private void CheckForStatement(ASTForStatementNode forNode)
{
//check counter
if (forNode.Counter is ASTVariableNode varNode)
{
CheckVariable(varNode);
}
if (forNode.Counter is ASTAssignStatementNode assignNode)
{
CheckAssignStatement(assignNode);
}
//check condition
CheckExpression(forNode.Condition);
CheckImplicitCast(forNode.Condition, typeof(bool));
//check step if his defined
if (forNode.Step != null)
{
CheckExpression(forNode.Step);
CheckImplicitCast(forNode.Step, typeof(decimal));
}
//checkbody
if (forNode.Body != null)
{
_inLoop = true;
CheckBody(forNode.Body);
_inLoop = false;
}
}
/// <summary>
/// Builds for loop statement
/// </summary>
/// <param name="forNode">For loop node</param>
private void BuildForStatement(ASTForStatementNode forNode)
{
var condition = _emitter.DefineLabel();
var exitFor = _emitter.DefineLabel();
ASTVariableNode counter = null;
//init counter if needed
if (forNode.Counter is ASTAssignStatementNode assignNode)
{
BuildStatement(assignNode);
counter = (ASTVariableNode)assignNode.Left;
}
else
{
counter = (ASTVariableNode)forNode.Counter;
}
//check condition
_emitter.MarkLabel(condition);
BuildExpression(forNode.Condition);
_emitter.JumpFalse(exitFor);
//body
_loopsEnds.Push(exitFor);
if (forNode.Body != null)
{
BuildStatement(forNode.Body);
}
_loopsEnds.Pop();
//load counter
BuildExpression(counter);
_emitter.ToDecimal();
//build step
if (forNode.Step != null)
{
BuildExpression(forNode.Step);
if (_emitter.StackPeek() != typeof(decimal))
{
_emitter.ToDecimal();
}
}
else //default step
{
_emitter.PushLong(1);
_emitter.ToDecimal();
}
//update counter
_emitter.StaticCall(typeof(decimal), "Add", new Type[] { typeof(decimal), typeof(decimal) });
_emitter.Box();
Store(counter.Name);
//jump to condition
_emitter.Jump(condition);
//exit
_emitter.MarkLabel(exitFor);
}
private void VisitForStatement(ASTForStatementNode forStmt)
{
if (forStmt.Counter is ASTVariableNode varNode)
{
VisitVariable(varNode);
}
if (forStmt.Counter is ASTAssignStatementNode assignStmt)
{
VisitAssignStatement(assignStmt);
}
if (forStmt.Body != null)
{
VisitBodyStatement(forStmt.Body);
}
}
public override void ExitForStatement([NotNull] CmanParser.ForStatementContext context)
{
ASTBodyStatementNode body = null;
IASTExprNode step = null;
IASTExprNode cond = null;
ASTNode counter = null;
Queue <ASTNode> childs = new Queue <ASTNode>();
while (!(_nodes.Peek() is ASTForStatementNode))
{
childs.Enqueue(_nodes.Pop());
//childs.Push(_nodes.Pop());
}
//has body
if (childs.Peek() is ASTBodyStatementNode)
{
body = (ASTBodyStatementNode)childs.Dequeue();
}
int childCount = childs.Count();
//counter, condition, step
if (childCount == 3)
{
step = (IASTExprNode)childs.Dequeue();
}
cond = (IASTExprNode)childs.Dequeue();
counter = childs.Dequeue();
ASTForStatementNode forNode = (ASTForStatementNode)_nodes.Peek();
forNode.Counter = counter;
forNode.Condition = cond;
forNode.Step = step;
forNode.Body = body;
}
