public IEnumerable <Token <R> > ReadToScopeClose(R open, R close, Brackets bracketPairs)
{
SkipSpace();
_stack.Clear();
Token <R> token = null;
while (!End)
{
token = ReadToken();
if (bracketPairs.ContainsOpening(token.ID) || open == token.ID) // Allows nesting
{
_stack.Push(token);
}
else if (bracketPairs.ContainsClosing(token.ID) || token.ID == close) // Allows nesting
{
// Since this method assumes that the first opening bracket was already read, an empty _stack indicates main scope closure.
if (!_stack.Any() && token.ID == close)
{
yield break;
}
var lastOpening = _stack.Pop();
if (!bracketPairs.Contains(lastOpening.ID, token.ID))
{
throw new RantException(_source, token,
"Invalid closure '"
+ lastOpening.Value
+ " ... "
+ token.Value
+ "' - expected '"
+ RantLexer.Rules.GetSymbolForId(bracketPairs.GetClosing(lastOpening.ID))
+ "'");
}
}
yield return(token);
}
throw new RantException(_source, null, "Unexpected end of file - expected '" + RantLexer.Rules.GetSymbolForId(close) + "'.");
}
public IEnumerable <IEnumerable <Token <R> > > ReadMultiItemScope(R open, R close, R separator, Brackets bracketPairs)
{
SkipSpace();
_stack.Clear();
// Assumes first bracket was already read.
_stack.Push(new Token <R>(open, RantLexer.Rules.GetSymbolForId(open)));
int start = _pos;
Token <R> token = null;
while (!End)
{
// Peek but don't consume - this saves some calculations later on.
token = PeekToken();
// Opening bracket
if (bracketPairs.ContainsOpening(token.ID) || open == token.ID) // Previous bracket allows nesting
{
_stack.Push(token);
}
// Closing bracket
else if (bracketPairs.ContainsClosing(token.ID) || close == token.ID) // Previous bracket allows nesting
{
var lastOpening = _stack.Pop();
// Handle invalid closures
if (!bracketPairs.Contains(lastOpening.ID, token.ID)) // Not in main pair
{
throw new RantException(_source, token,
"Invalid closure '"
+ lastOpening.Value
+ " ... "
+ token.Value
+ "' - expected '"
+ RantLexer.Rules.GetSymbolForId(bracketPairs.GetClosing(lastOpening.ID))
+ "'");
}
// If the _stack is empty, this is the last item. Stop the iterator.
if (!_stack.Any())
{
yield return(_tokens
.SkipWhile((t, i) => i < start) // Cut to start of section
.TakeWhile((t, i) => i < _pos - start) // Cut to end of section
.SkipWhile(t => t.ID == R.Whitespace) // Remove leading whitespace
.Reverse() // Reverse to trim end
.SkipWhile(t => t.ID == R.Whitespace) // Remove trailing whitespace
.Reverse() // Reverse back
.ToArray());
_pos++;
yield break;
}
}
// Separator
else if (token.ID == separator && _stack.Count == 1)
{
yield return(_tokens
.SkipWhile((t, i) => i < start) // Cut to start of section
.TakeWhile((t, i) => i < _pos - start) // Cut to end of section
.SkipWhile(t => t.ID == R.Whitespace) // Remove leading whitespace
.Reverse() // Reverse to trim end
.SkipWhile(t => t.ID == R.Whitespace) // Remove trailing whitespace
.Reverse() // Reverse back
.ToArray());
_pos++;
start = _pos;
continue;
}
// Move to next position
_pos++;
}
throw new RantException(_source, null, "Unexpected end of file - expected '" + RantLexer.Rules.GetSymbolForId(close) + "'.");
}