/// <summary>
/// Parse ForStatement
/// </summary>
private void ForStatement()
{
IdentifierRecord controlVariableRecord = new IdentifierRecord();
VariableRecord finalValueRecord = new VariableRecord();
VariableRecord controlStatementRecord = new VariableRecord();
string controlLabelRecord = string.Empty;
string loopLabel = string.Empty;
ControlRecord stepValueRecord = new ControlRecord();
switch(lookAheadToken.tag)
{
case Tags.MP_FOR:
UsedRules.WriteLine("57");
Match((int)Tags.MP_FOR);
ControlVariable(ref controlVariableRecord);
Match((int)Tags.MP_ASSIGN);
InitialValue(ref controlVariableRecord);
analyzer.GenerateLabel(ref controlLabelRecord);
analyzer.GenerateIdPush(controlVariableRecord,ref controlStatementRecord);
StepValue(ref stepValueRecord);
FinalValue(ref finalValueRecord);
analyzer.GenerateBranch(ref loopLabel, stepValueRecord.branchType);
Match((int)Tags.MP_DO);
Statement();
analyzer.GenerateIncrement(ref controlVariableRecord, stepValueRecord.addingOperator);
analyzer.GenerateBranch(ref controlLabelRecord, BranchType.br);
analyzer.GenerateLabel(ref loopLabel);
break;
default:
Error("Expecting ForStatement found " + lookAheadToken.lexeme);
break;
}
}
/// <summary>
/// Parse StepValue
/// </summary>
/// <param name="stepValueRecord"></param>
private void StepValue(ref ControlRecord stepValueRecord)
{
switch (lookAheadToken.tag)
{
case Tags.MP_TO: // "to"
UsedRules.WriteLine("60");
stepValueRecord.addingOperator = "add";
stepValueRecord.branchType = BranchType.bgt;
Match((int)Tags.MP_TO);
break;
case Tags.MP_DOWNTO: //"downto"
UsedRules.WriteLine("61");
stepValueRecord.addingOperator = "sub";
stepValueRecord.branchType = BranchType.blt;
Match((int)Tags.MP_DOWNTO);
break;
default:
Error("Expecting StepValue but found " + lookAheadToken.lexeme);
break;
}
}