implement for loops

src/main/antlr4/de/hsrm/compiler/Klang/Klang.g4

@@ -31,6 +31,7 @@ statement
   | return_statement
   | whileLoop
   | doWhileLoop
+  | forLoop
   ;
 
 print
@@ -41,6 +42,11 @@ if_statement
   : IF OPAR cond = expression CPAR then = braced_block (ELSE (alt = braced_block | elif = if_statement) )?
   ; 
 
+variableDeclarationOrAssignment
+  : variable_assignment
+  | variable_declaration
+  ;
+
 variable_declaration
   : LET IDENT (EQUAL expression)?
   ;
@@ -66,7 +72,6 @@ expression
   | OPAR lhs=expression GT rhs=expression CPAR #greaterThanExpression
   | OPAR lhs=expression LTE rhs=expression CPAR #lessThanOrEqualToExpression
   | OPAR lhs=expression GTE rhs=expression CPAR #GreaterThanOrEqualToExpression
-  
   | SUB expression #negateExpression
   | functionCall #functionCallExpression
   ;
@@ -92,6 +97,12 @@ doWhileLoop
   : DO braced_block WHILE OPAR cond = expression CPAR SCOL
   ;
 
+forLoop
+  : FOR OPAR init = variableDeclarationOrAssignment SCOL
+             cond = expression SCOL 
+             step = variable_assignment CPAR braced_block
+  ;
+
 PRINT: 'print';
 IF: 'if';
 ELSE: 'else';
@@ -100,6 +111,7 @@ RETURN: 'return';
 LET: 'let';
 WHILE: 'while';
 DO: 'do';
+FOR: 'for';
 
 SCOL: ';';
 OBRK: '{';

src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java

@@ -6,6 +6,7 @@ import java.util.HashSet;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
+import de.hsrm.compiler.Klang.nodes.loops.ForLoop;
 import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 import de.hsrm.compiler.Klang.types.Type;
@@ -81,6 +82,14 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     return new DoWhileLoop((Expression) condition, (Block) block);
   }
 
+  @Override
+  public Node visitForLoop(KlangParser.ForLoopContext ctx) {
+    Node init = this.visit(ctx.init);
+    Node condition = this.visit(ctx.cond);
+    Node step = this.visit(ctx.step);
+    Node block = this.visit(ctx.braced_block());
+    return new ForLoop((Statement) init, (Expression) condition, (VariableAssignment) step, (Block) block);
+  }
 
   @Override
   public Node visitVariable_declaration(KlangParser.Variable_declarationContext ctx) {

src/main/java/de/hsrm/compiler/Klang/nodes/loops/ForLoop.java

@@ -0,0 +1,28 @@
+package de.hsrm.compiler.Klang.nodes.loops;
+
+import de.hsrm.compiler.Klang.nodes.statements.Statement;
+import de.hsrm.compiler.Klang.nodes.statements.VariableAssignment;
+import de.hsrm.compiler.Klang.nodes.Block;
+import de.hsrm.compiler.Klang.nodes.expressions.Expression;
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class ForLoop extends Statement {
+
+    public Statement init;
+    public Expression condition;
+    public VariableAssignment step;
+    public Block block;
+
+    public ForLoop(Statement init, Expression condition, VariableAssignment step, Block block) {
+      this.init = init;
+      this.condition = condition;
+      this.step = step;
+      this.block = block;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+
+}

src/main/java/de/hsrm/compiler/Klang/visitors/EvalVisitor.java

@@ -9,6 +9,7 @@ import de.hsrm.compiler.Klang.nodes.FunctionDefinition;
 import de.hsrm.compiler.Klang.nodes.Program;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
+import de.hsrm.compiler.Klang.nodes.loops.ForLoop;
 import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 
@@ -175,6 +176,20 @@ public class EvalVisitor implements Visitor<Value> {
     return result;
   }
 
+  @Override
+  public Value visit(ForLoop e) {
+    e.init.welcome(this);
+    Value cond = e.condition.welcome(this);
+    Value result = null;
+    while (cond.asInteger() != 0) {
+      result = e.block.welcome(this);
+      e.step.welcome(this);
+      cond = e.condition.welcome(this);
+    }
+    
+    return result;
+  }
+
   @Override
   public Value visit(PrintStatement e) {
     Value value = e.expression.welcome(this);

src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java

@@ -9,6 +9,7 @@ import java.util.TreeSet;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
+import de.hsrm.compiler.Klang.nodes.loops.ForLoop;
 import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 
@@ -291,7 +292,7 @@ public class GenASM implements Visitor<Void> {
     this.ex.write(".L" + lblEnd + ":\n");
     return null;
   }
-  
+
   @Override
   public Void visit(WhileLoop e) {
     int lblCond = ++lCount;
@@ -306,7 +307,6 @@ public class GenASM implements Visitor<Void> {
     return null;
   }
 
-
   @Override
   public Void visit(DoWhileLoop e) {
     int lblStart = ++lCount;
@@ -317,6 +317,23 @@ public class GenASM implements Visitor<Void> {
     this.ex.write("    jnz .L" + lblStart + "\n");
     return null;
   }
+  
+  @Override
+  public Void visit(ForLoop e) {
+    int lblStart = ++lCount;
+    int lblEnd = ++lCount;
+    e.init.welcome(this);
+    this.ex.write(".L" + lblStart + ":\n");
+    e.condition.welcome(this);
+    this.ex.write("    cmp $0, %rax\n");
+    this.ex.write("    jz .L" + lblEnd + "\n");
+    e.block.welcome(this);
+    e.step.welcome(this);
+    this.ex.write("    jmp .L" + lblStart + "\n");
+    this.ex.write(".L" + lblEnd + ":\n");
+        
+    return null;
+  }
 
   @Override
   public Void visit(PrintStatement e) {

src/main/java/de/hsrm/compiler/Klang/visitors/GetVars.java

@@ -5,6 +5,7 @@ import java.util.Set;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
+import de.hsrm.compiler.Klang.nodes.loops.ForLoop;
 import de.hsrm.compiler.Klang.nodes.loops.WhileLoop;
 import de.hsrm.compiler.Klang.nodes.statements.*;
 
@@ -135,6 +136,15 @@ class GetVars implements Visitor<Void> {
     return null;
   }
 
+  @Override
+  public Void visit(ForLoop e) {
+    e.init.welcome(this);
+    e.condition.welcome(this);
+    e.step.welcome(this);
+    e.block.welcome(this);
+    return null;
+  }
+
   @Override
   public Void visit(PrintStatement e) {
     e.expression.welcome(this);

src/main/java/de/hsrm/compiler/Klang/visitors/PrettyPrintVisitor.java

@@ -224,6 +224,19 @@ public class PrettyPrintVisitor implements Visitor<Void> {
     return null;
   }
 
+  @Override
+  public Void visit(ForLoop e) {
+    ex.write("for (");
+    e.init.welcome(this);
+    ex.write(" ");
+    e.condition.welcome(this);
+    ex.write("; ");
+    e.step.welcome(this);
+    ex.write(") ");
+    e.block.welcome(this);
+    return null;
+  }
+
   @Override
   public Void visit(PrintStatement e) {
     ex.write("print ");
@@ -241,7 +254,6 @@ public class PrettyPrintVisitor implements Visitor<Void> {
       e.expression.welcome(this);
     }
 
-    ex.write(";");
     return null;
   }
 
@@ -249,7 +261,6 @@ public class PrettyPrintVisitor implements Visitor<Void> {
   public Void visit(VariableAssignment e) {
     ex.write(e.name + " = ");
     e.expression.welcome(this);
-    ex.write(";");
     return null;
   }
 
@@ -268,6 +279,9 @@ public class PrettyPrintVisitor implements Visitor<Void> {
     for (Statement stmt : e.statements) {
       ex.nl();
       stmt.welcome(this);
+      if (stmt.getClass() == VariableAssignment.class || stmt.getClass() == VariableDeclaration.class) {
+        ex.write(";");
+      }
     }
     ex.subIndent();
     ex.nl();

src/main/java/de/hsrm/compiler/Klang/visitors/Visitor.java

@@ -25,6 +25,7 @@ public interface Visitor<R> {
     R visit(IfStatement e);
     R visit(WhileLoop e);
     R visit(DoWhileLoop e);
+    R visit(ForLoop e);
     R visit(PrintStatement e);
     R visit(VariableDeclaration e);
     R visit(VariableAssignment e);

src/test/loop/loop.c

@@ -2,11 +2,11 @@
 #include "loop.h"
 
 void printLoopSuccess(char* name, int x,  int expected, int result) {
-  printf("SUCCESS:\t%s(%d)\tGOT: %d\tExpected: %d\n", name, x, result, expected);
+  printf("\033[0;32mSUCCESS:\t%s(%d)\tGOT: %d\tExpected: %d\033[0;0m\n", name, x, result, expected);
 }
 
 void printLoopError(char* name, int x, int expected, int result) {
-  printf("ERROR:\t\t%s(%d)\tGOT: %d\tExpected: %d\n", name, x, result, expected);
+  printf("\033[0;31mERROR:\t\t%s(%d)\tGOT: %d\tExpected: %d\033[0;0m\n", name, x, result, expected);
 }
 
 int loopTest(char* name, int x, int expected, int result) {
@@ -25,6 +25,8 @@ int runLoopTests() {
   failed += loopTest("while", 5, 5, myWhile(5));
   failed += loopTest("doWhile", 0, 1, myDoWhile(0));
   failed += loopTest("doWhile", 1, 1, myDoWhile(1));
+  failed += loopTest("for", 5, 5, myFor(5));
+  failed += loopTest("for", 0, 0, myFor(0));
   
   return failed;
 }

src/test/loop/loop.h

@@ -1,2 +1,3 @@
 int myWhile(int x);
-int myDoWhile(int x);
+int myDoWhile(int x);
+int myFor(int x);

src/test/tests.k

@@ -154,4 +154,12 @@ function myDoWhile(end) {
   return cond;
 }
 
+function myFor(end) {
+  let x = 0;
+  for (let i = 0; (i < end); i = (i + 1)) {
+    x = (x + 1);
+  }
+  return x;
+}
+
 add(1, 1);