[u-u] wow, post-tested loops in sh

arocker at Vex.Net arocker at Vex.Net
Mon Jul 4 14:26:10 EDT 2016

> | On Mon, 04 Jul 2016 10:25:24 EDT, "D. Hugh Redelmeier" writes:

> Yes.  Or more accurately: Duff's Device is possible because of a
> counter-intuitive design choice in C's case. It even surprised the
> designers.

In general, Hugh's right about designing-out errors, but any non-trivial
system, especially a programming language, is likely to be abusable in
some creative manner not anticipated by its designers. (Even if it
requires entirely misunderstanding or subverting the intended paradigm.)

If a language is Turing-complete, it can compute anything computable, so
expecting the authors to foresee every possibility sounds like the Halting

For a practical case-study of designing-out errors, look at the story of
the B-17's landing gear and flap switches.

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