blob: b7882142aef82c73fb54b088781486f75a117692 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
module Micro.Env where
import Data.Map qualified as Map
import Data.Maybe (isJust)
import Micro.Ast qualified as A
import Micro.Error
import Text.Parsec (SourcePos)
data Sym = Sym
{ symId :: A.Ident,
symType :: A.Type,
symPriv :: Bool,
symRef :: Bool,
symPos :: SourcePos
}
deriving (Show)
-- XXX: this name is not good
toSym :: Bool -> A.FuncParam -> Sym
toSym ref (a, b, c, d) = Sym a b c ref d
type SymMap = Map.Map A.Ident Sym
data Env = Env SymMap (Maybe Env) deriving (Show)
emptyEnv :: Env
emptyEnv = Env Map.empty Nothing
-- | @getSymB local env ident@ checks @local@ parameter to tell if we look on
-- the local environment or if we should check also in the parent(s).
getSymB :: Bool -> Env -> A.Ident -> Maybe Sym
getSymB local (Env m parent) id =
case (local, Map.lookup id m) of
(False, Nothing) -> do
p <- parent
getSym p id
(_, s) -> s
-- | Gets a symbol checking all the environments.
getSym :: Env -> A.Ident -> Maybe Sym
getSym = getSymB False
-- | Gets a symbol checking the local environment.
getSyml :: Env -> A.Ident -> Maybe Sym
getSyml = getSymB True
-- | Checks if a symbol exists.
existsSym :: Env -> A.Ident -> Bool
existsSym env sym = isJust $ getSym env sym
-- | Checks if a local symbol exists in the local environment.
existsSyml :: Env -> A.Ident -> Bool
existsSyml env sym = isJust $ getSyml env sym
-- | @addSym e s@ add symbol @s@ to enviroment @e@ and returns the modified
-- environment. It will create a new enviroment if the symbol already exists
-- (shadowing).
addSym :: Env -> Sym -> Env
addSym env@(Env m parent) sym = case getSym env sym.symId of
Nothing -> Env (Map.insert sym.symId sym m) parent
Just _ -> Env (Map.singleton sym.symId sym) $ Just env
-- | @addEnv e@ adds a new local environment using @e@ as parent.
addEnv :: Env -> Env
addEnv env = Env Map.empty $ Just env
-- | @addSymUniq e s@ adds a local symbol @s@ to the enviroment @e@ if it
-- doesn't exist.
addSymUniq :: Env -> Sym -> Either Error Env
addSymUniq ev sym = case getSyml ev sym.symId of
Nothing -> Right $ addSym ev sym
Just other -> Left $ Error AlreadyDefined ("\"" ++ sym.symId ++ "\" already defined in " ++ show other.symPos) sym.symPos
|
