World: r3wp

Consider if we had a COUNTER! datatype. The counter would create 
a series of integers, each holding a separate base. The trick to 
COUNTER! is that it is a structure that holds more information than 
just the numbers, but also states, in the same way that a block holds 
an index or whether a port! is open or closed.

First the bad things:


- It can be complex and there are many things to consider. Many functions 
would be affected.

Now the good:


- This takes all the thinking out of building trivial counters and 
could greatly simplify it.
- It could be used as an any-base converter.
- No new functions to add specifically for it.

It should be possible to:

- Specify as many numbers per counter as we like.

- Each number would be within the limits of positive integers and 
each number would act as an integer! type.

- Extract information about which digit is currently counting or 
which number was last changed.
- Extract base information.
- Perform basic math (add/subtract).
- Perform base conversion for the entire counter.
- Perform base conversion between a counter and an integer.

A counter would hold four pieces of information:

- The base for each number
- The numbers themselves
- The last changed number as a one-based integer index

- The last numbers that were reset at last count as a block of one-based 
integer indexes

The nature of a counter:

- It would be a number!.
- It would not be a series!.

Specifying a counter:

- The above four pieces would be specified in order
- Each piece is separated by an exclamation mark
- Possible to skip pieces by leaving the field empty

- Syntax: !<base definition>!<number>!<last changed number>!<last 
reset numbers>
- Counter base alone: !12.14.16
- Counter base with number: !12.14.16!0.0.0

- Counter base with number and last changed number: !12.14.16!0.0.0!3

- Counter base with number and last changed number and last reset 
indexes: !12.14.16!0.0.0!3![2 1]
- Number without base: !!0.0.0

There's more, but it's a little much to write. :-)

Henrik, what are the different usecases, you don't talk about it 
as much.

Can you fulfill a mezzanine which simulates his expected behavior 
?
Because, just by reading your specs, i can trully figure it.

(*i can't trully...)

Ammon, what about your tests on rich-text. Is that fast enough ?

Steeve, I'm writing it up now. It's probably possible to do with 
a series of mezzanines, but it would not be very elegant.

By elegant, you mean fast enough for your need :-)

No, I mean being able to use ordinary math functions directly on 
the counter.

I'm changing my mind on not needing math and it not being a series. 
Sorry, if that seemed confusing.

Don't worry, it seems confusing only because i'm stupid :)

I just have a very clear example in MAKE-TICKS, where it would reduce 
about 10 hard to understand lines of code to 1 or 2 very clear lines 
of code.

Just to replace 10 lines of code in one usecase ? You're assuming 
Rebol should behave as your own or what ? :-)

I have encountered this problem before, where I just had to give 
up, because the problem became too complex to solve in a hurry. With 
the counter! datatype, it would not be a problem.

If it can be used to maintain large index on any data structure efficiently, 
it could be usefull. I'm waiting for your code

It'll be a while. Some things to think through first.

there is actually a built-in similarity to counter:

to-time 78
== 0:01:18

Just imagine any base instead of just !24.60.60

I don't understand the meaning of the tuple. Is that just an indentifier 
?

it's not a tuple. each number is a separate full integer.

This proposed datatype looks quite complex. Are you sure it's wise 
to add it to Rebol? Doesn't this just feed into lobbying for the 
user datatype? I might first implement your counter as mezzanine, 
solve the problem you have at hand, then maybe try to imagine how 
it could be specified using a user datatype...

yes, Anton, I agree it's complex, but I'm not sure it's any more 
complex than object! or port!. A mezzanine would only partially solve 
the problem, but it would allow similar behavior.

btw, i assume, it could be implemented as a scheme

it probably can

Where is the current MAKE-TICKS source, by the way?

Posting to you privately.

I was looking for it too. What is this function supposed to do?

Is it timer related?

no, it simply makes a shape block with tick lines for sliders, gradient 
bars and the rgb spectrum viewer. it will be used in more places 
than it currently is in use.

Yes, fairly recently we saw those slider demos with ruler marks on 
them.

.. which is where make-ticks was used.

essentially MAKE-TICKS [3 1 2] would draw something like:

| . . : . . | . . : . . |

Woooh, it means..., nothing to me :-)

your clock on the wall probably has something similar. (if it's an 
analog clock) :-)

Anton, the --do bug is known, cross-platform (not just Linux), and 
part of a half-dozen bugs that can be fixed by rewriting one function. 
It's the next R3 thing on my todo list, when I get the chance. I'm 
swamped with work at the moment.

:-) I thought it is Braile letters :-)

BrianH, cool, that it's next on your todo list - glad you've noticed.

User datatypes can't add new syntax.

http://rebol.hmkdesign.dk/files/r3/gui/106.png

Make-ticks was used in the 5 sliders at the top.

I've just been busy lately. Carl fixed/documented a lot of things 
in alpha 37 for me, but I'm in crunch time at work now. Soon.

Henrik, I advise not spending the energy lobbying for the new datatype. 
Just implement the "counter" algorithm as optimally as you can and 
move on.

Sorry, I think there's too much in this to pass it up. I think this 
would be very useful.

Ok, sliders, rulers, analog clocks... anything else?

Aside from the syntax, this could be done as a user-defined datatype. 
Or it could be done as an API.

Anywhere you want to count with varying base on multiple numbers 
and act on it. I've run into this numerous times.

BrianH, are there docs anywhere on user defined datatypes yet? Limitations?

Just discussions, but I know what the limitations are.

Henrik, I'll have to think more on it.

Steeve, where was your disk-block scheme source?

http://sites.google.com/site/rebolish/

thanks. maybe it's better to implement it as a scheme anyway.

I'm confused on your proposal as wel Henrik. A concrete example would 
really help, since it's a complex concept.

I think I'll wait. I've discovered some problems with the idea, which 
makes it less useful than I thought it would be.