experimental
9-- Portability :
10--
11-- |
12--
13-----------------------------------------------------------------------------
15{-# LANGUAGE DeriveDataTypeable #-}
17module Language.PureScript.TypeClassDictionaries where
19import Data.Data
21import Language.PureScript.Names
22import Language.PureScript.Types
24-- |
25-- Data representing a type class dictionary which is in scope
26--
27data TypeClassDictionaryInScope
28 = TypeClassDictionaryInScope {
29 -- |
30 -- The identifier with which the dictionary can be accessed at runtime
31 --
32 tcdName :: Qualified Ident
33 -- |
34 -- The name of the type class to which this type class instance applies
35 --
36 , tcdClassName :: Qualified ProperName
37 -- |
38 -- The types to which this type class instance applies
39 --
40 , tcdInstanceTypes :: [Type]
41 -- |
42 -- Type class dependencies which must be satisfied to construct this dictionary
43 --
44 , tcdDependencies :: Maybe [(Qualified ProperName, [Type])]
45 -- |
46 -- The type of this dictionary
47 --
48 , tcdType :: TypeClassDictionaryType
49 -- |
50 -- Is this instance exported by its module?
51 --
52 , tcdExported :: Bool
53 } deriving (Show, Data, Typeable)
55-- |
56-- The type of a type class dictionary
57--
58data TypeClassDictionaryType
59 -- |
60 -- A regular type class dictionary
61 --
62 = TCDRegular
63 -- |
64 -- A type class dictionary which is an alias for an imported dictionary from another module
65 --
66 | TCDAlias (Qualified Ident) deriving (Show, Eq, Data, Typeable)
68-- |
69-- Find the original dictionary which a type class dictionary in scope refers to
70--
71canonicalizeDictionary :: TypeClassDictionaryInScope -> Qualified Ident
72canonicalizeDictionary (TypeClassDictionaryInScope { tcdType = TCDRegular, tcdName = nm }) = nm
73canonicalizeDictionary (TypeClassDictionaryInScope { tcdType = TCDAlias nm }) = nm