COMEFROM

What are some more obscure control flow structures? It's easy to think that eg conditionals, loops, goto, function calls are the only ones that exist. But there is also stuff like jump tables and co-routines for instance.

Re: COMEFROM

#5

Post by ryandvm » Thu, Nov 17, 2011, 3:47 PM UTC

skynirka wrote: post #2

Have any examples of languages that implement this?

Some elements of Aspect Oriented Programming are comparable to the COMEFROM statement.

http://en.wikipedia.org/wiki/Aspect-oriented_programming#See...

Re: COMEFROM

#6

Post by brlewis » Thu, Nov 17, 2011, 3:54 PM UTC

itmag wrote: post #4

What are some more obscure control flow structures? It's easy to think that eg conditionals, loops, goto, function calls are the only ones that exist. But there is also stuff like jump tables and co-routines for instance.

I don't know if it gets any more obscure than Scheme's call/cc, which is a building block for other control flow structures. You can use it for cool things like the Racket web server, where event-driven programming can be made to feel like sequential, procedural-style programming. You can also use it for sick mind twisters like ((call/cc call/cc) (call/cc call/cc))

Re: COMEFROM

#7

Post by skimbrel » Thu, Nov 17, 2011, 3:55 PM UTC

COME FROM is the reason INTERCAL is among my favorite esoteric programming languages. That and the fact that its name is for "Compiler Language With No Pronounceable Acronym".

From Wikipedia: An actual example in INTERCAL would be too difficult to read

Gotta love it.

Re: COMEFROM

#8

Post by skimbrel » Thu, Nov 17, 2011, 3:57 PM UTC

brlewis wrote: post #6

itmag wrote: post #4

What are some more obscure control flow structures? It's easy to think that eg conditionals, loops, goto, function calls are the only ones that exist. But there is also stuff like jump tables and co-routines for instance.

I don't know if it gets any more obscure than Scheme's call/cc, which is a building block for other control flow structures. You can use it for cool things like the Racket web server, where event-driven programming can be made to feel like sequential, procedural-style programming. You can also use it for sick mind twisters like ((call/cc call/cc) (call/cc call/cc))

I remember being shown call/cc briefly in CS 61A at Berkeley and then forgetting about it until recently when I saw an article on it while I was in the middle of writing an event-driven web application using Perl and Plack. I immediately saw how useful it would be and wished I had it available to use there.

Re: COMEFROM

#9

Post by itmag » Thu, Nov 17, 2011, 3:59 PM UTC

brlewis wrote: post #6

itmag wrote: post #4

What are some more obscure control flow structures? It's easy to think that eg conditionals, loops, goto, function calls are the only ones that exist. But there is also stuff like jump tables and co-routines for instance.

I don't know if it gets any more obscure than Scheme's call/cc, which is a building block for other control flow structures. You can use it for cool things like the Racket web server, where event-driven programming can be made to feel like sequential, procedural-style programming. You can also use it for sick mind twisters like ((call/cc call/cc) (call/cc call/cc))

Please explain :)

Re: COMEFROM

#10

Post by brlewis » Thu, Nov 17, 2011, 4:09 PM UTC

itmag wrote: post #9

brlewis wrote: post #6

Earlier quoted context omitted.

I don't know if it gets any more obscure than Scheme's call/cc, which is a building block for other control flow structures. You can use it for cool things like the Racket web server, where event-driven programming can be made to feel like sequential, procedural-style programming. You can also use it for sick mind twisters like ((call/cc call/cc) (call/cc call/cc))

Please explain :)

Good explanation here: http://lambda-the-ultimate.org/node/86#comment-3806

But you have to read it slowly.