Variable declaration

5 files changed, 84 insertions, 33 deletions

diff --git a/src/Ast.hs b/src/Ast.hs
index 3d351c6..af87a8b 100644
--- a/src/Ast.hs
+++ b/src/Ast.hs
@@ -23,7 +23,8 @@ data Expr
   = Num Integer SourcePos
   | Bool' Bool SourcePos
   | BinOp Op Expr Expr
-  | Var Ident SourcePos
+  | Variable Ident SourcePos
+  | Var Ident Type Expr SourcePos
   | -- fn [params] return body private anomyous pos
     Func Ident [FuncParam] (Maybe Type) [Expr] Bool Bool SourcePos
   | Call Expr [Expr] SourcePos
diff --git a/src/Compiler.hs b/src/Compiler.hs
index a8cca5d..a708f96 100644
--- a/src/Compiler.hs
+++ b/src/Compiler.hs
@@ -92,7 +92,7 @@ verifyFuncType ident params ret pos = do
       map
         ( \(id, t, pos) ->
             if not (definedType t)
-              then Just $ Error UndefinedType ("undefined type in \"" ++ id ++ "\"") pos
+              then Just $ Error UndefinedType ("undefined type in function declaration \"" ++ id ++ "\"") pos
               else Nothing
         )
         params
@@ -145,6 +145,17 @@ compile x = do
             Nothing -> return $ Right rtyp
         Right _ -> addError $ Error NonCallable "non callable value in function call" pos
         _ -> return $ Right Nothing
+    (A.Var ident typ val pos) -> do
+      (ev, errs) <- get
+      (ev, errs) <- return $ foldlEither addSymUniq (ev, errs) [(ident, typ, pos)]
+      errs <-
+        return $
+          if not (definedType typ)
+            then Error UndefinedType ("undefined type in variable declaration \"" ++ ident ++ "\"") pos : errs
+            else errs
+      -- TODO: typecheck value
+      put (ev, errs)
+      return $ Right $ Just typ
     (A.Return value pos) -> do
       (ev, errs) <- get
       case getSyml ev "$fn$" of
@@ -154,7 +165,7 @@ compile x = do
           case r of
             Just err -> addError $ Error TypeError err pos
             Nothing -> return $ Right rtyp
-    (A.Var ident pos) -> do
+    (A.Variable ident pos) -> do
       (ev, errs) <- get
       case getSym ev ident of
         Just (_, t, _) -> return $ Right $ Just t
diff --git a/src/Lexer.hs b/src/Lexer.hs
index 1778b21..7d09752 100644
--- a/src/Lexer.hs
+++ b/src/Lexer.hs
@@ -9,8 +9,8 @@ import qualified Text.Parsec.Token as T
 scanner :: T.TokenParser ()
 scanner = T.makeTokenParser style
   where
-    ops = ["+", "*", "-", ";"]
-    names = ["module", "private", "def", "return", "->", "true", "false"]
+    ops = ["+", "*", "-", ";", "="]
+    names = ["module", "private", "var", "def", "return", "->", "true", "false"]
     style =
       emptyDef
         { T.commentLine = "#",
diff --git a/src/Parser.hs b/src/Parser.hs
index ea698c8..f341bc2 100644
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -43,7 +43,7 @@ variable :: Parser Expr
 variable = do
   pos <- getPosition
   var <- identifier
-  return $ Var var pos
+  return $ Variable var pos
 
 typ :: Parser Type
 typ = do
@@ -116,6 +116,16 @@ call = do
   args <- parens $ commaSep expr
   return $ Call ident args pos
 
+var :: Parser Expr
+var = do
+  pos <- getPosition
+  reserved "var"
+  (ident, typ, _) <- arg
+  reservedOp "=" <?> "assignation"
+  value <- expr
+  reservedOp ";"
+  return $ Var ident typ value pos
+
 factor :: Parser Expr
 factor =
   number
@@ -150,7 +160,7 @@ program = do
   n <-
     many $ do
       function
-        -- TODO: variable decl
+        <|> var
         <|> statement <?> "statement"
   return $ [m] ++ n
 
diff --git a/test/Language.hs b/test/Language.hs
index 12c724a..9a3ca5d 100644
--- a/test/Language.hs
+++ b/test/Language.hs
@@ -89,7 +89,7 @@ testCase6 =
         \fn();"
         [ A.Module "main" $ newPos "test" 1 1,
           A.Func "fn" [] Nothing [] False False $ newPos "test" 2 1,
-          A.Call (A.Var "fn" $ newPos "test" 3 1) [] $ newPos "test" 3 1
+          A.Call (A.Variable "fn" $ newPos "test" 3 1) [] $ newPos "test" 3 1
         ]
 
 testCase7 =
@@ -102,7 +102,7 @@ testCase7 =
         \fn(10);"
         [ A.Module "main" $ newPos "test" 1 1,
           A.Func "fn" [("a", A.Type "u8", newPos "test" 2 8)] Nothing [] False False $ newPos "test" 2 1,
-          A.Call (A.Var "fn" $ newPos "test" 3 1) [A.Num 10 $ newPos "test" 3 4] $ newPos "test" 3 1
+          A.Call (A.Variable "fn" $ newPos "test" 3 1) [A.Num 10 $ newPos "test" 3 4] $ newPos "test" 3 1
         ]
 
 testCase8 =
@@ -126,7 +126,7 @@ testCase9 =
         \def fn() {\n\
         \fn(); }"
         [ A.Module "main" $ newPos "test" 1 1,
-          A.Func "fn" [] Nothing [A.Call (A.Var "fn" $ newPos "test" 3 1) [] $ newPos "test" 3 1] False False $ newPos "test" 2 1
+          A.Func "fn" [] Nothing [A.Call (A.Variable "fn" $ newPos "test" 3 1) [] $ newPos "test" 3 1] False False $ newPos "test" 2 1
         ]
 
 testCase10 =
@@ -145,12 +145,12 @@ testCase10 =
             "fn2"
             [("f", A.FuncType [] Nothing, newPos "test" 3 9)]
             Nothing
-            [ A.Call (A.Var "f" $ newPos "test" 4 1) [] $ newPos "test" 4 1
+            [ A.Call (A.Variable "f" $ newPos "test" 4 1) [] $ newPos "test" 4 1
             ]
             False
             False
             $ newPos "test" 3 1,
-          A.Call (A.Var "fn2" $ newPos "test" 5 1) [A.Var "fn1" $ newPos "test" 5 5] $ newPos "test" 5 1
+          A.Call (A.Variable "fn2" $ newPos "test" 5 1) [A.Variable "fn1" $ newPos "test" 5 5] $ newPos "test" 5 1
         ]
 
 testCase11 =
@@ -167,11 +167,11 @@ testCase11 =
             "fn"
             [("f", A.FuncType [] Nothing, newPos "test" 2 8)]
             Nothing
-            [A.Call (A.Var "f" $ newPos "test" 3 1) [] $ newPos "test" 3 1]
+            [A.Call (A.Variable "f" $ newPos "test" 3 1) [] $ newPos "test" 3 1]
             False
             False
             $ newPos "test" 2 1,
-          A.Call (A.Var "fn" $ newPos "test" 4 1) [A.Func "lambda@4,4" [] Nothing [] True True $ newPos "test" 4 4] $ newPos "test" 4 1
+          A.Call (A.Variable "fn" $ newPos "test" 4 1) [A.Func "lambda@4,4" [] Nothing [] True True $ newPos "test" 4 4] $ newPos "test" 4 1
         ]
 
 testCase12 =
@@ -184,9 +184,19 @@ testCase12 =
           A.Call (A.Func "lambda@2,1" [] Nothing [] True True $ newPos "test" 2 1) [] $ newPos "test" 2 1
         ]
 
+testCase13 =
+  TestLabel "parse a variable declaration" $
+    TestCase $
+      assertAst
+        "module main\n\
+        \var a: u8 = 10;"
+        [ A.Module "main" $ newPos "test" 1 1,
+          A.Var "a" (A.Type "u8") (A.Num 10 $ newPos "test" 2 13) $ newPos "test" 2 1
+        ]
+
 -- test errors
 
-testCase13 =
+testCaseE1 =
   TestLabel "invalid return value (empty return)" $
     TestCase $
       expectError
@@ -194,7 +204,7 @@ testCase13 =
         \def fn(): u8 { return; }"
         E.TypeError
 
-testCase14 =
+testCaseE2 =
   TestLabel "invalid return value" $
     TestCase $
       expectError
@@ -202,7 +212,7 @@ testCase14 =
         \def fn(): u16 { return 1; }"
         E.TypeError
 
-testCase15 =
+testCaseE3 =
   TestLabel "return without function" $
     TestCase $
       expectError
@@ -210,7 +220,7 @@ testCase15 =
         \return;"
         E.UnexpectedReturn
 
-testCase16 =
+testCaseE4 =
   TestLabel "symbol already defined" $
     TestCase $
       expectError
@@ -219,7 +229,7 @@ testCase16 =
         \def fn() { }"
         E.AlreadyDefined
 
-testCase17 =
+testCaseE5 =
   TestLabel "parameter already defined" $
     TestCase $
       expectError
@@ -227,7 +237,7 @@ testCase17 =
         \def fn(a: u8, a: u8) { }\n"
         E.AlreadyDefined
 
-testCase18 =
+testCaseE6 =
   TestLabel "call on non callable" $
     TestCase $
       expectError
@@ -235,7 +245,7 @@ testCase18 =
         \def fn(a: u8): u8 { return a(); }\n"
         E.NonCallable
 
-testCase19 =
+testCaseE7 =
   TestLabel "undefined variable" $
     TestCase $
       expectError
@@ -243,7 +253,7 @@ testCase19 =
         \def fn(a: u8): u8 { return undef; }\n"
         E.Undefined
 
-testCase20 =
+testCaseE8 =
   TestLabel "lambdas can use local variables only" $
     TestCase $
       expectError
@@ -253,7 +263,7 @@ testCase20 =
         \}\n"
         E.Undefined
 
-testCase21 =
+testCaseE9 =
   TestLabel "undefined type in function parameters" $
     TestCase $
       expectError
@@ -263,7 +273,7 @@ testCase21 =
         \}\n"
         E.UndefinedType
 
-testCase22 =
+testCaseE10 =
   TestLabel "undefined type in function return type" $
     TestCase $
       expectError
@@ -273,6 +283,22 @@ testCase22 =
         \}\n"
         E.UndefinedType
 
+testCaseE11 =
+  TestLabel "already defined variable" $
+    TestCase $
+      expectError
+        "module main\n\
+        \var a: u8 = 1; var a: u8 = 1;\n"
+        E.AlreadyDefined
+
+testCaseE12 =
+  TestLabel "undefined type in variable declaration" $
+    TestCase $
+      expectError
+        "module main\n\
+        \var a: undef = 1;\n"
+        E.UndefinedType
+
 language =
   [ testCase2,
     testCase3,
@@ -286,13 +312,16 @@ language =
     testCase11,
     testCase12,
     testCase13,
-    testCase14,
-    testCase15,
-    testCase16,
-    testCase17,
-    testCase18,
-    testCase19,
-    testCase20,
-    testCase21,
-    testCase22
+    testCaseE1,
+    testCaseE2,
+    testCaseE3,
+    testCaseE4,
+    testCaseE5,
+    testCaseE6,
+    testCaseE7,
+    testCaseE8,
+    testCaseE9,
+    testCaseE10,
+    testCaseE11,
+    testCaseE12
   ]