MultiplyFactor.java

package jscl.text;

import jscl.math.Generic;
import jscl.text.msg.Messages;

import javax.annotation.Nonnull;

/**
 * User: serso
 * Date: 10/27/11
 * Time: 2:45 PM
 */
class MultiplyFactor implements Parser<Generic> {

    public static final Parser<Generic> parser = new MultiplyFactor();

    static boolean isMultiplication(char c) {
        return c == '*' || c == '×' || c == '∙';
    }

    public Generic parse(@Nonnull Parameters p, Generic previousSumElement) throws ParseException {
        final int pos0 = p.position.intValue();

        ParserUtils.skipWhitespaces(p);
        final int pos1 = p.position.intValue();
        if (pos1 < p.expression.length() && isMultiplication(p.expression.charAt(pos1))) {
            p.position.increment();
        } else {
            ParserUtils.throwParseException(p, pos0, Messages.msg_10, '*', '/');
        }

        return ParserUtils.parseWithRollback(Factor.parser, pos0, previousSumElement, p);
    }
}