package jscl.text;
import jscl.math.Generic;
import jscl.text.msg.Messages;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import static jscl.text.MultiplyFactor.isMultiplication;
/**
* User: serso
* Date: 10/27/11
* Time: 2:45 PM
*/
class PowerParser implements Parser<Void> {
public static final Parser<Void> parser = new PowerParser();
private PowerParser() {
}
@Nullable
public Void parse(@Nonnull Parameters p, Generic previousSumElement) throws ParseException {
int pos0 = p.position.intValue();
ParserUtils.skipWhitespaces(p);
if (p.position.intValue() < p.expression.length() && p.expression.charAt(p.position.intValue()) == '^') {
p.position.increment();
} else {
if (isDoubleStar(p.expression, p.position.intValue())) {
p.position.increment();
p.position.increment();
} else {
ParserUtils.throwParseException(p, pos0, Messages.msg_10, '^', "**");
}
}
return null;
}
private boolean isDoubleStar(@Nonnull String string, int position) {
return position + 1 < string.length() && isMultiplication(string.charAt(position)) && isMultiplication(string.charAt(position + 1));
}
}