/// <summary>
/// Parse the specified parser.
/// </summary>
/// <param name="parser">Parser.</param>
public static AstNode Parse(Parser parser)
{
CodeBlockNode block = new CodeBlockNode();
while (!parser.EndOfStream)
block.Children.Add(StatementNode.Parse(parser));
return block;
}
private static AstNode parseTerm(Parser parser)
{
if (parser.MatchToken(TokenType.Number))
return new NumberNode(Convert.ToDouble(parser.ExpectToken(TokenType.Number).Value));
else if (parser.AcceptToken(TokenType.Parentheses, "("))
{
AstNode statement = ExpressionNode.Parse(parser);
parser.ExpectToken(TokenType.Parentheses, ")");
return statement;
}
else if (parser.MatchToken(TokenType.Identifier, "Then"))
{
CodeBlockNode block = new CodeBlockNode();
parser.ExpectToken(TokenType.Identifier, "Then");
while (!parser.EndOfStream && !parser.MatchToken(TokenType.Identifier, "EndIf") && !parser.MatchToken(TokenType.Identifier, "Else"))
block.Children.Add(StatementNode.Parse(parser));
if (parser.MatchToken(TokenType.Identifier, "Else"))
return block;
parser.ExpectToken(TokenType.Identifier, "EndIf");
return block;
}
else if (parser.MatchToken(TokenType.Identifier, "Else"))
{
parser.ExpectToken(TokenType.Identifier, "Else");
return StatementNode.Parse(parser);
}
else if (parser.MatchToken(TokenType.Identifier, "Do"))
{
CodeBlockNode block = new CodeBlockNode();
parser.ExpectToken(TokenType.Identifier, "Do");
while (!parser.EndOfStream && !parser.MatchToken(TokenType.Identifier, "End"))
block.Children.Add(StatementNode.Parse(parser));
parser.ExpectToken(TokenType.Identifier, "End");
return block;
}
else if (parser.MatchToken(TokenType.String))
return new StringNode((string)parser.ExpectToken(TokenType.String).Value);
else if (parser.MatchToken(TokenType.Identifier))
return new IdentifierNode((string)parser.ExpectToken(TokenType.Identifier).Value);
else
throw new Exception("Unexpected " + parser.CurrentToken().TokenType + " in Parser: " + parser.CurrentToken().Value + ".");
}
/// <summary>
/// Parse this instance.
/// </summary>
public AstNode Parse()
{
CodeBlockNode tree = new CodeBlockNode();
while (!EndOfStream)
tree.Children.Add(StatementNode.Parse(this));
return tree;
}