note BrowserUk <blockquote><i></i></blockquote> <p>I've been reading a lot about constructing interpreters and VMs lately, and one thing that seems common to most new ones is the seemingly obligatory inclusion of closures; and the almost equally obligatory tales of woe, sleepless nights and extreme programming hardship that are required in order to implement them in an efficient and elegant manner. <p>Then the thought that formed in my mind was that whilst I am [http://perlmonks.com/index.pl?abspart=1;displaytype=displaycode;node_id=405888;part=1|quite happy to make extensive use of them], I was also quite happily solving my programming problems in languages that don't support them for 15+ years before I became acquainted with them. <p>So then the questions that came to me were: a) how much use do people make of them in Perl? b) How many of those uses are actually 'killer applications' of closures, rather than trivial or convenient uses of up-values in anonymous subroutines that could just as easily be done using some other mechanism that doesn't impose such demands upon the VM? <P>One of the 'killer applications' of closures often cited in FP circles, is their links to continuation passing. But continuation passing is just one method of solving a problem that can be solved in various other ways. And most of those other ways seem to impose far less runtime burdens than CP whilst achieving the same goals. <p>Hence my very open question to try and get a feel for what people do with closures in real-world code. <div class="pmsig"><div class="pmsig-171588"> <hr /> <font size=1 > <div>With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'</div> <div>Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.</div> <div>"Science is about questioning the status quo. Questioning authority". </div> <div>In the absence of evidence, opinion is indistinguishable from prejudice. </div> </font> </div></div> 1018281 1018579