git.iko.soy/elk
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elk/src/Generate/Substitute.hs
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1{-# OPTIONS_GHC -Wall #-}
2module Generate.Substitute (subst) where
4import Control.Arrow (second, (***))
6import AST.Expression.General (Expr'(..), PortImpl(..))
7import qualified AST.Expression.Canonical as Canonical
8import qualified AST.Pattern as Pattern
9import qualified AST.Variable as V
10import Elm.Utils ((|>))
11import qualified Reporting.Annotation as A
14subst :: String -> Canonical.Expr' -> Canonical.Expr' -> Canonical.Expr'
15subst old new expression =
16 let f (A.A a e) = A.A a (subst old new e) in
17 case expression of
18 Range e1 e2 ->
19 Range (f e1) (f e2)
21 ExplicitList exprs ->
22 ExplicitList (map f exprs)
24 Binop op e1 e2 ->
25 Binop op (f e1) (f e2)
27 Lambda pattern body ->
28 if Pattern.member old pattern
29 then expression
30 else Lambda pattern (f body)
32 App e1 e2 ->
33 App (f e1) (f e2)
35 MultiIf branches ->
36 MultiIf (map (f *** f) branches)
38 Let defs body ->
39 if anyShadow
40 then expression
41 else Let (map substDef defs) (f body)
42 where
43 substDef (Canonical.Definition p e t) =
44 Canonical.Definition p (f e) t
46 anyShadow =
47 map (\(Canonical.Definition p _ _) -> p) defs
48 |> any (Pattern.member old)
50 Var (V.Canonical home x) ->
51 case home of
52 V.Module _ ->
53 expression
55 V.BuiltIn ->
56 expression
58 V.Local ->
59 if x == old then new else expression
61 Case e cases ->
62 Case (f e) (map substCase cases)
63 where
64 substCase (pattern, expr) =
65 if Pattern.member old pattern
66 then (pattern, expr)
67 else (pattern, f expr)
69 Data tag values ->
70 Data tag (map f values)
72 Access record field ->
73 Access (f record) field
75 Update record fields ->
76 Update (f record) (map (second f) fields)
78 Record fields ->
79 Record (map (second f) fields)
81 Literal _ ->
82 expression
84 GLShader _ _ _ ->
85 expression
87 Port impl ->
88 Port $
89 case impl of
90 In _ _ ->
91 impl
93 Out name expr tipe ->
94 Out name (f expr) tipe
96 Task name expr tipe ->
97 Task name (f expr) tipe