public bool ParseStep(SyntaxTreeBuilder pSyntaxTreeBuilder)
{
if (pSyntaxTreeBuilder.ParseNode_Cur == null)
{
return(false);
}
var token = pSyntaxTreeBuilder.TokenScanner.Current;
if (pSyntaxTreeBuilder.ErrorMessage == null)
{
while (pSyntaxTreeBuilder.ParseNode_Cur != null)
{
pSyntaxTreeBuilder.ParseNode_Cur = pSyntaxTreeBuilder.ParseNode_Cur.Parse(pSyntaxTreeBuilder);
if (pSyntaxTreeBuilder.ErrorMessage != null || token != pSyntaxTreeBuilder.TokenScanner.Current)
{
break;
}
}
if (pSyntaxTreeBuilder.ErrorMessage == null && token != pSyntaxTreeBuilder.TokenScanner.Current)
{
pSyntaxTreeBuilder.SyntaxRule_Err = pSyntaxTreeBuilder.SyntaxRule_Cur;
pSyntaxTreeBuilder.ParseNode_Err = pSyntaxTreeBuilder.ParseNode_Cur;
}
}
if (pSyntaxTreeBuilder.ErrorMessage != null)
{
if (token.tokenKind == LexerToken.Kind.EOF)
{
return(false);
}
var missingParseTreeNode = pSyntaxTreeBuilder.SyntaxRule_Cur;
var missingParseNode = pSyntaxTreeBuilder.ParseNode_Cur;
pSyntaxTreeBuilder.SyntaxRule_Cur = pSyntaxTreeBuilder.SyntaxRule_Err;
pSyntaxTreeBuilder.ParseNode_Cur = pSyntaxTreeBuilder.ParseNode_Err;
if (pSyntaxTreeBuilder.SyntaxRule_Cur != null)
{
var cpt = pSyntaxTreeBuilder.SyntaxRule_Cur;
for (var i = cpt.NumValidNodes; i > 0 && !cpt.ChildAt(--i).HasLeafs();)
{
cpt.InvalidateFrom(i);
}
}
if (pSyntaxTreeBuilder.ParseNode_Cur != null)
{
int numSkipped;
pSyntaxTreeBuilder.ParseNode_Cur = pSyntaxTreeBuilder.ParseNode_Cur.Recover(pSyntaxTreeBuilder, out numSkipped);
}
if (pSyntaxTreeBuilder.ParseNode_Cur == null)
{
if (token.m_kLinkedLeaf != null)
{
token.m_kLinkedLeaf.ReparseToken();
}
new SyntaxTreeNode_Leaf(pSyntaxTreeBuilder.TokenScanner);
if (cachedErrorParseNode == pSyntaxTreeBuilder.ParseNode_Err)
{
token.m_kLinkedLeaf.m_sSyntaxError = cachedErrorMessage;
}
else
{
token.m_kLinkedLeaf.m_sSyntaxError = "Unexpected token! Expected " + pSyntaxTreeBuilder.ParseNode_Err.FirstSet.ToString(this);
cachedErrorMessage = token.m_kLinkedLeaf.m_sSyntaxError;
cachedErrorParseNode = pSyntaxTreeBuilder.ParseNode_Err;
}
pSyntaxTreeBuilder.ParseNode_Cur = pSyntaxTreeBuilder.ParseNode_Err;
pSyntaxTreeBuilder.SyntaxRule_Cur = pSyntaxTreeBuilder.SyntaxRule_Err;
if (!pSyntaxTreeBuilder.TokenScanner.MoveNext())
{
return(false);
}
pSyntaxTreeBuilder.ErrorMessage = null;
}
else
{
if (missingParseNode != null && missingParseTreeNode != null)
{
pSyntaxTreeBuilder.SyntaxRule_Cur = missingParseTreeNode;
pSyntaxTreeBuilder.ParseNode_Cur = missingParseNode;
}
pSyntaxTreeBuilder.InsertMissingToken(pSyntaxTreeBuilder.ErrorMessage
?? ("Expected " + missingParseNode.FirstSet.ToString(this)));
if (missingParseNode != null && missingParseTreeNode != null)
{
pSyntaxTreeBuilder.ErrorMessage = null;
pSyntaxTreeBuilder.ErrorToken = null;
pSyntaxTreeBuilder.SyntaxRule_Cur = missingParseTreeNode;
pSyntaxTreeBuilder.ParseNode_Cur = missingParseNode;
pSyntaxTreeBuilder.ParseNode_Cur = missingParseNode.parent.NextAfterChild(missingParseNode, pSyntaxTreeBuilder);
}
pSyntaxTreeBuilder.ErrorMessage = null;
pSyntaxTreeBuilder.ErrorToken = null;
}
}
return(true);
}
