Using strings in a case construct
in [Lisp]
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From: Pillsy on 5 Jan 2010 11:09 On Jan 5, 10:02 am, Kenneth Tilton <kentil...(a)gmail.com> wrote: > Pillsy wrote: [...] > >> If you get a string, quick, intern it. > >> * But it /was/ funny to see the contorted monstrosities up with which > >> they came. kt > > Like using FIND-SYMBOL instead of INTERN. Heathens! > Now, Pillsy, we talked about you needing to read the notes: > "Notes: find-symbol is operationally equivalent to intern, except that > it never creates a new symbol." > So if you /get/ a string (say, the column name of a CSV file) quick, > intern it. Do not build a string version of Lisp. All the keys in the CASE statement were interned when the original DEFUN was read. That means that if you use INTERN on the user input, when the dingbat using your cool CASE-based command loop types "svae" instead of "save", you'll be the proud owner of the brand-new |svae| symbol. Whoo- hoo? > Why do You People bother trying to correct me? USENET: where pedantry goes to die. Cheers, Pillsy
From: Kenneth Tilton on 5 Jan 2010 11:42 Pillsy wrote: > On Jan 5, 10:02 am, Kenneth Tilton <kentil...(a)gmail.com> wrote: >> Pillsy wrote: > [...] >>>> If you get a string, quick, intern it. > >>>> * But it /was/ funny to see the contorted monstrosities up with which >>>> they came. kt > >>> Like using FIND-SYMBOL instead of INTERN. Heathens! > >> Now, Pillsy, we talked about you needing to read the notes: > >> "Notes: find-symbol is operationally equivalent to intern, except that >> it never creates a new symbol." > >> So if you /get/ a string (say, the column name of a CSV file) quick, >> intern it. Do not build a string version of Lisp. > > All the keys in the CASE statement were interned when the original > DEFUN was read. Don't exacerbate our already low opinion of you. The context was a larger rule, something good teachers know about. You seem to be still talking about the fish at hand. > > That means that if you use INTERN on the user input, when the dingbat > using your cool CASE-based command loop types "svae" instead of > "save", you'll be the proud owner of the brand-new |svae| symbol. Whoo- > hoo? > >> Why do You People bother trying to correct me? > > USENET: where pedantry goes to die. s/goes to/never/. s/./s./. kt -- http://www.stuckonalgebra.com "The best Algebra tutorial program I have seen... in a class by itself." Macworld
From: dan on 5 Jan 2010 12:07 Kenneth Tilton <kentilton(a)gmail.com> writes: >> USENET: where pedantry goes to die. > > s/goes to/never/. > s/./s./. "s.SENET: where pedantry never die." "... think 'I know, I'll use a regex'. Now they have two problems" -dan
From: Pillsy on 5 Jan 2010 12:34 On Jan 5, 11:42 am, Kenneth Tilton <kentil...(a)gmail.com> wrote: > Pillsy wrote: > > On Jan 5, 10:02 am, Kenneth Tilton <kentil...(a)gmail.com> wrote: [...] > >> So if you /get/ a string (say, the column name of a CSV file) quick, > >> intern it. Do not build a string version of Lisp. > > All the keys in the CASE statement were interned when the original > > DEFUN was read. > Don't exacerbate our already low opinion of you. It was one thing to learn that you don't like me, but to learn that your tapeworm doesn't like me either? :sob: > The context was a > larger rule, something good teachers know about. You seem to be still > talking about the fish at hand. Using FIND-SYMBOL instead of INTERN doesn't mean that you're making your own screwy string-based Lisp, it just means that you only want to handle a pre-defined inputs. Maybe you do, and maybe you don't, and it really depends on what you were trying to do in the first place. Some "larger rule" you got there. Cheers, Pillsy
From: Thomas A. Russ on 5 Jan 2010 20:15
Kenneth Tilton <kentilton(a)gmail.com> writes: > * But it /was/ funny to see the contorted monstrosities up with which > they came. kt Actually, I think the point of the contorted monstrosties was to demonstrate that while you COULD make it work, you wouldn't want to. -- Thomas A. Russ, USC/Information Sciences Institute |