public Expr OnParseWhile()
{
var tokenIt = this._parser.TokenIt;
var initiatorToken = tokenIt.NextToken;
var expr = new WhileExpr();
// <codeWhile>
tokenIt.Expect(Tokens.While);
ParseConditionalBlock(expr);
// </codeWhile>
this._parser.SetupContext(expr, initiatorToken);
return expr;
}
/// <summary>
/// Execute
/// </summary>
public object VisitWhile(WhileExpr expr)
{
expr.DoContinueRunning = true;
expr.DoBreakLoop = false;
expr.DoContinueLoop = false;
var result = expr.Condition.Evaluate(this) as LObject;
expr.DoContinueRunning = EvalHelper.IsTrue(result);
while (expr.DoContinueRunning)
{
if (expr.Statements != null && expr.Statements.Count > 0)
{
foreach (var stmt in expr.Statements)
{
stmt.Evaluate(this);
this.Ctx.Limits.CheckLoop(expr);
// If Break statment executed.
if (expr.DoBreakLoop)
{
expr.DoContinueRunning = false;
break;
}
// Continue statement.
else if (expr.DoContinueLoop)
break;
}
}
else break;
// Break loop here.
if (expr.DoContinueRunning == false)
break;
result = expr.Condition.Evaluate(this) as LObject;
expr.DoContinueRunning = EvalHelper.IsTrue(result);
}
return LObjects.Null;
}
/// <summary>
/// Visits the while statement tree.
/// </summary>
/// <param name="whileExpr"></param>
public object VisitWhile(WhileExpr expr)
{
_callBackOnNodeStart(expr);
expr.Condition.Visit(this);
foreach (var stmt in expr.Statements)
{
stmt.Visit(this);
}
return null;
}
