For some reason I could not reply to the original thread...
Begin forwarded message: > From: "Stephen C. Gilardi" <squee...@mac.com> > Date: February 6, 2009 12:49:34 PM EST > To: Eric Thorsen <ethor...@enclojure.org> > Subject: Re: Patch: universal main() with repl/script/compile > > Hi Eric, > >> I've been using the repl in clojure,main (which is great, BTW) but I > > Thanks! > >> have a question as to why the main loop is not a "pure" REPL? >> I am able to substitute all parts except that the *in* stream is >> mucked with in the loop with the skip-whitepace and skip-if-eol which >> means if I do not want that stuff to happen, I am out of luck. Can >> you shed some light on the problem you were trying to solve there and >> whether or not that logic can be moved into the default read function >> instead of being inside the loop? > > Regarding skip-whitespace: > > Good questions. clojure.core/read already does skip-whitespace > internally so you won't be avoiding that as long as you use it. The > downside of clojure.core/read doing that (rather than something I > control in the repl) is that clojure.core/read doesn't return at end- > of-line. One goal of making a nicer repl was to prompt for each > line: if the user types a blank line, give another prompt. That > isn't possible if I leave the current clojure.core/read in charge of > skipping whitespace. It considers the end-of-line as just more > whitespace and continues skipping. > > Another goal was not to prompt again if there's more input on the > same line. Arguably, printing only the last value on the line would > also be correct (making each line (at least logically) a "do"), but > I found the following old behavior kind of annoying/confusing/ > unsightly: > > user=> 1 2 3 > 1 > user=> 2 > user=> 3 > user=> > > Regarding skip-if-eol: > > The call to skip-if-eol is to support (read-line) (and other input > stream reads) from the repl. In many cases, command interpreters > (like unix shells) consume the eol that terminates a line so that > other code can read from the input stream "cleanly". If I don't do > skip-if-eol, the response from (read-line), for example, will always > be blank (when typed on a line by itself) because the eol will still > be on the input stream. > > I'll look at working these operations into a repl-read function so > they can be overridden/elided. It looks now like that that function > will probably need an end-of-stream argument and an end-of-line > argument passed in as sentinel values to return on those occasions. > (see clojure.main/eof). > > Thanks for the feedback. I'll look at this tonight or over the > weekend. If you have any further ideas or suggestions, I'll be happy > to hear them and to answer any questions. > > Thanks, > > --Steve > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
