Oh, I remember. Agreed, it is most probably a bad choice then. One part of my brain likes:
"By wrapping a block in/with[*] a decimal.Context, <elaborate on consequences>" "xml.Tags used to wrap a block will print '<tag>' before the block is entered, and '</tag>' after execution has left." What do you think? [*] I'm not sure what's the correct English version, sorry.. if it is "with", it migh be a nice way to place a hyperlink to the language reference. On 7/3/05, Raymond Hettinger <[EMAIL PROTECTED]> wrote: > I'm referring to the specific meaning of "guard" in a computer science > context: > > http://www.computer-dictionary-online.org/guard.htm?q=guard > > From David Gries, The Science of Programming, if statement contains two > entities of the form B --> S wehere B is a Boolean expression and S a > command. B --> S is called a guarded command. > > I believe that terminology is rooted in Dijkstra's language of guarded > commands (used to express and facilitate program proofs). They are > essentially the same as conditionally executed statements but may be > executed non-deterministically: > > http://cs-exhibitions.uni-klu.ac.at/contentGuardedCommand.php > > Also, I believe the pattern matching part of Prolog clauses are called > guards; however, the conditional execution is deterministic (the first > match is the one that fires) and potentially recursive. > > This terminology is used consistently among various functional > programming languages. From, > http://www.cs.ecu.edu/~karl/astarte/glossary.html , "A guard in a case > is the condition that is being tested. For example, in case a => b, > expression a is the guard." > > In predicate calculus, the phrase, "strengthening the guard" has a > specific meaning with the "guard" part being consistent with the above. > One example: > > http://www.cs.utexas.edu/users/psp/unity/notes/07-89.pdf > > IOW, guard is a specific term, not an amorphous metaphor that can be > accurately applied to the enter/exit or enter/leave pair. > > > Raymond > > > > > > > -----Original Message----- > > From: Michael Walter [mailto:[EMAIL PROTECTED] > > Sent: Sunday, July 03, 2005 10:28 PM > > To: Raymond Hettinger > > Cc: [EMAIL PROTECTED]; python-dev@python.org > > Subject: Re: [Python-Dev] Terminology for PEP 343 > > > > Hmm, I think I'm seeing mostly the (guarded) entry/exit part of > > "guard" metaphor, but I see what you mean (not allowing "entry", so to > > say, right?). Not sure. > > > > Michael > > > > On 7/3/05, Raymond Hettinger <[EMAIL PROTECTED]> wrote: > > > > "Guarding a scope with a decimal.Context() object <explain > effect>." > > > > > > Doesn't "guard" suggestion conditional execution? > > > > > > > > > Raymond > > > > _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
