🚀 go-pugleaf

In article <1172@meaddata.mead.UUCP> mead!gor...@uccba.uc.edu writes:
>In light of the stupid user discussion, how about a discussion of stupid and
>embarrassing programming errors.
[Story of a recursive function overflowing the stack on a long input.]

There are programming mistakes that can result, not from stupidity,
but simply from moving to a different type of programming language.  A
few years ago a friend at school showed me a program that had worked
fine when she'd tested it, but came back from grading with the
supremely unhelpful message, "This dumps core."  The assignment was a
short filter written in C.

The problem was that her previous programming course had used Scheme,
emphasizing general programming techniques.  Scheme guarantees that it
will compile a tail-recursive function into a loop.  Her filter code,
while beautifully written, was handling the main loop of the filter
tail-recursively, and the program overgrew the stack as soon as the TA
gave it too many characters of input.

She looked rather shocked when I told her that most C implementations
wouldn't handle that case nicely, but she recoded it into a while-loop.
--
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David Wald                                           wa...@theory.lcs.mit.edu
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