Java-OO is a modular extension (plugin) to Java compilers and IDEs for (Scala-like) Operator Overloading support. Works with standard JavaC compiler, Netbeans IDE, Eclipse IDE, IntelliJ IDEA IDE and any build tools.
Example (see other examples at examples/ dir):
import java.math.*;
import java.util.*;
public class Test {
public static void main(String[] args) {
BigInteger a = BigInteger.valueOf(1), // without OO
b = 2, // with OO
c1 = a.negate().add(b.multiply(b)).add(b.divide(a)), // without OO
c2 = -a + b*b + b/a; // with OO
if (c1.compareTo(c2)<0 || c1.compareTo(c2)>0) // without OO
System.out.println("impossible");
if (c1<c2 || c1>c2) // with OO
System.out.println("impossible");
HashMap<String, String> map = new HashMap<>();
if (!map.containsKey("qwe")) map.put("qwe", map.get("asd")); // without OO
if (map["qwe"]==null) map["qwe"] = map["asd"]; // with OO
}
}JavaC/Netbeans: 0.5
JavaC8: 0.5
Eclipse: 0.5
IntelliJ IDEA: 0.7Note plugin versions are independent. If version for X > version for Y then it doesn't mean Y is behind feature wise.
16 Nov 2019. IntelliJ IDEA plugin v0.7 released with support of IDEA 2019.2+.
20 May 2017. IntelliJ IDEA plugin v0.6 released with support of IDEA 2017.
14 July 2016. As a workaround Eclipse plugin works fine on Eclipse 4.4+ if you install Scala IDE plugin first.
2 Feb 2016. IntelliJ IDEA plugin v0.5 released with support of IDEA 15. Requires Java8 to run the plugin.
10 April 2015. IntelliJ IDEA plugin v0.4.1 released with support of IDEA 14.1.
27 January 2015. Eclipse-oo-plugin version 0.5 released with support of reverse binary operator overload.
2 December 2014. New feature: Reverse binary operator overload via operatorRev methods.
Plugin versions updated:
JavaC7 & JavaC8: 0.5
IntelliJ IDEA: 0.4. Support of IDEA 14
31 May 2014. Javac8 plugin version 0.1.1 released. Removed runtime depencendy on nbjavac.
24 May 2014. IntelliJ IDEA plugin v0.3.1 released. Bugfixes for IDEA 13 Ultimate and for type resolution for binary expressions with primitives.
30 April 2014. IJPLA published a paper about Java-OO.
3 Feb 2014. New JavaC8 plugin version 0.1 for JDK8 was released. It has the same features as JavaC plugin for JDK7 but doesn't work in Netbeans yet.
12 Jan 2014. JavaC plugin version 0.4 and Eclipse plugin version 0.4 released. Now operator overloading perform autoboxing/autounboxing primitive to/from wrapper types where appropriate. Fixed javac plugin bug with index-set OO.
3 Jan 2014. JavaC plugin version 0.3 released. Fixed #10 javac: binary operator adds erroneous cast on 1st operand.
8 Sep 2013. Eclipse plugin version 0.3 released. Removed copypasta from Eclipse Compiler. Plugin should be more steady agains compiler changes.
14 May 2013. IntelliJ IDEA IDE plugin v0.2.1 with IDEA Ultimate Edition support.
17 Apr 2013. IntelliJ IDEA IDE plugin v0.2.
26 Nov 2012. Version 0.2 released. New feature: Assignment operator overloading via static #valueOf method.
Just add to classpath: javac8-oo-plugin.jar for JDK8 or javac-oo-plugin.jar for JDK7.
javac -cp javac8-oo-plugin.jar <sources>Demo at examples/compile.sh
Click in menu: Help - Install New Software. Enter in Work with field:
http://amelentev.github.io/eclipse.jdt-oo-site/Tested on Eclipse Standard 4.3.2. Should work with older versions too.
To work on 4.4+ you need to install Scala IDE plugin (or similar plugin with Equanox weaving). You can find it in Help -> Eclipse Marketplace. This is workaround until normal solution will be found. Tested on 4.4 and 4.6.
Project Properties -> Build -> Compiling.Tested on 7.2.1
File -> Settings -> Plugins -> Browse repositories. Mirror: idea-oo-plugin.jar) Menu File -> Settings -> Compiler -> Annotation Processing -> Enable annotation processingjavac compiler in Settings -> Java Compiler -> Use compiler. Add javac-oo-plugin.jar to File - Settings - Compiler - Annotation Processors - Processor path
add to build.gradle:
repositories {
maven { url 'http://amelentev.github.io/mvnrepo/' }
}
dependencies {
compile 'java-oo:javac-oo-plugin:0.5'
}Look at javac-oo-mvndemo/pom.xml
Read the paper to learn more. Supported operators (operator to method name map):
binary:
| OPERATOR | METHOD NAME|
-------------------------
| + | add |
| - | subtract |
| * | multiply |
| / | divide |
| % | remainder |
| & | and |
| | | or |
| ^ | xor |
| << | shiftLeft |
| >> | shiftRight |If left operand has no such method then the plugin will try to use 'reverse' method <methodName>Rev on right operand.
So 2*a will be transformed to a.multiplyRev(2) if a has such method.
unary:
| - | negate |
| ~ | not |comparison:
| <, <=, >, >= | compareTo | example: `a < b` <=> `a.compareTo(b)<0`
`==` and `!=` are not overloadable because it will break thingsindex:
| [] | get | `v = lst[i]` <=> `v = lst.get(i)`
| []= | set, put | `map[s] = v` <=> `map.put(s,v)`, `lst[i] = v` <=> `lst.set(i,v)`assignment:
| var = expr | var = VarClass.valueOf(expr) |if expr is not assignable to var and var is an instance of VarClass and expr has type ExprType and there are static method VarClass#valueOf(ExprType)
then var = expr is transformed to var = VarClass.valueOf(expr).
example:
BigInteger a = 1 is transformed to BigInteger a = BigInteger.valueOf(1)
These methods exists in many java classes (example: BigInteger, BigDecimal) so you can use operators on them "out of the box". Or you can add these methods to your classes to use OO (see examples/Vector.java).
javac-oo-plugin
cd java-oo; mvn clean install. Or import maven settings in your IDE.eclipse-oo-plugin
idea-oo-plugin
by-products:
"Java Modular Extension for Operator Overloading", IJPLA, April 2014.