NOP in TCL

[Joe Fritz]

In article <peba-29079...@nachos.nixu.fi>,
Petri Aukia <pe...@nixu.fi> wrote:
>
>I have an entry field with a definition for "bind Text <Any-KeyPress>". I'd like to disable the Return and Tab keys in the field. The obvious "bind Text <Return> {}" removes any binding associated with the keypress, leaving it at the mercy of the Any-Key.
>
>Now it seems I'd need a command as small as possible with no side-effects. This would in fact be an equivelant to the NOP -command in assembly language.
>--
>Petri Aukia <pe...@nixu.fi>

How about :
proc nop {args} {}

I've used this in several places, and it works fine.
--

-joe (jfr...@rdrc.rpi.edu)

[Petri Aukia]

[Tom Tromey]

>>>>> "glv" == glv <g...@oblivion.utdallas.edu> writes:

glv> Petri Aukia writes:
>> > Now it seems I'd need a command as small as possible with no
>> side-effects. This would in fact be an equivelant to the NOP -command
>> in assembly language.

glv> This makes a nice no-op:
glv> while 0 {}

glv> You can also define one that's a little more self-documenting:
glv> proc nop {} { return "" }

glv> Both have the same effect: they do nothing and return an empty string.
glv> The first one is just a tiny bit faster.

Why not use ";"?

bind $win <whatever> {;}

Tom

--
tro...@cns.caltech.edu
"In a riddle whose answer is chess, what is the only prohibited word?"
I thought a moment and replied, "The word chess".
-- Jorge Luis Borges

[g...@oblivion.utdallas.edu]

Petri Aukia writes:
>
> Now it seems I'd need a command as small as possible with no
> side-effects. This would in fact be an equivelant to the NOP -command
> in assembly language.

This makes a nice no-op:
while 0 {}

You can also define one that's a little more self-documenting:

proc nop {} { return "" }

Both have the same effect: they do nothing and return an empty string.

The first one is just a tiny bit faster.

---glv

[Jay Sekora]

Semicolon and space are good no-ops that don't have much overhead.
Using a space is the standard way of making a window binding that
doesn't do anything, but that prevents the window class bindings from
being invoked:

bind $window <key> { }

rather than

bind $window <key> {}

--
Jay Sekora j...@it.bu.edu
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