UnitizedDoubleArrayParser.java

package org.andork.unit;

import java.text.CharacterIterator;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.function.ToDoubleFunction;

import org.andork.func.CharPredicate;

public class UnitizedDoubleArrayParser<T extends UnitType<T>>
		implements Function<CharacterIterator, UnitizedDoubleArray<T>> {
	ToDoubleFunction<CharacterIterator> doubleParser;
	CharPredicate isDelimiter;
	Function<CharacterIterator, Unit<T>> unitParser;
	Supplier<Unit<T>> defaultUnit;

	public UnitizedDoubleArrayParser(ToDoubleFunction<CharacterIterator> doubleParser, CharPredicate isDelimiter,
			Function<CharacterIterator, Unit<T>> unitParser, Supplier<Unit<T>> defaultUnit) {
		super();
		this.doubleParser = doubleParser;
		this.isDelimiter = isDelimiter;
		this.unitParser = unitParser;
		this.defaultUnit = defaultUnit;
	}

	@Override
	public UnitizedDoubleArray<T> apply(CharacterIterator t) {
		List<Double> values = new ArrayList<Double>();

		while (true) {
			int lastStart = t.getIndex();
			double value = doubleParser.applyAsDouble(t);
			if (Double.isNaN(value)) {
				t.setIndex(lastStart);
				break;
			}
			values.add(value);

			char c = t.current();
			while (Character.isWhitespace(c)) {
				c = t.next();
			}

			if (isDelimiter.test(c)) {
				c = t.next();
				while (Character.isWhitespace(c)) {
					c = t.next();
				}
			}
		}

		if (values.isEmpty()) {
			return null;
		}

		Unit<T> unit = unitParser.apply(t);
		if (unit == null) {
			unit = defaultUnit.get();
		}

		UnitizedDoubleArray<T> result = new UnitizedDoubleArray<>(values.size(), unit);
		int k = 0;
		for (Double value : values) {
			result.set(k++, value, unit);
		}

		return result;
	}
}