public override ParseTree Parse(Lexer lexer, ParserState state)
{
state.RuntimeState.Runtime.ParseTrace.Enter(this, lexer.CurrentSource(), "Pattern " + Type.Name);
int start = lexer.Position;
if (state.Excluded.Contains(this))
{
state.RuntimeState.Runtime.ParseTrace.No(this, lexer.CurrentSource(), "Excluded");
return(ParseTree.No);
}
Precedence oldCurrentPrecedence = state.CurrentPrecedence;
if (Precedence.Overwrites(state.CurrentPrecedence))
{
state.CurrentPrecedence = Precedence;
}
ParseTree tree = ParseGraph.Parse(lexer, state);
state.CurrentPrecedence = oldCurrentPrecedence;
if (tree == ParseTree.No)
{
state.RuntimeState.Runtime.ParseTrace.No(this, lexer.SourceFrom(start));
return(ParseTree.No);
}
state.RuntimeState.Runtime.ParseTrace.Yes(this, lexer.SourceFrom(start));
return(tree);
}
public override ParseTree Parse(Lexer lexer, ParserState state)
{
int start = lexer.Position;
state.RuntimeState.Runtime.ParseTrace.Enter(this, lexer.CurrentSource(), "Pattern " + Type.Name);
/*state.RuntimeState.Runtime.ParseTrace.Enter(this, lexer.CurrentSource(), "Excluded:");
*
* foreach (Pattern excluded in state.Excluded)
* state.RuntimeState.Runtime.ParseTrace.Single(excluded.Type.Name);
*
* state.RuntimeState.Runtime.ParseTrace.Leave(this);*/
if (state.Excluded.Contains(this))
{
state.RuntimeState.Runtime.ParseTrace.No(this, lexer.CurrentSource(), "Excluded");
return(ParseTree.No);
}
ParserMemoryKey key = new ParserMemoryKey(this, start);
bool oldSkipMemoryForLeftRecursion = state.SkipMemoryForLeftRecursion;
if (state.SkipMemoryForLeftRecursion)
{
state.SkipMemoryForLeftRecursion = false;
}
else
{
ParserMemoryEntry entry;
if (state.Memory.TryGetValue(key, out entry))
{
state.RuntimeState.Runtime.ParseTrace.LinkNext(entry.Tag);
if (entry.Tree == ParseTree.No)
{
state.RuntimeState.Runtime.ParseTrace.No(this, lexer.SourceFrom(start), "From memory");
}
else
{
state.RuntimeState.Runtime.ParseTrace.Yes(this, lexer.SourceFrom(start), "From memory");
lexer.Position = entry.End;
}
return(entry.Tree);
}
}
ConcretePattern oldRecursionExclude = state.RecursionExclude;
if (RecursionBehaviour != RecursionBehaviour.Recursive)
{
if (state.RecursionExclude != null)
{
state.Excluded.Remove(state.RecursionExclude);
}
state.RecursionExclude = this;
state.Excluded.Add(this);
}
RecursionBehaviour oldRecursionBehaviour = state.RecursionBehaviour;
state.RecursionBehaviour = RecursionBehaviour;
Precedence oldCurrentPrecedence = state.CurrentPrecedence;
if (Precedence.Overwrites(state.CurrentPrecedence))
{
state.CurrentPrecedence = Precedence;
}
bool oldPrecedenceCanEqualCurrent = state.PrecedenceCanEqualCurrent;
state.PrecedenceCanEqualCurrent = RecursionBehaviour == RecursionBehaviour.Recursive;
ParseTree tree = ParseGraph.Parse(lexer, state);
state.CurrentPrecedence = oldCurrentPrecedence;
state.PrecedenceCanEqualCurrent = oldPrecedenceCanEqualCurrent;
state.RecursionBehaviour = oldRecursionBehaviour;
state.RecursionExclude = oldRecursionExclude;
state.SkipMemoryForLeftRecursion = oldSkipMemoryForLeftRecursion;
if (RecursionBehaviour != RecursionBehaviour.Recursive)
{
if (oldRecursionExclude != null)
{
state.Excluded.Add(oldRecursionExclude);
}
state.Excluded.Remove(this);
}
if (tree != ParseTree.No)
{
lexer.Whitespace(state.RuntimeState);
tree = Instantiate(lexer, state, start, tree);
}
object nextTag = new object();
state.RuntimeState.Runtime.ParseTrace.TagNext(nextTag);
if (tree == ParseTree.No)
{
state.RuntimeState.Runtime.ParseTrace.No(this, lexer.SourceFrom(start));
}
else
{
state.RuntimeState.Runtime.ParseTrace.Yes(this, lexer.SourceFrom(start));
if (RecursionBehaviour == RecursionBehaviour.LeftRecursive)
{
tree = LeftRecurse(lexer, state, start, tree);
}
}
// TODO - can remove some other code if not remembering
if (ShouldRemember)
{
state.Memory[key] = new ParserMemoryEntry(tree, lexer.Position, nextTag);
}
return(tree);
}
