ListDeserialiser.java

package com.codepoetics.octarine.json.deserialisation;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import org.pcollections.PVector;
import org.pcollections.TreePVector;

import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.function.Function;

public final class ListDeserialiser<V> implements SafeDeserialiser<PVector<V>> {

    public static <V> ListDeserialiser<V> readingItemsWith(Function<JsonParser, ? extends V> itemDeserialiser) {
        return new ListDeserialiser<>(itemDeserialiser);
    }

    public static ListDeserialiser<String> readingStrings() {
        return readingItemsWith(Deserialisers.ofString);
    }

    public static ListDeserialiser<Integer> readingIntegers() {
        return readingItemsWith(Deserialisers.ofInteger);
    }

    public static ListDeserialiser<Long> readingLongs() {
        return readingItemsWith(Deserialisers.ofLong);
    }

    public static ListDeserialiser<Double> readingDoubles() {
        return readingItemsWith(Deserialisers.ofDouble);
    }

    public static ListDeserialiser<Boolean> readingBooleans() {
        return readingItemsWith(Deserialisers.ofBoolean);
    }

    private final Function<JsonParser, ? extends V> itemDeserialiser;

    private ListDeserialiser(Function<JsonParser, ? extends V> itemDeserialiser) {
        this.itemDeserialiser = itemDeserialiser;
    }

    @Override
    public PVector<V> applyUnsafe(JsonParser p) throws IOException {
        List<V> values = new LinkedList<>();
        while (p.nextToken() != JsonToken.END_ARRAY) {
            values.add(itemDeserialiser.apply(p));
        }
        return TreePVector.from(values);
    }
}