Re^2: detecting an undefined variable

In reply to Grandfather, yes, I pick-and-mix code from other places, but it is not a concern that such variables may cause the code to behave badly. But exactly the opposite. I WANT those variables, and having exactly their original purpose and value.

May I digress? I had been writing Fortran and C since they were respectively invented. I could not deal with C++. I started with Perl shortly after Llama came out (94, 95 ish). Friends tell me I should switch to Python. But I do not for exactly the above (C++) reason. I love it that Perl pretty much successfully hides the Object code. I will be 80 in a few weeks and I am not likely to relearn much else from here on out.

Thanks so much for all of your advice and concerns.

Comment on Re^2: detecting an undefined variable

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Re^3: detecting an undefined variable by GrandFather (Saint) on Sep 23, 2019 at 05:13 UTC
" I WANT those variables, and having exactly their original purpose and value." In that case your concern should still be that the variables and patched in code behave badly. If you understand the original code well enough to transplant it then you should understand it well enough to put a nice wrapper around it so it doesn't interact badly with the rest of your code. The wrapper ensures you don't have undeclared variables so your original concern is moot. The trick of course is understanding the borrowed code well enough that it can thrive when transplanted. Just the process of wrapping the transplanted code in a sub and providing a well defined set of parameters and results will drive understanding of what the borrowed code needs and what it does. Strictures of course help that process by pointing out issues early. If you are seriously concerned that the code behave as expected the next level is to write a test suite against the code. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]

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Re^3: detecting an undefined variable
by GrandFather (Saint) on Sep 23, 2019 at 05:13 UTC

" I WANT those variables, and having exactly their original purpose and value."

In that case your concern should still be that the variables and patched in code behave badly. If you understand the original code well enough to transplant it then you should understand it well enough to put a nice wrapper around it so it doesn't interact badly with the rest of your code. The wrapper ensures you don't have undeclared variables so your original concern is moot. The trick of course is understanding the borrowed code well enough that it can thrive when transplanted.

Just the process of wrapping the transplanted code in a sub and providing a well defined set of parameters and results will drive understanding of what the borrowed code needs and what it does. Strictures of course help that process by pointing out issues early. If you are seriously concerned that the code behave as expected the next level is to write a test suite against the code.

Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

[reply]