objc2java

Convert pure ObjectiveC code to pure Java code, libraries be damned.

usage

Pipe an ObjectiveC file into objc2java and we will convert what we can.

> cat tests/hello.m | objc2java
// First program example

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
  NSAutoreleasePool *pool = new NSAutoreleasePool();
  NSLog("Hello, World!");
  pool.drain();
  return 0;
}

For comparison, the original ObjectiveC file looked like this.

> cat tests/hello.m
// First program example

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
  NSLog (@"Hello, World!");
  [pool drain];
  return 0;
}

purpose

The goal is to help programmers port ObjectiveC code to Java by automating the boring parts. We help, but we don't do all the work: the generated code won't compile, and will still contain a lot of ObjectiveC idiosyncrasies. The idea is to let the programmer focus on translating those idiosyncrasies instead of wasting time endlessly translating [object method: arg] into object.method(arg).

status

So far, only the method call syntax is converted.

future work

Coming up next: customizable idiom translation (i.e. [[AAA alloc] init] becomes new AAA()).

After that: method signatures.

By the way, since the parser is based on invertible-syntax, it would not be a lot of work to do the translation in the opposite direction, i.e., converting the syntax from Java to ObjectiveC. But there is already a tool for that, called java2objc.