subprograms

Networks are fundamentally unreliable, and that means that idempotency of subprograms is a very important property.

Server for verifone pos, RPC servers to allow any client to execute natural (it's a programming language) subprograms.

Ada2012 for example, introduced design by contract with support for formal verification in conforming subprograms.

This even happens in formally verified code where there's literally proven preconditions on subprograms that show a given state can never be achieved.

First of all, Ada may have already made a copy of the value; small (register-sized) values tend to be passed by copy into subprograms.

That is, the system should first be made to run, even though it does nothing useful except call the proper set of dummy subprograms.

I'd be curious to see a serious breakdown of which schools are seeing increased enrollment, and in which subprograms of CS.

Like good god, how much time do we waste on rewriting the same little subprograms?

Then, bit by bit it is fleshed out, with the subprograms in turn being developed into actions or calls to empty stubs in the level below.

Quite a few projects use Erlang extensively (Heroku, GitHub, and (if I remember right) Chef use a lot of Erlang, usually to route requests to subprograms written in other languages like Ruby).

This is kind of the case for IO in Haskell[0], but for subprograms/procedures/functions I tend to find it an absolutely essential property, both in terms of reasoning and in terms of testability.

They are using the imperative model at the scale of a single machine, where its appropriate, but the functional model at the scale of the cluster, so subprograms can be retried and executed in any order.

"Well defined subprograms" is key here -- in a mutable language like Go, goroutines are not well-defined subprograms, so exceptions are tricky to use correctly.

In most early programming languages "functions" were functions in the mathematical sense, while other kinds of subprograms were named procedures or subroutines.

The subprograms aren't "libraries" in a sense that I do much faster changes to the "interface" but just having them makes everything much more maintainable.

Interesting to read that djb is in favor of automatic exception handling rather than explicitly checking return codes: "Fortunately, programming languages can—and in some cases do—offer more powerful exception-handling facilities, aborting clearly defined subprograms and in some cases automatically handling error reports.