/// <summary>
/// Parses a token stream creating the largest statement possible
/// </summary>
/// <param name="stream">Stream of tokens to parse</param>
/// <returns>Statement</returns>
private StatementList ParseStatement(Stream stream)
{
var tokenType = stream.Peek().Type;
Token identifier = null;
switch (tokenType)
{
case TokenType.Identifier:
//standard identifier
identifier = stream.Next();
break;
case TokenType.OpenBracket:
case TokenType.OpenParenthesis:
//ignore these
break;
case TokenType.StringLiteral:
case TokenType.MultiLineStringLiteral:
case TokenType.StringLiteralPipe:
case TokenType.QuotedStringLiteral:
//string statement
identifier = stream.Next();
break;
}
Statement statement = null;
StatementTail tail = null;
while (stream.Peek() != null)
{
var token = stream.Peek();
if (token == null)
{
break;
}
switch (token.Type)
{
case TokenType.OpenParenthesis:
case TokenType.OpenBrace:
case TokenType.OpenBracket:
tail = ParseStatementTail(stream);
break;
case TokenType.GreaterThan:
//consume greater than
stream.NextNoReturn();
//might be a single child or a statement list of siblings
tail = ParseSingleStatementTail(stream);
break;
case TokenType.Colon:
//next thing must be an identifier
var colon = stream.Next();
identifier = stream.Next();
statement = new EncodedOutput(_host, identifier.Content);
goto checkForSiblings;
case TokenType.Equal:
//next thing must be an identifier
var equal = stream.Next();
identifier = stream.Next();
statement = new RawOutput(_host, identifier.Content);
goto checkForSiblings;
default:
statement = GetStatementFromToken(identifier, tail);
goto checkForSiblings;
}
}
statement = GetStatementFromToken(identifier, tail);
checkForSiblings:
var list = new StatementList(_host);
list.Add(statement);
while (stream.Peek() != null)
{
//Parrot.Debugger.Debug.WriteLine("Looking for siblings");
if (stream.Peek().Type == TokenType.Plus)
{
//it's now a statementlist not a statement
stream.NextNoReturn();
var siblings = ParseStatement(stream);
foreach (var sibling in siblings)
{
list.Add(sibling);
}
}
else
{
break;
}
}
return list;
}
/// <summary>
/// Parses a token stream creating the largest statement possible
/// </summary>
/// <param name="stream">Stream of tokens to parse</param>
/// <returns>Statement</returns>
private StatementList ParseStatement(Stream stream)
{
var tokenType = stream.Peek().Type;
Token identifier = null;
switch (tokenType)
{
case TokenType.Identifier:
//standard identifier
identifier = stream.Next();
break;
case TokenType.OpenBracket:
case TokenType.OpenParenthesis:
//ignore these
break;
case TokenType.StringLiteral:
case TokenType.MultiLineStringLiteral:
case TokenType.StringLiteralPipe:
case TokenType.QuotedStringLiteral:
//string statement
identifier = stream.Next();
break;
}
Statement statement = null;
StatementTail tail = null;
while (stream.Peek() != null)
{
var token = stream.Peek();
if (token == null)
{
break;
}
switch (token.Type)
{
case TokenType.OpenParenthesis:
case TokenType.OpenBrace:
case TokenType.OpenBracket:
tail = ParseStatementTail(stream);
break;
case TokenType.GreaterThan:
//consume greater than
stream.NextNoReturn();
//might be a single child or a statement list of siblings
tail = ParseSingleStatementTail(stream);
break;
case TokenType.Colon:
//next thing must be an identifier
var colon = stream.Next();
identifier = stream.Next();
statement = new EncodedOutput(_host, identifier.Content);
goto checkForSiblings;
case TokenType.Equal:
//next thing must be an identifier
var equal = stream.Next();
identifier = stream.Next();
statement = new RawOutput(_host, identifier.Content);
goto checkForSiblings;
default:
statement = GetStatementFromToken(identifier, tail);
goto checkForSiblings;
}
}
statement = GetStatementFromToken(identifier, tail);
checkForSiblings:
var list = new StatementList(_host);
list.Add(statement);
while (stream.Peek() != null)
{
//Parrot.Debugger.Debug.WriteLine("Looking for siblings");
if (stream.Peek().Type == TokenType.Plus)
{
//it's now a statementlist not a statement
stream.NextNoReturn();
var siblings = ParseStatement(stream);
foreach (var sibling in siblings)
{
list.Add(sibling);
}
}
else
{
break;
}
}
return(list);
}
