while loops working

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

@@ -222,6 +222,9 @@ public class Generator
             case VariableReassignmentNode variableReassignment:
                 GenerateVariableReassignment(variableReassignment, func);
                 break;
+            case WhileNode whileStatement:
+                GenerateWhile(whileStatement, func);
+                break;
             default:
                 throw new ArgumentOutOfRangeException(nameof(statement));
         }
@@ -278,6 +281,19 @@ public class Generator
         _builder.AppendLine($"    mov [rbp - {variable.Offset}], rax");
     }
 
+    private void GenerateWhile(WhileNode whileStatement, LocalFunc func)
+    {
+        var startLabel = _labelFactory.Create();
+        var endLabel = _labelFactory.Create();
+        _builder.AppendLine($"{startLabel}:");
+        GenerateExpression(whileStatement.Condition, func);
+        _builder.AppendLine("    cmp rax, 0");
+        _builder.AppendLine($"    je {endLabel}");
+        GenerateBlock(whileStatement.Body, func);
+        _builder.AppendLine($"    jmp {startLabel}");
+        _builder.AppendLine($"{endLabel}:");
+    }
+
     private void GenerateExpression(ExpressionNode expression, LocalFunc func)
     {
         switch (expression)
@@ -366,7 +382,7 @@ public class Generator
             case DelegateType:
                 throw new NotSupportedException($"Comparison on type {type.GetType().Name} is not supported");
             case PrimitiveType:
-                _builder.AppendLine("    cmp rax, rax");
+                _builder.AppendLine("    cmp rax, rbx");
                 break;
             case StringType:
                 _builder.AppendLine("    mov rdi, rax");

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

@@ -8,11 +8,12 @@ public class Lexer
     { 
         ["func"] = Symbol.Func,
         ["extern"] = Symbol.Extern,
-        ["return"] = Symbol.Return,
         ["import"] = Symbol.Import,
         ["let"] = Symbol.Let,
         ["if"] = Symbol.If,
         ["else"] = Symbol.Else,
+        ["while"] = Symbol.While,
+        ["return"] = Symbol.Return,
     };
 
     private static readonly Dictionary<char[], Symbol> Chians = new()

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

@@ -15,6 +15,7 @@ public enum Symbol
     Let,
     If,
     Else,
+    While,
     Semicolon,
     Colon,
     OpenParen,

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

@@ -163,25 +163,14 @@ public class Parser
             }
             case SymbolToken symbol:
             {
-                switch (symbol.Symbol)
+                return symbol.Symbol switch
                 {
-                    case Symbol.Return:
-                    {
-                        return ParseReturn();
-                    }
-                    case Symbol.Let:
-                    {
-                        return ParseVariableAssignment();
-                    }
-                    case Symbol.If:
-                    {
-                        return ParseIf();
-                    }
-                    default:
-                    {
-                        throw new Exception($"Unexpected symbol {symbol.Symbol}");
-                    }
-                }   
+                    Symbol.Return => ParseReturn(),
+                    Symbol.Let => ParseVariableAssignment(),
+                    Symbol.If => ParseIf(),
+                    Symbol.While => ParseWhile(),
+                    _ => throw new Exception($"Unexpected symbol {symbol.Symbol}")
+                };
             }
             default:
             {
@@ -228,6 +217,13 @@ public class Parser
         return new IfNode(condition, body, elseStatement);
     }
 
+    private WhileNode ParseWhile()
+    {
+        var condition = ParseExpression();
+        var body = ParseBlock();
+        return new WhileNode(condition, body);
+    }
+
     private ExpressionNode ParseExpression(int precedence = 0)
     {
         var left = ParsePrimaryExpression();

Nub.Lang/Nub.Lang/Frontend/Parsing/WhileNode.cs

@@ -0,0 +1,7 @@
+namespace Nub.Lang.Frontend.Parsing;
+
+public class WhileNode(ExpressionNode condition, BlockNode body) : StatementNode
+{
+    public ExpressionNode Condition { get; } = condition;
+    public BlockNode Body { get; } = body;
+}

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

@@ -101,6 +101,9 @@ public class ExpressionTyper
             case VariableReassignmentNode variableReassignment:
                 PopulateVariableReassignment(variableReassignment);
                 break;
+            case WhileNode whileStatement:
+                PopulateWhileStatement(whileStatement);
+                break;
             default:
                 throw new ArgumentOutOfRangeException(nameof(statement));
         }
@@ -155,6 +158,12 @@ public class ExpressionTyper
         PopulateExpression(variableReassignment.Value);
     }
 
+    private void PopulateWhileStatement(WhileNode whileStatement)
+    {
+        PopulateExpression(whileStatement.Condition);
+        PopulateBlock(whileStatement.Body);
+    }
+
     private void PopulateExpression(ExpressionNode expression)
     {
         switch (expression)

input/program.nub

@@ -1,21 +1,9 @@
 import "core";
 
-let KB = 1024;
-let MB = KB * 1024;
-let GB = MB * 1024;
-let TB = GB * 1024;
-
 func main() {
-    println("test");
-    println(true);
-    
-    if strlen("1") == 1 {
-        println("1");
-    } else if false {
-        println("2");
-    } else if true {
-        println("3");
-    } else {
-        println("4");
+    let i = 1;
+    while i <= 10 {
+        println("uwu");
+        i = i + 1;
     }
 }