[forwarding to racket-users]
---------- Forwarded message ---------- From: Chad Albers <[email protected]> Date: Wed, May 9, 2012 at 2:22 PM Subject: Re: [racket] Rationale behind missing string-trim To: Danny Yoo <[email protected]> Happy to help you guys identify a bug. On a side note, that's not really relevant to this thread, I was wondering about your statement about #lang racket. I had assume that you just add #lang racket, if you're writing a racket script, sort of like the hash bang syntax of a shell script. Is that a correct assumption? Related, the code I'm writing is actually in a module I'm creating, and I've used this to source the racket language: (module rig racket (require racket/base (for-syntax racket/base racket/syntax)) Should I have used #lang racket? is racket/base redundant, since I have it in the module definition? Thanks for your help, if you can answer these questions for me. Chad -- Chad Albers On Wed, May 9, 2012 at 1:45 PM, Danny Yoo <[email protected]> wrote: > > On Wed, May 9, 2012 at 1:23 PM, Chad Albers <[email protected]> wrote: > > If my require reads as follows > > > > (require racket/base > > srfi/13 > > (for-syntax racket/base > > racket/syntax)) > > > > I get the following error message: > > > > module: identifier already imported from: racket at: string-upcase in: > > srfi/13 > > > > > Huh! That looks like the error reporting is misattributing the source > of the conflict. I'll send a bug report. > > The error is highlighting the "racket" in the #lang line and srfi/13, > but the true source of the conflict's really between the exports of > racket/base and srfi/13. For demonstration, try: > > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > #lang racket > (require (only-in racket/base string-upcase) > srfi/13) > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > > vs: > > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > #lang racket > (require (only-in racket/base) > srfi/13) > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; > > In the first, we tell Racket o use both the string-upcase function in > racket/base, as well as all the exports of srfi/13. Since both > requires provide a string-upcase function, there's a conflict, which > the DrRacket environment reports. > > In the second, we mask out all the exports from racket/base. So the > exports of srfi/13 can otherwise shadow everything else without > complaint. > > > > Side note: the big language of "#lang racket" provides everything in > racket/base, so the (require racket/base) is actually redundant. You > can write: > > #lang racket > (require srfi/13) ____________________ Racket Users list: http://lists.racket-lang.org/users
