public static ConditionalStaNode Parse(TokenString tStr, ref int index)
{
int startIndex = index;
if (!tStr.Match(index, TokenType.ifStatement, TokenType.rBraceOpen))
{
return(null);
}
index++;
ExpressionNode condition = Exp.Parse(tStr.GetRangeInBrackets(ref index));
StatementNode ifTrue = Sta.Parse(tStr, ref index);
StatementNode ifFalse = null;
if (tStr.Match(index, TokenType.elseStatement))
{
index++;
ifFalse = Sta.Parse(tStr, ref index);
}
ConditionalStaNode node = new ConditionalStaNode(condition, ifTrue, ifFalse);
return(node);
}
public static CompoundStaNode Parse(TokenString tStr, ref int index)
{
if (!tStr.Match(index, TokenType.cBraceOpen))
{
return(null);
}
index++;
CompoundStaNode node = new CompoundStaNode();
while (!tStr.Match(index, TokenType.cBraceClose))
{
var statementNode = Sta.Parse(tStr, ref index);
if (statementNode != null)
{
node.AddStatement(statementNode);
}
else
{
index++;
}
}
index++;
return(node);
}
public static DoLoopStaNode Parse(TokenString tStr, ref int index)
{
int startIndex = index;
if (!tStr.Match(index, TokenType.doStatement, TokenType.cBraceOpen))
{
return(null);
}
index++;
StatementNode body = Sta.Parse(tStr, ref index);
if (!tStr.Match(index, TokenType.whileStatement, TokenType.rBraceOpen))
{
index = startIndex;
return(null);
}
index++;
ExpressionNode condition = Exp.Parse(tStr.GetRangeInBrackets(ref index));
if (!tStr.Match(index, TokenType.lineEnd))
{
index = startIndex;
return(null);
}
index++;
DoLoopStaNode node = new DoLoopStaNode(condition, body);
return(node);
}
public static ForLoopStaNode Parse(TokenString tStr, ref int index)
{
int startIndex = index;
if (!tStr.Match(index, TokenType.forStatement, TokenType.rBraceOpen))
{
return(null);
}
index++;
var forDef = tStr.GetRangeInBrackets(ref index).Split(false, TokenType.lineEnd);
if (forDef.Count != 3)
{
index = startIndex;
return(null);
}
VariableDefExpNode declarations = Exp.Parse(forDef[0]) as VariableDefExpNode;
ExpressionNode condition = Exp.Parse(forDef[1]);
if (condition == null)
{
index = startIndex;
return(null);
}
StatementNode body = Sta.Parse(tStr, ref index);
ForLoopStaNode node = new ForLoopStaNode(declarations, condition, body);
var exps = forDef[2].Split(false, TokenType.comma);
foreach (var exp in exps)
{
node.AddExpression(Exp.Parse(exp));
}
return(node);
}
