From d405072dbf166cc8c0f9ed49e4edb26afff498b3 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Thu, 15 Aug 2024 20:13:56 +0200
Subject: Access multidimensional arrays

---
 lib/Language/Elna/AST.hs | 56 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 20 deletions(-)

(limited to 'lib/Language/Elna/AST.hs')

diff --git a/lib/Language/Elna/AST.hs b/lib/Language/Elna/AST.hs
index 189fcb5..ac86e63 100644
--- a/lib/Language/Elna/AST.hs
+++ b/lib/Language/Elna/AST.hs
@@ -1,5 +1,7 @@
 module Language.Elna.AST
-    ( Declaration(..)
+    ( VariableAccess(..)
+    , Condition(..)
+    , Declaration(..)
     , Expression(..)
     , Identifier(..)
     , Literal(..)
@@ -44,21 +46,25 @@ instance Show Literal
         | boolean = "true"
         | otherwise = "false"
 
+data VariableAccess
+    = VariableAccess Identifier
+    | ArrayAccess VariableAccess Expression
+    deriving Eq
+
+instance Show VariableAccess
+  where
+    show (VariableAccess variableName) = show variableName
+    show (ArrayAccess arrayAccess elementIndex) =
+        concat [show arrayAccess, "[", show elementIndex, "]"]
+
 data Expression
-    = VariableExpression Identifier
+    = VariableExpression VariableAccess
     | LiteralExpression Literal
     | NegationExpression Expression
     | SumExpression Expression Expression
     | SubtractionExpression Expression Expression
     | ProductExpression Expression Expression
     | DivisionExpression Expression Expression
-    | EqualExpression Expression Expression
-    | NonEqualExpression Expression Expression
-    | LessExpression Expression Expression
-    | GreaterExpression Expression Expression
-    | LessOrEqualExpression Expression Expression
-    | GreaterOrEqualExpression Expression Expression
-    | ArrayExpression Expression Expression
     deriving Eq
 
 instance Show Expression
@@ -70,20 +76,30 @@ instance Show Expression
     show (SubtractionExpression lhs rhs) = concat [show lhs, " - ", show rhs]
     show (ProductExpression lhs rhs) = concat [show lhs, " * ", show rhs]
     show (DivisionExpression lhs rhs) = concat [show lhs, " / ", show rhs]
-    show (EqualExpression lhs rhs) = concat [show lhs, " = ", show rhs]
-    show (NonEqualExpression lhs rhs) = concat [show lhs, " # ", show rhs]
-    show (LessExpression lhs rhs) = concat [show lhs, " < ", show rhs]
-    show (GreaterExpression lhs rhs) = concat [show lhs, " > ", show rhs]
-    show (LessOrEqualExpression lhs rhs) = concat [show lhs, " <= ", show rhs]
-    show (GreaterOrEqualExpression lhs rhs) = concat [show lhs, " >= ", show rhs]
-    show (ArrayExpression arrayExpression indexExpression) =
-        concat [show arrayExpression, "[", show indexExpression, "]"]
+
+data Condition
+    = EqualCondition Expression Expression
+    | NonEqualCondition Expression Expression
+    | LessCondition Expression Expression
+    | GreaterCondition Expression Expression
+    | LessOrEqualCondition Expression Expression
+    | GreaterOrEqualCondition Expression Expression
+    deriving Eq
+
+instance Show Condition
+  where
+    show (EqualCondition lhs rhs) = concat [show lhs, " = ", show rhs]
+    show (NonEqualCondition lhs rhs) = concat [show lhs, " # ", show rhs]
+    show (LessCondition lhs rhs) = concat [show lhs, " < ", show rhs]
+    show (GreaterCondition lhs rhs) = concat [show lhs, " > ", show rhs]
+    show (LessOrEqualCondition lhs rhs) = concat [show lhs, " <= ", show rhs]
+    show (GreaterOrEqualCondition lhs rhs) = concat [show lhs, " >= ", show rhs]
 
 data Statement
     = EmptyStatement
-    | AssignmentStatement Expression Expression
-    | IfStatement Expression Statement (Maybe Statement)
-    | WhileStatement Expression Statement
+    | AssignmentStatement VariableAccess Expression
+    | IfStatement Condition Statement (Maybe Statement)
+    | WhileStatement Condition Statement
     | CompoundStatement [Statement]
     | CallStatement Identifier [Expression]
     deriving Eq
-- 
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