So you want to port code from one language to another, huh?

[minxomat]

In my last job and for a number of private projects I needed to port huge amounts of code between languages. I'm specifically talking about ports on one and the same platform. Here are some tips I consider useful (from experience) in no particular order:

a) Pre-porting

Obviously, create a safe (sandbox) copy of whatever you are about to port. Separate it completely from anything important, even if this means setting up another production environment.

b ) While porting

• Never try to fix something on the fly
• If you need to substitute some paradigm (e.g. nested structures) not available in the target language, write a substitute and test it before starting to translate
• Back up target code on almost every new LOC, use git and write an auto-commit script when in doubt
• Go on a module by module basis, never translate whole code pages the same time
• Never change any variable / constant etc. names on the fly
• If time and budget allows, always write test wrappers for longer modules to verify every code path in source and target code (unless dependent on user input, of course)
• Always assume the code you are porting was written by a person desperately trying to confuse you, even if it was you who wrote it!
• Some languages have a (or multiple) different array base(s)
• Don't trust automated translation (I know C#<->VB.NET is tempting) tools, never attempt to create any automated translation tools
• Recreate not only code, but also file-structure, even if this is bad practice in the target language
• Keep the case-sensitivity of the target and source language in mind
• Don't delete anything on the way, just comment out
• You don't want to care about any best practices or conventions, you care about a 1:1 copy; everything else is post-porting

c) Post-porting

Create a whole backup of the new code and put it somewhere safe. Then, and only then, start working with a fresh copy of the new code.

After all the projects I've been through, I can only say the above also applies when the source (no pun intended) code is only 200 LOC long. If the source language is complex enough, you'd be surprised how bad one can f*ck things up. If you have any additional tips or stories regarding ports, leave them here.  

 

[Xandy]

It was a good read.  Seemed like pretty good practices for any code projects.

[mLipok]

  On 7/21/2015 at 7:24 AM, Xandy said:

It was a good read.  Seemed like pretty good practices for any code projects.

I agree.

Can you or me make new Wiki Page of course copy Paste ?

EDIT: the question was adressed to @minxomat

Edited July 21, 2015 by mLipok

[minxomat]

  On 7/21/2015 at 8:02 AM, mLipok said:

Can you or me make new Wiki Page of course copy Paste ?

If you feel like it, go for it.

[mLipok]

Thanks.
If no other members have any objective I will handle this in few days.

Cheers,

mLipok

[jvanegmond]

If you're not proficient in both languages, you're going to have a bad time.

Even simple things like data types can be different in closely related languages. Maximum value of a char in C++ is 0xFF, but in C# it is 0xFFFF.  The correct way to translate is to use a byte in C#, which has a maximum value of 0xFF. These are closely related languages. Good luck handling overflows and "bitfucking" in other languages.

[jaberwacky]

  On 7/21/2015 at 4:44 AM, minxomat said:

Don't delete anything on the way, just comment out

Better yet, use some sort of a code repository.