lambda functions

Posted Dec 10, 2005 5:49 UTC (Sat) by mvogt (guest, #34379) [Link]

Well, all ideas are old, of course, but the feature that separates C++ from its closest peers (probably Ada, Eiffel, Objective-C) is the support for compile-time metaprogramming.

It's certainly not elegant, and was almost accidental in its design, but it combines very well with C++'s don't-pay-for-what-you-don't-use philosophy, and its ability to adjust its interface through operator overloading.

But, the point that these are all old ideas is valid. Their age probably indicates the amount of time and experience required to get a community of implementors and developers to assimilate a set of ideas.

Posted Dec 10, 2005 8:28 UTC (Sat) by ncm (subscriber, #165) [Link]

None of those scripting languages, nor "web languages", nor Visual Basic came from academia. For that matter, neither did FORTRAN or COBOL. Most have been reviled by academia, for generally good reasons. The various LISPs, Prologs, Haskell, the MLs, and suchlike have largely failed to escape academia, also for good reasons. Industry briefly flirted with Algol, Pascal, Ada, and their ilk, as well as Smalltalk, and then largely abandoned them, again for good reasons.

C++, in its original conception, supported one important new concept: the destructor. Languages conceived since have failed to adopt it, limiting the effectiveness of their exception handling, and the languages' industrial usefulness. (No, "finalize" doesn't help.)

Later additions, particularly templates in the form standardized by ISO, enabled STL, Boost, and a constellation of matrix- and signal-processing libraries that outperform languages specialized for the purpose. Only CAML has matched C++'s capability to define fast, powerful libraries, but often cannot be used industrially because of its limited support for resource management.

Object orientation has turned out not to be nearly so important as the '90s hype machine suggested. Languages designed to the hypesters' criteria have turned out peculiarly limited.

Why should academia care about industrial usefulness? Arguably, no reason; certainly academic art and literary criticism have precious little to do with actual art or literature. However, an academic who cares to avoid sterility and irrelevance must confront fundamentally hard, large real-world problems. Such problems are, by their nature, not limited to conveniently proscribed domains. Tools to address them must be equally well prepared for bit twiddling, lambda calculus, hard-core numerics, real-time hardware resource management, fancy data structures, and what-have-you. Academic CS department hostility to serious engineering needs leaves its graduates ill-prepared to contribute.