From help-octave-request at bevo dot che dot wisc dot edu Fri Jan 28 17:11:05 2000 Subject: Re: Suggestion: add do-enddo(condition) From: "Johan Kullstam" To: help-octave at bevo dot che dot wisc dot edu Date: 28 Jan 2000 18:11:25 -0500 Francesco Potorti` writes: > Sorry, my previous message was somehow garbled. > > John Eaton wrote: > 1. do ... enddo (condition) > 2. do ... while (condition) > 3. do ... until (condition) > 4. repeat ... until (condition) > 5. repeat ... while (condition) > > I don't like `while', because of possible (certain) confusion while > reading sources, as you have observed, so 2 and 5 are ruled out. > However, I like a positive test (while) much more than a negative one > (until), because in the case of `until' we would have two kinds of > loops: ok i can agree with the above. how about do whilst (cond)? whilst is not while and the emacs mode could easily grok it. > while () ... endwhile > do/repeat ... until () > > which are different in two orthogonal ways: > - test made at beginning/end > - positive/negative test > > I think it is better to have only a single difference. I see this as a > simplicity issue in the definition of the language. i am all for simplicity. > Moreover, the `do/repeat ... until()' construct is different from all > other loops, which can be ended with and end* keyword. > > I propose the following, that should address these two issues: > > do ... enddo while (condition) > > or alternatively > > repeat ... endrepeat while (condition) argh. imho this is worse than the disease. no construct has garbage after the end

either so it's not like it's conforming to anything. this form is going to be weird by its very nature. > Obviously this means that we need two keywords to end the loop: `enddo > while' or `endrepeat while', and this is not nice, but at least it > does address the two above issues. no it doesn't. people and emacs will still be confused by the context sensitive "while" keyword. it doesn't solve the problem (two kinds of while) while at same time adding gratuitous verbiage. -- J o h a n K u l l s t a m [kullstam at ne dot mediaone dot net] Don't Fear the Penguin! ----------------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.che.wisc.edu/octave/octave.html How to fund new projects: http://www.che.wisc.edu/octave/funding.html Subscription information: http://www.che.wisc.edu/octave/archive.html -----------------------------------------------------------------------