[etoys-dev] Re: repeat-tile

Bert Freudenberg bert at freudenbergs.de
Fri Apr 9 11:48:55 EDT 2010

On 09.04.2010, at 17:37, K. K. Subramaniam wrote:
> On Thursday 08 April 2010 10:32:18 pm Bert Freudenberg wrote:
>> On 08.04.2010, at 18:52, K. K. Subramaniam wrote:
>>> On Thursday 08 April 2010 02:47:13 pm Bert Freudenberg wrote:
>>>> In fact, turtle graphics might be the one intrinsically useful
>>>> application of the repeat tile. If that is so, how about moving it to
>>>> the pen category?
>>> Repeat is convenient outside of pen drawing.
>> Do you have an example?
> A couple of them.
> I have seen kids drag turnBy:5 tiles multiple times into a script, then try to 
> use the repeat tile before they stumble on the fact that repeat 5 turnBy: 5 is 
> same as turnBy: 25. Understanding angular magnitudes seems to take more 
> 'cooking' time than that for linear magnitudes. Is it because one has to run 
> one's eye over 'empty space' to gage angles? I don't know.

That's more of a mis-use than use, right?

> When placing elements along a circle, it is easier to use repeat tile than to 
> dup individual tiles.
>    self heading: 0.
>    12 timesRepeat: [ self dosomething. self turnBy: 30 ].
> or
>   self heading:  0.
>   60 timesRepeat: [ self dosomething. self turnBy: 6 ].

This sounds pretty equivalent in spirit to turtle graphics to me (even if you're placing objects and not just marks).

In any case the discussion showed repeat is too useful to remove or even to hide. But moving it to the pen category seems like win-win to me. You still can use it for anything else but it would encourage to use it with pen drawings.

- Bert -

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