From 3d2b80cf454e682ba1fcd094465b7ee1a94297dd Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Thu, 1 Sep 2022 22:34:28 +0100
Subject: Variable declaration

---
 src/Ast.hs      |  3 ++-
 src/Compiler.hs | 15 +++++++++++++--
 src/Lexer.hs    |  4 ++--
 src/Parser.hs   | 14 ++++++++++++--
 4 files changed, 29 insertions(+), 7 deletions(-)

(limited to 'src')

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
 
-- 
cgit v1.2.3