17db96d56Sopenharmony_ciPath: cwi.nl!sun4nl!mcsun!uunet!cs.utexas.edu!convex!usenet
27db96d56Sopenharmony_ciFrom: tchrist@convex.COM (Tom Christiansen)
37db96d56Sopenharmony_ciNewsgroups: comp.lang.perl
47db96d56Sopenharmony_ciSubject: Re: The problems of Perl (Re: Question (silly?))
57db96d56Sopenharmony_ciMessage-ID: <1992Jan17.053115.4220@convex.com>
67db96d56Sopenharmony_ciDate: 17 Jan 92 05:31:15 GMT
77db96d56Sopenharmony_ciReferences: <17458@ector.cs.purdue.edu> <1992Jan16.165347.25583@cherokee.uswest.com> <=#Hues+4@cs.psu.edu>
87db96d56Sopenharmony_ciSender: usenet@convex.com (news access account)
97db96d56Sopenharmony_ciReply-To: tchrist@convex.COM (Tom Christiansen)
107db96d56Sopenharmony_ciOrganization: CONVEX Realtime Development, Colorado Springs, CO
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137db96d56Sopenharmony_ci
147db96d56Sopenharmony_ciFrom the keyboard of flee@cs.psu.edu (Felix Lee):
157db96d56Sopenharmony_ci:And Perl is definitely awkward with data types.  I haven't yet found a
167db96d56Sopenharmony_ci:pleasant way of shoving non-trivial data types into Perl's grammar.
177db96d56Sopenharmony_ci
187db96d56Sopenharmony_ciYes, it's pretty awful at that, alright.  Sometimes I write perl programs
197db96d56Sopenharmony_cithat need them, and sometimes it just takes a little creativity.  But
207db96d56Sopenharmony_cisometimes it's not worth it.  I actually wrote a C program the other day
217db96d56Sopenharmony_ci(gasp) because I didn't want to deal with a game matrix with six links per node.
227db96d56Sopenharmony_ci
237db96d56Sopenharmony_ci:Here's a very simple problem that's tricky to express in Perl: process
247db96d56Sopenharmony_ci:the output of "du" to produce output that's indented to reflect the
257db96d56Sopenharmony_ci:tree structure, and with each subtree sorted by size.  Something like:
267db96d56Sopenharmony_ci:    434 /etc
277db96d56Sopenharmony_ci:      |     344 .
287db96d56Sopenharmony_ci:      |      50 install
297db96d56Sopenharmony_ci:      |      35 uucp
307db96d56Sopenharmony_ci:      |       3 nserve
317db96d56Sopenharmony_ci:      |       |       2 .
327db96d56Sopenharmony_ci:      |       |       1 auth.info
337db96d56Sopenharmony_ci:      |       1 sm
347db96d56Sopenharmony_ci:      |       1 sm.bak
357db96d56Sopenharmony_ci
367db96d56Sopenharmony_ciAt first I thought I could just keep one local list around
377db96d56Sopenharmony_ciat once, but this seems inherently recursive.  Which means
387db96d56Sopenharmony_ciI need an real recursive data structure.  Maybe you could
397db96d56Sopenharmony_cido it with one of the %assoc arrays Larry uses in the begat
407db96d56Sopenharmony_ciprograms, but I broke down and got dirty.  I think the hardest
417db96d56Sopenharmony_cipart was matching Felix's desired output exactly.  It's not
427db96d56Sopenharmony_ciblazingly fast: I should probably inline the &childof routine,
437db96d56Sopenharmony_cibut it *was* faster to write than I could have written the
447db96d56Sopenharmony_ciequivalent C program.
457db96d56Sopenharmony_ci
467db96d56Sopenharmony_ci
477db96d56Sopenharmony_ci--tom
487db96d56Sopenharmony_ci
497db96d56Sopenharmony_ci--
507db96d56Sopenharmony_ci"GUIs normally make it simple to accomplish simple actions and impossible
517db96d56Sopenharmony_cito accomplish complex actions."   --Doug Gwyn  (22/Jun/91 in comp.unix.wizards)
527db96d56Sopenharmony_ci
537db96d56Sopenharmony_ci     Tom Christiansen           tchrist@convex.com      convex!tchrist
547db96d56Sopenharmony_ci
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