ParameterListParser.java

package jscl.text;

import jscl.math.Generic;
import jscl.util.ArrayUtils;

import javax.annotation.Nonnull;
import java.util.ArrayList;
import java.util.List;

public class ParameterListParser implements Parser<Generic[]> {

    public static final Parser<Generic[]> parser1 = new ParameterListParser();
    private final int minNumberOfParameters;

    private ParameterListParser() {
        this.minNumberOfParameters = 1;
    }

    public ParameterListParser(int minNumberOfParameters) {
        this.minNumberOfParameters = minNumberOfParameters;
    }

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

        final List<Generic> result = new ArrayList<Generic>();

        ParserUtils.tryToParse(p, pos0, '(');

        try {
            result.add(ExpressionParser.parser.parse(p, previousSumElement));
        } catch (ParseException e) {
            if (minNumberOfParameters > 0) {
                p.position.setValue(pos0);
                throw e;
            } else {
                p.exceptionsPool.release(e);
            }
        }

        while (true) {
            try {
                result.add(CommaAndExpression.parser.parse(p, previousSumElement));
            } catch (ParseException e) {
                p.exceptionsPool.release(e);
                break;
            }
        }

        ParserUtils.tryToParse(p, pos0, ')');


        return ArrayUtils.toArray(result, new Generic[result.size()]);
    }
}