@Override
public Token parse() {
Token next = first.getNext();
if (!next.isOperator(Operator.BRACKET_LEFT))
throw new RuntimeException("Expected '(' after WHILE, found: " + next);
next = next.getNext();
testExp = new BooleanExpression(next, scope);
next = testExp.parse();
if (!next.isOperator(Operator.BRACKET_RIGHT))
throw new RuntimeException("Expected ')' after WHILE condition, found: " + next);
next = next.getNext();
if (!next.isNewline()) throw new RuntimeException("Expected newline, found: " + next);
next = next.getNext();
Keyword[] target = {Keyword.END};
statements = new StatementGroup(next, target, scope);
next = statements.parse();
return next.getNext();
}
@Override
public void print(int level) {
printLevel(level);
printLn("WHILE");
testExp.print(level + 1);
printLevel(level);
printLn("DO");
statements.print(level + 1);
}
@Override
public void emitCode(GluonOutput code) {
// Creae labels
String labelStart = GluonLabels.createLabel(first, "start");
String labelEnd = GluonLabels.createLabel(first, "end");
GluonLabels.addEndLabel(labelEnd);
code.comment("While Statement");
code.label(labelStart);
testExp.emitCode(code);
code.code("TEST AL, AL ;EAX, EAX");
code.code("JZ " + labelEnd);
statements.emitCode(code);
code.code("JMP " + labelStart);
code.label(labelEnd);
code.comment("End While");
GluonLabels.removeEndLabel(labelEnd);
}
