Re: [OT] language tricks (was: creating menu's)
On Tue, May 08, 2007 at 09:34:35PM -0400, Douglas Allan Tutty wrote:
On Tue, May 08, 2007 at 01:22:10PM -0700, Bryan Irvine wrote:
I need a fairly simple menu, and have thought about just simple
selects but figured now would also be a good time to learn something
new as well. It's nothing so complex that I need to go ncurses to do.
Just a basic option 1 then option 3 then run some command
thing.
My front-ends I do in python. It doesn't have a case/select. I just
use if/then/elif/
Then there's Fortran with computed gotos; very slick. I forget the
syntax but is something like goto (10+choice)
11 ch1()
...
12 ch2()
...
13 ch3()
...
It means that only one computation takes place instead of one comparison
for each choice until one matches.
Just pointing out: if Python can do the job at all, you almost certainly
don't need that kind of micro-optimization in Fortran code. Also, this
is a menu. Efficiency is not exactly a big goal.
However, and this is where I go completely off-topic, while we're at it,
you don't need Fortran for this, most languages have equivalent
constructs (C):
switch(option) {
case 1:
...
case 2:
...
case 3:
...
default:
/* error! */
...
}
or even
void (*dispatch[])(void) = {
proc_opt1,
proc_opt2,
proc_opt3
}
void
proc_opt1(void)
{
...
}
void
proc_opt2(void)
{
...
}
void
proc_opt3(void)
{
...
}
In languages with higher order-functions, this can be written even more
concisely (Scheme):
(define dispatch
(vector
(lambda () ...)
(lambda () ...)
(lambda () ...)))
A suiteable make-menu macro could even make something like
(define toplevel-menu
(make-menu
(opt1 (lambda () ...))
(opt2 (lambda () ...))
(another menu another-menu)))
(define another-menu
(make-menu
(opt3 (lambda () ...))
(opt4 (lambda () ...))
(top toplevel-menu)))
do what it looks like it should do.
However, all of this is massively overkill. Just use a shell script.
Joachim
--
TFMotD: mirroring-ports (7) - how to build a mirror for ports distfiles
Re: [OT] language tricks (was: creating menu's)
On Wed, May 09, 2007 at 10:56:57AM +0200, Joachim Schipper wrote: On Tue, May 08, 2007 at 09:34:35PM -0400, Douglas Allan Tutty wrote: On Tue, May 08, 2007 at 01:22:10PM -0700, Bryan Irvine wrote: I need a fairly simple menu, and have thought about just simple selects but figured now would also be a good time to learn something new as well. It's nothing so complex that I need to go ncurses to do. Just a basic option 1 then option 3 then run some command thing. My front-ends I do in python. It doesn't have a case/select. I just use if/then/elif/ Then there's Fortran with computed gotos; very slick. I forget the syntax but is something like goto (10+choice) for each choice until one matches. Just pointing out: if Python can do the job at all, you almost certainly don't need that kind of micro-optimization in Fortran code. Also, this is a menu. Efficiency is not exactly a big goal. I don't do enough programming to want to keep track of multiple languages. If I have to read a program in 10 years I want to know what its trying to do. C has too much punctuation everywhere. So I only program in Python and Fortran. However, and this is where I go completely off-topic, while we're at it, you don't need Fortran for this, most languages have equivalent constructs (C): In languages with higher order-functions, this can be written even more concisely (Scheme): However, all of this is massively overkill. Just use a shell script. Shell is too much like C (punctuation and spacing matter). (sorry if this sounds anti-unix). I use shell if its like a dos bat file, sequential. Once I have to test conditions and branch I switch to python. Then if something takes a long time (or I know it will before hand), I use fortran 77. Unfortunaly, I can't get my head around regex either. Two hours after I'v written it I can't understand it. So I code it in python or fortran. Doug.
