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Comment by simmonmt | Hacker News Reader

I can't tell if you're being sarcastic or not. I figured transpiling would get you something that's at least black box testable using modern techniques. Then you start incrementally converting bits of it into idiomatic Java, adding more and more tests as you go. So it didn't seem like madness? But I've never done such a thing before, and am guessing there are a zillion problems with that approach. Not least that it would require an organizational commitment to stick with the conversion. Stop halfway through and sure you've got the opaque spaghetti they were worried about.

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Not being sarcastic. They have working code and a staff of engineers that understand it currently. Transpiling it migrates the code to an intermediate state that no one understands, so why do that if you have to rewrite it again anyway?

> Not being sarcastic. They have working code and a staff of engineers that understand it currently. Transpiling it migrates the code to an intermediate state that no one understands, so why do that if you have to rewrite it again anyway?

If you have engineers that understand the old code, couldn't they just continue to maintain it in that form and transpile it until it's converted to idiomatic Java?

So what does the transpiling get you in that world? You can already run the old code on modern hardware (per tfa) and you already have people who understand the existing assembly to help do a rewrite...

> So what does the transpiling get you in that world? You can already run the old code on modern hardware (per tfa) and you already have people who understand the existing assembly to help do a rewrite...

Basically what the ancestor comment enumerated. It basically allows for a more conservative and incremental approach to rewriting things, since it would give you the ability to mix old and new code.

It seems like they plan to do some parallel testing, but if they used the transplier (and it was correct), they could probably do that at a much lower level (e.g. run both functions in parallel in PROD but only use the "old" functions results, log any discrepancies, you know you're done when there haven't been any for a while).

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