public static AbstractSyntaxTree Parse(Token[] stream)
{
Queue <Token> tokens = new Queue <Token>(stream);
AST.Function main = ParseFunction(tokens);
AST.Program program = new AST.Program(main);
AbstractSyntaxTree ast = new AbstractSyntaxTree(program);
return(ast);
}
public static AST.Function ParseFunction(Queue <Token> tokens)
{
Token token = tokens.Dequeue();
if (!Match(token, Token.TokenType.Keyword, Syntax.GetKeyword(Syntax.Keyword.Integer)))
{
Fail(token);
}
token = tokens.Dequeue();
if (token.Type != Token.TokenType.Identifier)
{
Fail(token);
}
string identifier = token.Value;
token = tokens.Dequeue();
if (token.Type != Token.TokenType.OpenParenthesis)
{
Fail(token);
}
token = tokens.Dequeue();
if (token.Type != Token.TokenType.CloseParenthesis)
{
Fail(token);
}
token = tokens.Dequeue();
if (token.Type != Token.TokenType.OpenBrace)
{
Fail(token);
}
AST.Function function = new AST.Function(identifier, ParseStatement(tokens));
token = tokens.Dequeue();
if (token.Type != Token.TokenType.CloseBrace)
{
Fail(token);
}
return(function);
}
static void WriteFunction(StreamWriter writer, AST.Function function)
{
writer.Write(Assembly.format_function, function.Identifier);
WriteStatement(writer, function.Body);
}