private void program(SymbolTable sym) throws ParseException {
start("program");
while (lex.tokenCategory() != Lexer.endOfInput) {
declaration(sym);
if (lex.match(";")) lex.nextLex();
else throw new ParseException(18);
}
stop("program");
}
public void parse() throws ParseException {
sym = new GlobalSymbolTable();
sym.enterType("int", PrimitiveType.IntegerType);
sym.enterType("real", PrimitiveType.RealType);
sym.enterFunction("printInt", new FunctionType(PrimitiveType.VoidType));
sym.enterFunction("printReal", new FunctionType(PrimitiveType.VoidType));
sym.enterFunction("printStr", new FunctionType(PrimitiveType.VoidType));
lex.nextLex();
program(sym);
if (lex.tokenCategory() != lex.endOfInput) parseError(3); // expecting end of file
}
private Type type(SymbolTable sym) throws ParseException {
start("type");
Type result = null;
if (lex.isIdentifier()) {
result = sym.lookupType(lex.tokenText());
lex.nextLex(); // we are a terminal, so call nextLex to setup next state
} else if (lex.match("^")) {
lex.nextLex();
result = new PointerType(type(sym));
} else if (lex.match("[")) {
lex.nextLex();
if (lex.tokenCategory() != Lexer.intToken)
throw new ParseException(32); // expected an integer
int lower = (new Integer(lex.tokenText()).intValue());
lex.nextLex();
if (!lex.match(":")) throw new ParseException(19); // needed to see :
lex.nextLex();
if (lex.tokenCategory() != Lexer.intToken)
throw new ParseException(32); // expected an integer
int upper = (new Integer(lex.tokenText()).intValue());
lex.nextLex();
if (!lex.match("]")) throw new ParseException(24); // should have seen ]
lex.nextLex();
result = sym.lookupType(lex.tokenText());
// type(sym); //might use this instead of nextLex();
// gotta advance so we are at next token
lex.nextLex();
result = new ArrayType(lower, upper, result);
} else {
throw new ParseException(30); // we expected a type name
}
stop("type");
return result;
}
private void constantDeclaration(SymbolTable sym) throws ParseException {
start("constantDeclaration");
if (!lex.match("const")) throw new ParseException(6);
lex.nextLex();
if (!lex.isIdentifier()) throw new ParseException(27);
lex.nextLex();
if (!lex.match("="))
throw new ParseException(
20); // TODO: i think this is the wrong exception. check againset buds using test100
lex.nextLex();
int tid = lex.tokenCategory();
if (tid != Lexer.stringToken || tid != Lexer.realToken || tid != Lexer.intToken)
throw new ParseException(31);
lex.nextLex();
if (sym.nameDefined(lex.tokenText())) throw new ParseException(35, lex.tokenText());
// TODO enterConstant
stop("constantDeclaration");
}
private void parameterList(SymbolTable sym) throws ParseException {
start("parameterList");
int tid = lex.tokenCategory();
if (lex.match("not")
|| lex.match("new")
|| lex.match("(")
|| lex.match("-")
|| lex.match("&")
|| lex.isIdentifier()
|| tid == Lexer.realToken
|| tid == Lexer.intToken
|| tid == Lexer.stringToken) {
expression(sym);
while (lex.match(",")) {
lex.nextLex();
expression(sym);
}
}
stop("parameterList");
}
private void term(SymbolTable sym) throws ParseException {
start("term");
int tid = lex.tokenCategory();
if (lex.match("(")) {
lex.nextLex();
expression(sym);
if (!lex.match(")")) throw new ParseException(22);
lex.nextLex();
} else if (lex.match("not")) {
lex.nextLex();
term(sym);
} else if (lex.match("new")) {
lex.nextLex();
type(sym);
} else if (lex.match("-")) {
lex.nextLex();
term(sym);
} else if (lex.match("&")) {
lex.nextLex();
reference(sym);
} else if (lex.isIdentifier()) {
reference(sym);
if (lex.match("(")) {
lex.nextLex();
parameterList(sym);
if (!lex.match(")")) throw new ParseException(22);
lex.nextLex();
}
} else if (tid == Lexer.intToken || tid == Lexer.realToken || tid == Lexer.stringToken) {
lex.nextLex();
} else {
throw new ParseException(33); // TODO: is this right?!?!
}
stop("term");
}
