On Mar 4, 2015, at 1:18 PM, Rufus <rlagg...@mail.com> wrote: > To All > > Using BSL-Lists: > > Matt't basic test works. > > (define rufus 0) > > Run, then type and execute "rufus" in the I-pane which displays 0 > > > > If I then add Alexander's example define so the def file appears as follows: > --------- > (define rufus 0) > > (define atom? (lambda (arg1) > (and (not (pair? arg1)) > (not (null? arg1))))) > ------------- > > and hit Run I get an error in the I-pane: > > "pair?; this function is not defined".
It is called cons? not pair? because BSL and friends restrict it to list construction, like TLL. > > OK, so the BSL-Lists doesn't have that function. Then when I again type > "rufus"/Enter in the I-pane I get an error "rufus; this variable is not > defined" When you have an error in a program, you get no interactions. You'd never know what these interactions really mean in the presence of an error in your definitions. 0 == 1 > So it appears the Run procedure deletes the existing environment before > running the defs file and if it finds any error in the defs file it does > not run _anything_ from that file. So "Run" will leave an empty > environment (right word?) if there is any error in the defs file. Yes. > On that note. It seems like the problems I've had relate directly to my > leaving noobie errors in the defs file. My confusion about how the defs > file code is Run - thinking that after a Run that throws and error > either the old environment (from the last successful Run) would remain > intact AND/OR that those lines which evaluate correctly in the new file > would be run despite some errors on other lines in that particular file > - slowed my understanding. > > I believe that I do have a defs file w/errors which, on Run, does not > cause an error to display in the I-panealthough it does delete the > environment. I will try to recreate it this afternoon or evening. > > As a last thought it still appears that the "#lang racket" yields better > effect than the BSL-Lists when trying follow through the TLS because > some functions shown in the TLS notes aimed at making examples and > exercises work in Scheme (eg. pair?) are not defined in the BSL-Lists. > Matt, I'm pretty sure you have reasons for recommending the BSL-Lists so > maybe I'm missing something else? > > Thank you all. > > Rufus > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
