FOR

Program.cs

@@ -3,6 +3,7 @@ using System.IO;
 using System.Text;
 using System.Collections.Generic;
 
+// === ENTRY POINT ===
 class Program {
     static int Main(string[] args) {
         if (args.Length < 2) {
@@ -31,6 +32,7 @@ public abstract class Stmt:StNode{}
 public class AssignStmt:Stmt{ public string Target; public Expr Expr; }
 public class IfStmt:Stmt{ public Expr Cond; public List<Stmt> ThenStmts=new(); public List<Stmt> ElseStmts=new(); }
 public class WhileStmt:Stmt{ public Expr Cond; public List<Stmt> Body=new(); }
+public class ForStmt:Stmt{ public string Var; public Expr Start, End, Step = new IntExpr(1); public List<Stmt> Body=new(); }
 
 public abstract class Expr:StNode{}
 public class IntExpr:Expr{ public int Value; public IntExpr(int v){Value=v;} }
@@ -44,6 +46,7 @@ public enum TokType {
     LT, GT, LE, GE, EQ, NEQ,
     IF, THEN, ELSE, END_IF,
     WHILE, DO, END_WHILE,
+    FOR, TO, BY, END_FOR,
     PROGRAM, VAR, END_VAR, END_PROGRAM,
     EOF
 }
@@ -75,6 +78,10 @@ public class StLexer {
                 "WHILE"=>new Token(TokType.WHILE,s),
                 "DO"=>new Token(TokType.DO,s),
                 "END_WHILE"=>new Token(TokType.END_WHILE,s),
+                "FOR"=>new Token(TokType.FOR,s),
+                "TO"=>new Token(TokType.TO,s),
+                "BY"=>new Token(TokType.BY,s),
+                "END_FOR"=>new Token(TokType.END_FOR,s),
                 _=>new Token(TokType.IDENT,s)
             };
         }
@@ -151,6 +158,7 @@ public class StParser {
     Stmt ParseStmt(){
         if(cur.Type==TokType.IF) return ParseIf();
         if(cur.Type==TokType.WHILE) return ParseWhile();
+        if(cur.Type==TokType.FOR) return ParseFor();
         if(cur.Type==TokType.IDENT){
             var n=cur.Text; Next(); Expect(TokType.ASSIGN);
             var e=ParseExpr(); Expect(TokType.SEMI);
@@ -184,6 +192,26 @@ public class StParser {
         return ws;
     }
 
+    ForStmt ParseFor(){
+        Next(); // FOR
+        string varName = cur.Text; Expect(TokType.IDENT);
+        Expect(TokType.ASSIGN);
+        Expr start = ParseExpr();
+        Expect(TokType.TO);
+        Expr end = ParseExpr();
+        Expr step = new IntExpr(1);
+        if(cur.Type==TokType.BY){
+            Next();
+            step = ParseExpr();
+        }
+        Expect(TokType.DO);
+        var fs = new ForStmt{Var=varName, Start=start, End=end, Step=step};
+        while(cur.Type!=TokType.END_FOR)
+            fs.Body.Add(ParseStmt());
+        Expect(TokType.END_FOR); Expect(TokType.SEMI);
+        return fs;
+    }
+
     Expr ParseExpr()=>ParseCompare();
     Expr ParseCompare(){
         var l=ParseAddSub();
@@ -233,7 +261,7 @@ public class BytecodeEmitter {
         foreach(var s in p.Stmts)
             EmitStmt(s);
 
-        EmitByte(0xF0);
+        EmitByte(0xF0); // Program End
     }
 
     void EmitStmt(Stmt s){
@@ -264,6 +292,37 @@ public class BytecodeEmitter {
                 PatchJump(jzpos,code.Count);
                 break;
 
+            case ForStmt f:
+                // Initialisierung: var := start
+                EmitExpr(f.Start);
+                EmitByte(0x03); EmitU16((ushort)syms[f.Var].Index);
+
+                int cmpPos = code.Count;  // Position des Vergleichs
+                EmitExpr(new VarExpr(f.Var));
+                EmitExpr(f.End);
+                EmitByte(0x16); // LE
+                EmitByte(0x20); int jzFor = code.Count; EmitU16(0); // Jump zum Ende
+
+                // Body
+                foreach(var st in f.Body) EmitStmt(st);
+
+                // Inkrement: i := i + step
+                EmitExpr(new VarExpr(f.Var));
+                EmitExpr(f.Step);
+                EmitByte(0x10); // PLUS
+                EmitByte(0x03); EmitU16((ushort)syms[f.Var].Index);
+
+                // Vergleich erneut, aber wir merken uns den Sprung zum Vergleich
+                EmitByte(0x21); EmitU16((ushort)cmpPos);
+
+                // Patch Jump: Ende der Schleife springt hierhin
+                PatchJump(jzFor, code.Count);
+
+                // Korrektur: Schleifenvariable auf Endwert, falls sie überläuft
+                EmitExpr(f.End);
+                EmitByte(0x03); EmitU16((ushort)syms[f.Var].Index);
+                break;
+
             default: throw new Exception($"Unknown stmt {s.GetType().Name}");
         }
     }