public void CompileWhile()
{
string secondLabel = "LABEL_" + labelIndex++;
string firstLabel = "LABEL_" + labelIndex++;
vmWriter.WriteLabel(firstLabel);
jtoken.Advance();
CompileExpression();
jtoken.Advance();
vmWriter.WriteArithmetic("not");
vmWriter.WriteIf(secondLabel);
jtoken.Advance();
CompileStatements();
vmWriter.WriteGoto(firstLabel);
vmWriter.WriteLabel(secondLabel);
}
public void compileIfStatement()
{
string currentInstruction;
finalInstructions.Add("<ifStatement>");
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // if
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // (
List <string> expressionTermList = new List <string>();
finalInstructions.Add("<expression>");
compileTerm();
finalInstructions.Add("</expression>");
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // )
currentVMWriter.WriteIf($"IF_TRUE{ifCount}");
currentVMWriter.WriteGoto($"IF_FALSE{ifCount}");
currentVMWriter.WriteLabel($"IF_TRUE{ifCount}");
int currentIfCount = ifCount;
ifCount++;
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // {
compileStatements();
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // }
//ifCount--;
if (nextChar() == "else")
{
currentVMWriter.WriteGoto($"IF_END{currentIfCount}");
currentVMWriter.WriteLabel($"IF_FALSE{currentIfCount}");
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // else
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // {
compileStatements();
currentInstruction = printAndAdvance("XML");
finalInstructions.Add(currentInstruction); // }
currentVMWriter.WriteLabel($"IF_END{currentIfCount}");
}
else
{
currentVMWriter.WriteLabel($"IF_FALSE{currentIfCount}");
}
finalInstructions.Add("</ifStatement>");
}
