public Statement Parse()
{
// the Game Maker lexer runs before parsing, but we will scan as we are parsing, using l.Scan(),
// implemented in move() and peek(). We will, as in Game Maker, parse completely before executing,
// to catch all compile errors. I've heard Game Maker compiles to byte code, but we will build
// a parse tree of Stmts and Exprs. We return a Stmt node that can be executed by Stmt.Exec().
// Game Maker does all of its parsing during loading, and if there are no errors, caches the
// intermediate representation, which is referenced by the events and scripts.
Statement s;
move();
if (t == TokenKind.OpeningCurlyBrace)
{
s = block(); if (t != TokenKind.Eof) error(Error.ProgramEnds);
return s;
}
s = Statement.Nop;
while (t != TokenKind.Eof)
{
s = new Sequence(s, stmt(), next.line, next.col); // stmt() throws ProgramError
}
Current = s;
return s;
}
public abstract void VisitSequence(Sequence sequence);
Statement block()
{
Statement s = Statement.Nop;
int l = next.line;
int c = next.col;
match(Token.OpeningCurlyBrace);
while (t != TokenKind.ClosingCurlyBrace && t != TokenKind.Eof)
{
s = new Sequence(s, stmt(), l, c);
}
match(Token.ClosingCurlyBrace);
while (t == TokenKind.Semicolon) move();
return s;
}
