public void S() throws IOException {
AbstractNode node;
AbstractNode exprn;
Id assId;
if (look.tag == '(' || look.tag == Tag.NUM) {
node = E();
} else if (look.tag == Tag.ID) {
currentAssigneeSymbol = (Id) look;
match(Tag.ID);
if (look.tag == '=') {
match('=');
exprn = E();
node =
threeAddressCodeGenerator.generateCodeForNode(
threeAddressCodeGenerator.insertAndGetLeaf(currentAssigneeSymbol),
exprn,
"="); //// generate code for assignment
} else {
skipId = currentAssigneeSymbol;
currentAssigneeSymbol = null;
skipFlag = 1;
node = E();
}
} else {
throw new Error("Syntax Error");
}
}
public AbstractNode F() throws IOException {
AbstractNode abstractNode = null;
if (look.tag == '(') {
match('(');
abstractNode = E();
match(')');
} else if (look.tag == Tag.ID) {
Id word = (Id) look;
String workLex = word.lexeme;
stackMachine.postfixTokenStack.push(word);
match(Tag.ID);
abstractNode =
threeAddressCodeGenerator.insertAndGetLeaf(
word); // insert leaf to processed symbols if not exists
postFix.append(workLex);
// System.out.print(workLex);
} else if (look.tag == Tag.NUM) {
Num num = (Num) look;
String IntNum = num.tostring();
match(Tag.NUM);
stackMachine.postfixTokenStack.push(num);
abstractNode =
threeAddressCodeGenerator.insertAndGetLeaf(
num); // insert leaf to processed symbols if not exists
postFix.append(IntNum);
// System.out.print(IntNum);
} else if (look.tag == Tag.FLOAT) {
Real real = (Real) look;
String floatNum = real.tostring();
match(Tag.FLOAT);
stackMachine.postfixTokenStack.push(real);
abstractNode =
threeAddressCodeGenerator.insertAndGetLeaf(
real); // insert leaf to processed symbols if not exists
postFix.append(floatNum);
// System.out.print(floatNum);
} else if (skipId != null && skipFlag == 1) {
Id word = (Id) skipId;
String workLex = word.lexeme;
stackMachine.postfixTokenStack.push(word);
match(Tag.ID);
abstractNode =
threeAddressCodeGenerator.insertAndGetLeaf(
word); // insert leaf to processed symbols if not exists
postFix.append(workLex);
skipId = null;
// System.out.print(workLex);
} else {
throw new Error("Syntax Error");
}
return abstractNode;
}
public AbstractNode T1(AbstractNode factnodeinh) throws IOException {
AbstractNode node; // node which rerpesents the operation so far
AbstractNode snode; // synthesised attribute which gives the full answer
AbstractNode prefn = factnodeinh; // previous factor nonterminal is inherited
AbstractNode curfn;
if (look.tag == '*') {
match('*');
curfn = F();
// System.out.print("*");
postFix.append("*");
stackMachine.evaluate("*");
node =
threeAddressCodeGenerator.generateCodeForNode(
prefn, curfn, "*"); // generate code for node
snode = T1(node);
} else {
snode = factnodeinh;
}
return snode;
}