public exprAST parseExpr()
{
listAddopTermAST temp = null;
listAddopTermAST result = null;
termAST term = null;
addopAST addop = null;
termAST term2 = null;
//Expr = [ "-" ] Term { Addop Term }
Boolean ind = false;
Boolean ind2 = false;
if (currentToken.sym == sym.RES)
{
acceptIt();
ind = true;
}
term = parseTerm();
while (currentToken.sym == sym.SUM || currentToken.sym == sym.RES)
{
if (ind2 == false)
{
addop = parseAddop();
term2 = parseTerm();
result = new unAddopTermAST(addop, term2);
ind2 = true;
}
else
{
addop = parseAddop();
term2 = parseTerm();
temp = new unAddopTermAST(addop, term2);
result = new varAddopTermAST(result, temp);
}
}
if (ind == false && result == null)
{
return(new expreSoloTermAST(term));
}
else if (ind == true && result == null)
{
return(new exprNegativaTermAST(term));
}
else if (ind == false && result != null)
{
return(new exprAddopTermAST(term, result));
}
else if (ind == true && result != null)
{
return(new exprNegativaAddopTermAST(result, term));
}
return(null);
}
public exprAddopTermAST(termAST t, listAddopTermAST l)
{
listAddopTerm = l;
term = t;
}
public varAddopTermAST(listAddopTermAST hh1, listAddopTermAST hh2)
{
h1 = hh1;
h1 = hh2;
}
public exprNegativaAddopTermAST(listAddopTermAST l, termAST t)
{
listAddopTerm = l;
term = t;
}
public exprNegativaAddopTermAST(listAddopTermAST l, termAST t)
{
listAddopTerm = l;
term = t;
}
