Re: [Pharo-users] [ANN] Iterators
Hi Julien, nice work! Could you please tell how your approach is related to transducers from the user perspective and technically? (https://github.com/Pharophile/Transducers) Your example suggests that the API is quite similar to the data flow API of transducers. Let me show your example using transducers. result := (#+ init: 0) <~ [:x | x * 2] map <~ #(1 2 3). OrderedCollection with: result. Or the more classical way: result := #(1, 2, 3) transduce: [:x | x * 2] map reduce: #+ init: 0. OrderedCollection with: result. Best regards, Steffen
[Pharo-users] Putting checkboxes in ListPresenter
Guys,
I am learning this new "spec" thing. I created a simple Spec "list" object
with the following code:
arbitraryList := ListPresenter new.
arbitraryList
items: #('one' 'two' 'three' 'four. . .');
title: 'Arbitrary list'.
arbitraryList openWithSpec.
Which creates a simple list like follows:
https://steverstuff.s3.amazonaws.com/arbitrary_list.png
Is there any way to make a SpecPresenter object with an arbitrary list of
checkboxes? Kind of like a check-off list?
What is the best way of doing this? Should I put checkbox objects in the
"items:" selector? Or is there another way to do it?
Please forgive the naive question.
Re: [Pharo-users] Putting checkboxes in ListPresenter
Hi Steve.
This is not at all a naive question. This is partly showned in the advance
part of spec, and as it said: "ListModel can show more than just text, it
can also visualize any kind of widget."
Here is how you could do a static list of checkBox:
In your initializeWidget method, create your checkbox:
item1 := self newCheckBox label: 'label1'; help: 'help1'; yourself.
item2 := self newCheckBox label: 'label2; help: 'help2'; yourself.
item3 := self newCheckBox label: 'label3'; help: 'help3'; yourself.
You can then create and display your list:
projectList := (self instantiate: ListPresenter)
displayBlock: [ :x | x buildWithSpec ];
items: {item1 . item2 . item3};
yourself.
And your defaultSpec can be as simple as:
defaultSpec [
^ SpecLayout composed
add: #projectList;
yourself
]
Hope this helps.
Renaud
Le sam. 24 août 2019 à 14:53, Steve Quezadas a écrit :
> Guys,
>
> I am learning this new "spec" thing. I created a simple Spec "list" object
> with the following code:
> arbitraryList := ListPresenter new.
> arbitraryList
>items: #('one' 'two' 'three' 'four. . .');
>title: 'Arbitrary list'.
> arbitraryList openWithSpec.
>
> Which creates a simple list like follows:
> https://steverstuff.s3.amazonaws.com/arbitrary_list.png
>
> Is there any way to make a SpecPresenter object with an arbitrary list of
> checkboxes? Kind of like a check-off list?
>
> What is the best way of doing this? Should I put checkbox objects in the
> "items:" selector? Or is there another way to do it?
>
> Please forgive the naive question.
>
Re: [Pharo-users] [ANN] Iterators
Distinguishing between "pull-based" and "push-based" streams in Smalltalk makes no sense, because do: aBlock [self atEnd] whileFalse: [aBlock value: self next]. is in the same protocol in the ANSI standard as #atEnd and #next, and in most Smalltalk systems it is in Stream. There should never be anything that has #atEnd and #next that doesn't have #do:. In some Smalltalk systems, Stream and Collection both inherit from a common superclass. In GNU Smalltalk, it's called Iterable, and provides, amongst other things stream1 , stream2 stream allSatisfy: filterBlock stream anySatisfy: filterBlock stream collect: transformBlock stream count: filterBlock stream detect: filterBlock stream detect: filterBlock ifNone: exceptionBlock stream do: actionBlock stream do: actionBlock separatedBy: separatorBlock stream fold: combinerBlock stream inject: initial into: combinerBlock stream noneSatisfy: filterBlock stream reject: filterBlock stream select: filterBlock My Smalltalk library does not do that, but it does have an Enumerable class that's somewhat similar (the distinction is that multiple traversal of a Collection must work, but only single traversal of an Enumerable is required), so readStream asEnumerable reject: filterBlock This makes about 257 Enumerable methods available. Combinators are good, but they should fit in with existing naming conventions. *Arbitrary* overloadings are a bad idea. The pipe "|" allows one to chain iterators - The ">" allows one to create a new collection with data transformed through chained iterators - The ">>" allows one to fill an existing collection with data transformed through chained iterators The vertical bar is used in Smalltalk for "or". It would make sense to have MonadicBlock methods for: 'combinators' | other ^[:x | (self value: x) | (other value: x)] and so on. Smalltalk already has a selector that means "concatenation", namely #, so stream1 , stream2 as in GNU Smalltalk would not be too confusing. Similarly, ">" means "greater than", and it would be deeply confusing to use it for some sort of data construction. We would expect stream1 > stream2 iff the future values of stream1 (as a sequence) are lexicographically greater than the future values of stream2 (as a sequence). Or you could argue for "the relative order of two streams is the relative order of their positions if the have the same underlying Collection or file system object, otherwise undefined".
Re: [Pharo-users] Putting checkboxes in ListPresenter
Thank you, Renaud, for explaining that. I am so glad to see that Pharo has
addressed this and made it so simple. I've seen too many UIs that fail on
this kind of thing.
Kudos to those people who created this. You nailed it!
On Sat, Aug 24, 2019, 18:31 Renaud de Villemeur
wrote:
> Hi Steve.
>
> This is not at all a naive question. This is partly showned in the advance
> part of spec, and as it said: "ListModel can show more than just text, it
> can also visualize any kind of widget."
>
> Here is how you could do a static list of checkBox:
> In your initializeWidget method, create your checkbox:
>
> item1 := self newCheckBox label: 'label1'; help: 'help1'; yourself.
> item2 := self newCheckBox label: 'label2; help: 'help2'; yourself.
> item3 := self newCheckBox label: 'label3'; help: 'help3'; yourself.
>
> You can then create and display your list:
>
> projectList := (self instantiate: ListPresenter)
> displayBlock: [ :x | x buildWithSpec ];
> items: {item1 . item2 . item3};
> yourself.
>
>
> And your defaultSpec can be as simple as:
>
> defaultSpec [
> ^ SpecLayout composed
> add: #projectList;
> yourself
> ]
>
> Hope this helps.
> Renaud
>
>
> Le sam. 24 août 2019 à 14:53, Steve Quezadas a
> écrit :
>
>> Guys,
>>
>> I am learning this new "spec" thing. I created a simple Spec "list"
>> object with the following code:
>> arbitraryList := ListPresenter new.
>> arbitraryList
>>items: #('one' 'two' 'three' 'four. . .');
>>title: 'Arbitrary list'.
>> arbitraryList openWithSpec.
>>
>> Which creates a simple list like follows:
>> https://steverstuff.s3.amazonaws.com/arbitrary_list.png
>>
>> Is there any way to make a SpecPresenter object with an arbitrary list of
>> checkboxes? Kind of like a check-off list?
>>
>> What is the best way of doing this? Should I put checkbox objects in the
>> "items:" selector? Or is there another way to do it?
>>
>> Please forgive the naive question.
>>
>
