private static void MakeLoopEnd(TokenizerOutput program, TLine line, Stack <LoopData> loopStack)
{
if (loopStack.Count < 1)
{
throw new TokenizerException(line, "Misplaced NEXT");
}
LoopData data = loopStack.Pop();
var next = (KwNext)line.Statement;
if (data.LoopVariable.Name != next.Variable.Name)
{
throw new TokenizerException(line, "NEXT Error : Unknown variable " + next.Variable.Name);
}
// step 1: change the variable
var add = new NumBinaryOperator(data.LoopVariable, data.StepVariable, "+");
var assign = new NumBinaryOperator(data.LoopVariable, add, "=");
program.Program.Add(line.Clone(assign));
// step 2: goto to the begining
var gt = new KwrGoto(data.StartLine, true);
program.Program.Add(line.Clone(gt));
// change the top jump condition
((KwrJumpIfTrue)program.Program[data.StartLine].Statement).JumpPos = program.Program.Count;
}
private static void MakeBranch(TokenizerOutput program, TLine line, Stack <LoopData> loopStack)
{
var kwif = (KwIf)line.Statement;
var newIf = new KwrJumpIfNotTrue(kwif.Condition, -1);
program.Program.Add(line.Clone(newIf)); // placeholder
foreach (Statement s in kwif.Statements)
{
TokenizeStatement(program, line.Clone(s), loopStack);
}
if (kwif.ElseStatements == null)
{
newIf.JumpPos = program.Program.Count;
}
else
{
var gt = new KwrGoto(-1, true);
program.Program.Add(line.Clone(gt));
newIf.JumpPos = program.Program.Count;
foreach (Statement s in kwif.ElseStatements)
{
TokenizeStatement(program, line.Clone(s), loopStack);
}
gt.JumpPos = program.Program.Count;
}
}