Hi David, hi Marcel,

these are very good points. Please find the next iteration of the patch attached. Instead of ' (n)', I decided on '^n' (common mathm. multiset notation) as I believe that even more brackets would be too confusing. Many printStrings already use them to display a hash or something else.

What do you think? :-)

Best,
Christoph

=============== Summary ===============

Change Set:        Bag printString
Date:            26 February 2022
Author:            Christoph Thiede

This changeset customizes the Bag printString to no longer emit every occurence of each element repeatedly.

Example:
    {10 @ 10. 10 @ 10. 20 @ 20. 20 @ 20. 20 @ 20. 30 @ 30. 30 @ 30. 40 @ 40} asBag. 'a Bag(10 at 10^2 20 at 20^3 30 at 30^2 40 at 40)'.

Thanks to Robert (rhi) for the hint!

Revision: Do not print the number for items with 1 occurence. Instead of '->', denote counts by '^', following the mathematical notiation of multisets.

=============== Diff ===============

Bag>>printElementsOn: {printing} · ct 3/25/2022 20:21
+ printElementsOn: aStream
+ 
+     aStream nextPut: $(.
+     contents size > 100
+         ifTrue: [aStream nextPutAll: 'size '.
+             self size printOn: aStream]
+         ifFalse: [contents keysInOrder
+             do: [:key | | count |
+                 aStream print: key.
+                 (count := contents at: key) > 1 ifTrue: [
+                     aStream
+                         nextPut: $^;
+                          print: count]]
+             separatedBy: [aStream space]].
+     aStream nextPut: $)

BagTest>>testPrintString {tests} · ct 3/25/2022 20:24
+ testPrintString
+ 
+     | bag |
+     bag := Bag new.
+     bag add: $1 withOccurrences: 5.
+     bag add: '2' withOccurrences: 1.
+     bag add: self withOccurrences: 3.
+     
+     self assert: 'a Bag(BagTest>>#testPrintString^3 ''2'' $1^5)' equals: bag printString.

Dictionary>>printElementsOn: {printing} · ct 2/26/2022 20:28 (changed)
printElementsOn: aStream 
    aStream nextPut: $(.
    self size > 100
        ifTrue: [aStream nextPutAll: 'size '.
            self size printOn: aStream]
        ifFalse: [self keysInOrder
                do: [:key | aStream print: key;
                         nextPutAll: '->';                
-                          print: (self at: key);
-                          space]].
+                          print: (self at: key)]
+                 separatedBy: [aStream space]].
    aStream nextPut: $)

---
Sent from Squeak Inbox Talk

On 2022-02-28T09:17:04+01:00, marcel.taeumel at hpi.de wrote:

> Hi Christoph --
> 
> I have to agree with Dave. Can we find a threshold when it makes sense to show the counts of each element? Maybe drop the "1" entirely and only show "->n" for n > 1? Maybe don't use "->" but parentheses? And maybe check with objects that have a more complex printString on their own. Hmm...
> 
> aBag(10 at 10 (2) 20 at 20 (3) ...)
> 
> (Also make sure that the printString is kind of as fast as before. Thanks.)
> 
> Best,
> Marcel
> Am 26.02.2022 23:08:06 schrieb David T. Lewis <lewis at mail.msen.com>:
> This seems easier to read for the case of a Bag containing
> many copies of the same entry, and harder to read for the
> case of a Bag containing mostly different entries. I am not
> sure which is the more common scenario.
> 
> The original printString hides the implementation, which seems
> like a good thing.
> 
> Either approach would be fine for me, although I think I slightly
> prefer the original version.
> 
> Dave
> 
> On Sat, Feb 26, 2022 at 08:49:48PM +0100, christoph.thiede at student.hpi.uni-potsdam.de wrote:
> > =============== Summary ===============
> >
> > Change Set:????????Bag printString
> > Date:????????????26 February 2022
> > Author:????????????Christoph Thiede
> >
> > This changeset customizes the Bag printString to no longer emit every occurence of each element repeatedly.
> >
> > Example:
> > ????{10 @ 10. 10 @ 10. 20 @ 20. 20 @ 20. 20 @ 20. 30 @ 30. 30 @ 30. 40 @ 40} asBag. 'a Bag(10 at 10->2 20 at 20->3 30 at 30->2 40 at 40->1)'.
> >
> > Thanks to Robert (rhi) for the hint!
> >
> > =============== Diff ===============
> >
> > Bag>>printElementsOn: {printing} ? ct 2/26/2022 20:26
> > + printElementsOn: aStream
> > +
> > + ????contents printElementsOn: aStream.
> >
> > BagTest>>testPrintString {tests} ? ct 2/26/2022 20:25
> > + testPrintString
> > +
> > + ????| bag |
> > + ????bag := Bag new.
> > + ????bag add: '1' withOccurrences: 5.
> > + ????bag add: '2' withOccurrences: 1.
> > + ????bag add: '3' withOccurrences: 3.
> > + ????
> > + ????self assert: 'a Bag(''1''->5 ''2''->1 ''3''->3)' equals: bag printString.
> >
> > Dictionary>>printElementsOn: {printing} ? ct 2/26/2022 20:28 (changed)
> > printElementsOn: aStream
> > ????aStream nextPut: $(.
> > ????self size > 100
> > ????????ifTrue: [aStream nextPutAll: 'size '.
> > ????????????self size printOn: aStream]
> > ????????ifFalse: [self keysInOrder
> > ????????????????do: [:key | aStream print: key;
> > ???????????????????????? nextPutAll: '->';????????????????
> > - ???????????????????????? print: (self at: key);
> > - ???????????????????????? space]].
> > + ???????????????????????? print: (self at: key)]
> > + ????????????????separatedBy: [aStream space]].
> > ????aStream nextPut: $)
> >
> > ---
> > Sent from Squeak Inbox Talk
> > ["Bag printString.1.cs"]
> 
> >
> 
> 
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