public FormalArgs Parse(TokenStream stream)
{
// Skip parentheses start.
stream.Skip(TokenType.SymbolParenthesesL);
// Create the formal args entity.
var args = new FormalArgs();
// Create the loop buffer token.
Token peekBuffer = stream.Peek();
// Loop until parentheses end.
while (peekBuffer.Type != TokenType.SymbolParenthesesR)
{
// Continuous arguments.
if (!args.Continuous && peekBuffer.Type == TokenType.SymbolContinuous)
{
// Set the continuous flag.
args.Continuous = true;
// Advance stream immediatly.
peekBuffer = stream.Next(TokenType.SymbolParenthesesR);
continue;
}
// Continuous arguments must be final.
else if (args.Continuous)
{
throw new Exception("Unexpected token after continuous arguments");
}
// Invoke the arg parser.
FormalArg arg = new FormalArgParser().Parse(stream);
// Update the buffer.
peekBuffer = stream.Peek();
// Ensure next token is valid.
if (peekBuffer.Type != TokenType.SymbolComma && peekBuffer.Type != TokenType.SymbolParenthesesR)
{
throw new Exception(
$"Unexpected token of type '{peekBuffer.Type}'; Expected comma or parentheses end in argument list");
}
// Skip comma.
else if (peekBuffer.Type == TokenType.SymbolComma)
{
stream.Skip();
}
// Append the parsed arg.
args.Values.Add(arg);
}
// Skip parentheses end if applicable.
if (peekBuffer.Type == TokenType.SymbolParenthesesR)
{
stream.Skip(TokenType.SymbolParenthesesR);
}
// Finish process.
return(args);
}
public FormalArgs Parse(ParserContext context)
{
// Ensure position.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesL);
// Skip parentheses start.
context.Stream.Skip();
// Create the formal args entity.
FormalArgs args = new FormalArgs();
// Create the loop buffer token.
Token buffer = context.Stream.Current;
// Loop until parentheses end.
while (buffer.Type != TokenType.SymbolParenthesesR)
{
// Continuous arguments.
if (!args.Continuous && buffer.Type == TokenType.SymbolContinuous)
{
// Set the continuous flag.
args.Continuous = true;
// Advance stream immediatly.
buffer = context.Stream.Next(TokenType.SymbolParenthesesR);
// Continue loop.
continue;
}
// Continuous arguments must be final.
else if (args.Continuous)
{
throw new Exception("Unexpected token after continuous arguments");
}
// Invoke the arg parser.
FormalArg arg = new FormalArgParser().Parse(context);
// Update the buffer.
buffer = context.Stream.Current;
// Ensure next token is valid.
if (buffer.Type != TokenType.SymbolComma && buffer.Type != TokenType.SymbolParenthesesR)
{
throw new Exception($"Unexpected token of type '{buffer.Type}'; Expected comma or parentheses end in argument list");
}
// Skip the comma token.
else if (buffer.Type == TokenType.SymbolComma)
{
context.Stream.Skip();
// Make sure to update the buffer after skipping the comma token.
buffer = context.Stream.Current;
}
// Append the parsed argument.
args.Values.Add(arg);
}
// Ensure current token is parentheses end.
context.Stream.EnsureCurrent(TokenType.SymbolParenthesesR);
// Skip parentheses end token.
context.Stream.Skip();
// Finish process.
return(args);
}
