Fix array access

Nub.Lang/Nub.Lang/Backend/Custom/Generator.cs

@@ -12,6 +12,7 @@ public class Generator
     private readonly SymbolTable _symbolTable;
     private readonly StringBuilder _builder;
     private readonly LabelFactory _labelFactory;
+    private readonly Stack<(string StartLabel, string EndLabel)> _loops;
     
     public Generator(List<DefinitionNode> definitions)
     {
@@ -19,6 +20,7 @@ public class Generator
         _builder = new StringBuilder();
         _labelFactory = new LabelFactory();
         _symbolTable = new SymbolTable(_labelFactory);
+        _loops = [];
 
         foreach (var globalVariableDefinition in definitions.OfType<GlobalVariableDefinitionNode>())
         {
@@ -213,6 +215,12 @@ public class Generator
             case ArrayIndexAssignmentNode arrayIndexAssignment:
                 GenerateArrayIndexAssignment(arrayIndexAssignment, func);
                 break;
+            case BreakNode:
+                GenerateBreak();
+                break;
+            case ContinueNode:
+                GenerateContinue();
+                break;
             case FuncCallStatementNode funcCallStatement:
                 GenerateFuncCall(funcCallStatement.FuncCall, func);
                 break;
@@ -239,6 +247,16 @@ public class Generator
         }
     }
 
+    private void GenerateBreak()
+    {
+        _builder.AppendLine($"    jmp {_loops.Peek().EndLabel}");
+    }
+    
+    private void GenerateContinue()
+    {
+        _builder.AppendLine($"    jmp {_loops.Peek().StartLabel}");
+    }
+
     private void GenerateArrayIndexAssignment(ArrayIndexAssignmentNode arrayIndexAssignment, LocalFunc func)
     {
         GenerateExpression(arrayIndexAssignment.Value, func);
@@ -303,11 +321,14 @@ public class Generator
     {
         var startLabel = _labelFactory.Create();
         var endLabel = _labelFactory.Create();
+        
         _builder.AppendLine($"{startLabel}:");
         GenerateExpression(whileStatement.Condition, func);
         _builder.AppendLine("    cmp rax, 0");
         _builder.AppendLine($"    je {endLabel}");
+        _loops.Push((startLabel, endLabel));
         GenerateBlock(whileStatement.Body, func);
+        _loops.Pop();
         _builder.AppendLine($"    jmp {startLabel}");
         _builder.AppendLine($"{endLabel}:");
     }
@@ -627,25 +648,25 @@ public class Generator
         GenerateExpression(index, func);
         _builder.AppendLine("    push rax");
         GenerateIdentifier(identifier, func);
-        _builder.AppendLine("    pop rcx");
+        _builder.AppendLine("    pop rdx");
         
         // rcx now holds the length of the array which we can use to check bounds
         _builder.AppendLine("    mov rcx, [rax]");
-        _builder.AppendLine("    cmp rcx, rcx");
+        _builder.AppendLine("    cmp rdx, rcx");
         if (ZeroBasedIndexing)
         {
             _builder.AppendLine("    jge array_out_of_bounds");
-            _builder.AppendLine("    cmp rcx, 0");
+            _builder.AppendLine("    cmp rdx, 0");
         }
         else
         {
             _builder.AppendLine("    jg array_out_of_bounds");
-            _builder.AppendLine("    cmp rcx, 1");
+            _builder.AppendLine("    cmp rdx, 1");
         }
         _builder.AppendLine("    jl array_out_of_bounds");
 
-        _builder.AppendLine("    inc rcx");
+        _builder.AppendLine("    inc rdx");
-        _builder.AppendLine("    shl rcx, 3");
+        _builder.AppendLine("    shl rdx, 3");
-        _builder.AppendLine("    add rax, rcx");
+        _builder.AppendLine("    add rax, rdx");
     }
 }

Nub.Lang/Nub.Lang/Frontend/Lexing/Lexer.cs

@@ -13,6 +13,8 @@ public class Lexer
         ["if"] = Symbol.If,
         ["else"] = Symbol.Else,
         ["while"] = Symbol.While,
+        ["break"] = Symbol.Break,
+        ["continue"] = Symbol.Continue,
         ["return"] = Symbol.Return,
         ["new"] = Symbol.New,
     };

Nub.Lang/Nub.Lang/Frontend/Lexing/SymbolToken.cs

@@ -16,6 +16,8 @@ public enum Symbol
     If,
     Else,
     While,
+    Break,
+    Continue,
     Semicolon,
     Colon,
     OpenParen,

Nub.Lang/Nub.Lang/Frontend/Parsing/BreakNode.cs

@@ -0,0 +1,3 @@
+namespace Nub.Lang.Frontend.Parsing;
+
+public class BreakNode : StatementNode;

Nub.Lang/Nub.Lang/Frontend/Parsing/ContinueNode.cs

@@ -0,0 +1,3 @@
+namespace Nub.Lang.Frontend.Parsing;
+
+public class ContinueNode : StatementNode;

Nub.Lang/Nub.Lang/Frontend/Parsing/Parser.cs

@@ -178,6 +178,8 @@ public class Parser
                     Symbol.Let => ParseVariableAssignment(),
                     Symbol.If => ParseIf(),
                     Symbol.While => ParseWhile(),
+                    Symbol.Break => ParseBreak(),
+                    Symbol.Continue => ParseContinue(),
                     _ => throw new Exception($"Unexpected symbol {symbol.Symbol}")
                 };
             }
@@ -233,6 +235,18 @@ public class Parser
         return new WhileNode(condition, body);
     }
 
+    private BreakNode ParseBreak()
+    {
+        ExpectSymbol(Symbol.Semicolon);
+        return new BreakNode();
+    }
+
+    private ContinueNode ParseContinue()
+    {
+        ExpectSymbol(Symbol.Semicolon);
+        return new ContinueNode();
+    }
+    
     private ExpressionNode ParseExpression(int precedence = 0)
     {
         var left = ParsePrimaryExpression();

Nub.Lang/Nub.Lang/Frontend/Typing/ExpressionTyper.cs

@@ -86,6 +86,9 @@ public class ExpressionTyper
             case ArrayIndexAssignmentNode arrayIndexAssignment:
                 PopulateArrayIndexAssignment(arrayIndexAssignment);
                 break;
+            case BreakNode:
+            case ContinueNode:
+                break;
             case FuncCallStatementNode funcCall:
                 PopulateFuncCallStatement(funcCall);
                 break;

input/program.nub

@@ -1,5 +1,20 @@
 import "core";
 
 func main() {
-    println(69);
+    let some_string = "test";
+    println(some_string);
+    
+    let some_array = new Array<int64>(2);
+    some_array[1] = 1;
+    some_array[2] = 2;
+    
+    let i = 1;
+    
+    println(some_array[1]);
+    println(some_array[2]);
+    
+    while i <= arr_size(some_array) {
+        println(some_array[i]);
+        i = i + 1;
+    }
 }