OK, so the proposed solution failed once I tried to pass in the module name as a variable. Even though enter! claims to take a module-path as an argument, this will not work:
(define name "module.rkt") (module-path? name) ; reports #t (enter! name) ; error: collection "name" not found enter! is treating "name" as a module path instead of resolving it as a defined term. What I can't tell is whether this is mandatory behavior for enter!, or if it's a bug in the enter! macro. (I did look at enter.rkt, but this week, it's over my head.) Matthew Butterick On Sat, Apr 27, 2013 at 6:16 PM, Matthew Butterick <mb.list.a...@gmail.com>wrote: > Aha, combining enter! with dynamic-require seems to do the trick: > > (define (route req) > (enter! "module.rkt") > (define foo (dynamic-require "module.rkt" 'foo)) > (response/xexpr `(p ,(format "~a" foo)))) > > Once this route is running in the web server, I can make changes to > module.rkt, then click reload in the browser, and the changes will appear > in the browser. > > If this is a terrible idea let me know, otherwise I'll consider this > solved. > > > On Sat, Apr 27, 2013 at 9:56 AM, Matthew Butterick <mb.list.a...@gmail.com > > wrote: > >> I'm building a website using Scribble as the source format. As a >> development tool, I've built a web server in Python that lets me view all >> my Scribble source files and look at them in different states of >> processing. To view the results of the Scribble files, the Python server >> just sends the files to Racket via a system command (os.Popen) and reads >> the result. This works but it's slow, because it has to launch a new >> Racket thread for every request. >> >> I thought I could speed things up by rewriting the development web server >> in Racket. But having tried a few approaches, I'm not sure how to duplicate >> this functionality within a Racket web servlet: >> >> *(require <modulename>) * >> This only gets evaluated once, when the server is started. That doesn't >> help, since the <filename> is going to be passed in as a parameter while >> the server is running. >> >> *(dynamic-require <** modulename **>) * >> This gets evaluated only when invoked, and thus can take <modulename> as >> a parameter, but then <filename> can't be reloaded (this is essential, as >> the point of the system is to be able to edit the files and see the changes >> in the web browser immediately) >> >> *(enter! <modulename>)* >> This reloads the file, but it's not clear how to get access to names >> provided by <modulename>. (The documentation for enter! suggests that this >> is not how it's meant to be used anyhow.) >> >> Obviously, I could call a new instance of Racket as a system command, but >> that wouldn't offer any advantage over the current approach. >> >> >> I suppose what I'm looking for is an equivalent of the Python >> reload(<modulename>) command. >> >> >> Matthew Butterick >> > >
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