bpsm / edn-java-guava

extends edn-java to produce immutable Guava collections

edn-java-guava

edn-java-guava provides a solution for parsing edn collections as immutable Guava collections, which have a smaller memory overhead per instance than the standard mutable Java collections.

Installation

This is a Maven project with the following coordinates:

<dependency>
  <groupId>us.bpsm</groupId>
  <artifactId>edn-java-guava</artifactId>
  <version>0.1.0-SNAPSHOT</version>
</dependency>

It depends on edn-java.

Usage

package us.bpsm.edn.guava.examples;

import static org.junit.Assert.*;
import java.util.RandomAccess;
import org.junit.Test;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import us.bpsm.edn.guava.EdnJavaGuava;
import us.bpsm.edn.parser.Parseable;
import us.bpsm.edn.parser.Parser;
import us.bpsm.edn.parser.Parsers;

public class UsageTest {
    @Test
    public void test() {
        Parser p = Parsers.newParser(EdnJavaGuava.defaultConfiguration());
        Parseable r = Parsers.newParseable("{:a 1} #{0} [2] (3)");

        Object o = p.nextValue(r);
        assertTrue(o instanceof ImmutableMap);

        o = p.nextValue(r);
        assertTrue(o instanceof ImmutableSet);

        o = p.nextValue(r);
        assertTrue(o instanceof ImmutableList);
        assertTrue(o instanceof RandomAccess);

        o = p.nextValue(r);
        assertTrue(o instanceof ImmutableList);
    }
}

EdnJavaGuava.defaultConfiguration() is a just a convenient alternative to calling EdnJavaGuava.newParserConfigBuilder().build(). Explicitly constructing the configuration builder gives you the option of adding further customizaitons before creating the Parser.Config.

Current Limitations

• nil values and keys are not supported in any collection type.
• Lists will print back as vectors.