git.iko.soy/rowtype-yoga/purescript-native
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rowtype-yoga/purescript-native/src/Language/PureScript/Scope.hs
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1-----------------------------------------------------------------------------
2--
3-- Module : Language.PureScript.Scope
4-- Copyright : (c) Phil Freeman 2013
5-- License : MIT
6--
7-- Maintainer : Phil Freeman <paf31@cantab.net>
8-- Stability : experimental
9-- Portability :
10--
11-- |
12-- Utility functions for working with names in scope
13--
14-----------------------------------------------------------------------------
16module Language.PureScript.Scope (
17 usedNames,
18 unusedNames
19) where
21import Data.Data
22import Data.List ((\\), nub)
23import Data.Generics (extQ, mkQ, everything)
25import Language.PureScript.Values
26import Language.PureScript.Names
27import Language.PureScript.CodeGen.JS.AST
29-- |
30-- Gather all used names appearing inside a value
31--
32usedNames :: (Data d) => d -> [Ident]
33usedNames val = nub $ everything (++) (mkQ [] namesV `extQ` namesB `extQ` namesJS) val
34 where
35 namesV :: Value -> [Ident]
36 namesV (Abs (Left arg) _) = [arg]
37 namesV (Var (Qualified Nothing name)) = [name]
38 namesV _ = []
39 namesB :: Binder -> [Ident]
40 namesB (VarBinder name) = [name]
41 namesB _ = []
42 namesJS :: JS -> [Ident]
43 namesJS (JSVar name) = [Ident name]
44 namesJS (JSFunction (Just name) args _) = (Ident name) : (Ident `map` args)
45 namesJS (JSFunction Nothing args _) = (Ident `map` args)
46 namesJS (JSVariableIntroduction name _) = [Ident name]
47 namesJS (JSFor name _ _ _) = [Ident name]
48 namesJS _ = []
50-- |
51-- Generate a set of names which are unused inside a value, of the form @_{n}@ for an integer @n@
52--
53unusedNames :: (Data d) => d -> [Ident]
54unusedNames val =
55 let
56 allNames = usedNames val
57 varNames = map (Ident . ('_' :) . show) ([1..] :: [Int])
58 in
59 varNames \\ allNames