JavaScript and Scheme - Re: teaching programming to kids

On 05/01/12 12:09 PM, Liam Proven wrote: Another approachable, practical discussion of closures, with applications, is in Douglas Crockford's "JavaScript - The Good Parts". In fact it's hard to do anything half interesting in JavaScript *without* using closures. Many people including Crockford say this is the #1 thing JavaScript got right (and if Eich had had more time and leeway, he'd have incorporated more of Scheme's power). From Coders at Work* (Siebel): Peter Seibel: ------------- Let's go back to those ten days when you implemented the original JavaScript. I know that at some point someone had turned you on to Abelson and Sussman and your original idea was to put Scheme in the browser. Brendan Eich: ------------- The immediate concern at Netscape was that it must look like Java. People have done Algol-like syntaxes for Lisp but I didn't have time to take a Scheme core so I ended up doing it all directly and that meant I could make the same mistakes that others made. I didn't have total dynamic scope, like Stallman insisted was somehow important for Emacs and infested Elisp with. JavaScript has mostly lexical scope [like Scheme and Common Lisp] with some oddness to it---there are a few loopholes that are pretty much dynamic: the global object, the with statement, eval. But it's not like dollar variables in Perl before my or upvar, uplevel in Tcl. The '90s was full of that---it was trendy. But I didn't stick to Scheme and it was because of the rushing. ... Seibel: ------- So basically now people make a top-level function to get a namespace. Eich: ----- Yeah. You see people have a function and they call it right away. It gives them a safe environment to bind in, private variables. Doug's a big champion of this. It was not totally unknown to the Schemers and Lispers but a log of JavaScript people had to learn it and Doug and others have done a valuable service by teaching them. It's not like you're getting everybody to be high-quality Scheme programmers, unfortunately, but to some extent they've succeeded, so people now do understand more functional idioms at some patterny level, not necessarily at a deep level. ... Seibel: ------- In some of the discussions about ES4, you cited Guy Steele's paper, "Growing a Language". Speaking as a Lisper, to me the take-away from that was, step one, put a macro system in your language. Then all of this special sugar goes away. Eich: ----- There are two big problems, obviously. C syntax means you have a much harder time than with S-expressions, so you have to define your ASTs and were going to have to standardise them and that's going to be a pain. ... * http://www.codersatwork.com/brendan-eich.html