A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category 'enumerating') ----- findFirst: aBlock - "Return the index of my first element for which aBlock evaluates as true."
+ ^ self findFirst: aBlock startingAt: 1! - | index | - index := 0. - [(index := index + 1) <= self size] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added: + ----- Method: SequenceableCollection>>findFirst:ifNone: (in category 'enumerating') ----- + findFirst: aBlock ifNone: anotherBlock + + ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added: + ----- Method: SequenceableCollection>>findFirst:startingAt: (in category 'enumerating') ----- + findFirst: aBlock startingAt: minIndex + + ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added: + ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in category 'enumerating') ----- + findFirst: aBlock startingAt: minIndex ifNone: anotherBlock + "Return the index of my first element with index >= minIndex for which aBlock evaluates as true. If no element is found, return the value of anotherBlock." + + | index | + index := minIndex - 1. + [(index := index + 1) <= self size] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category 'enumerating') ----- findLast: aBlock - "Return the index of my last element for which aBlock evaluates as true."
+ ^ self findLast: aBlock startingAt: 1! - | index | - index := self size + 1. - [(index := index - 1) >= 1] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added: + ----- Method: SequenceableCollection>>findLast:ifNone: (in category 'enumerating') ----- + findLast: aBlock ifNone: anotherBlock + + ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category 'enumerating') ----- + findLast: aBlock startingAt: minIndex - findLast: aBlock startingAt: i - "Return the index of my last element with index >= i for which aBlock evaluates as true."
+ ^ self findLast: aBlock startingAt: minIndex ifNone: [0]! - | index | - index := self size + 1. - [(index := index - 1) >= i] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added: + ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in category 'enumerating') ----- + findLast: aBlock startingAt: minIndex ifNone: anotherBlock + "Return the index of my last element with index >= minIndex for which aBlock evaluates as true. If no element is found, return the value of anotherBlock." + + | index | + index := self size + 1. + [(index := index - 1) >= minIndex] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category 'enumerating') ----- findFirst: aBlock
- "Return the index of my first element for which aBlock evaluates as true."
- ^ self findFirst: aBlock startingAt: 1!
- | index |
- index := 0.
- [(index := index + 1) <= self size] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category 'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
- ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex
- ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
- "Return the index of my first element with index >= minIndex for which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
- | index |
- index := minIndex - 1.
- [(index := index + 1) <= self size] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category 'enumerating') ----- findLast: aBlock
- "Return the index of my last element for which aBlock evaluates as true."
- ^ self findLast: aBlock startingAt: 1!
- | index |
- index := self size + 1.
- [(index := index - 1) >= 1] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category 'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
- ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category 'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock evaluates as true."
- ^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
- | index |
- index := self size + 1.
- [(index := index - 1) >= i] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
- "Return the index of my last element with index >= minIndex for which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
- | index |
- index := self size + 1.
- [(index := index - 1) >= minIndex] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ anotherBlock value!
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock
- "Return the index of my first element for which aBlock evaluates as
true."
- ^ self findFirst: aBlock startingAt: 1!
- | index |
- index := 0.
- [(index := index + 1) <= self size] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
- ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
- ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
- "Return the index of my first element with index >= minIndex for
which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
- | index |
- index := minIndex - 1.
- [(index := index + 1) <= self size] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock
- "Return the index of my last element for which aBlock evaluates as
true."
- ^ self findLast: aBlock startingAt: 1!
- | index |
- index := self size + 1.
- [(index := index - 1) >= 1] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
- ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock
evaluates as true."
- ^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
- | index |
- index := self size + 1.
- [(index := index - 1) >= i] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
- "Return the index of my last element with index >= minIndex for which
aBlock evaluates as true. If no element is found, return the value of anotherBlock."
- | index |
- index := self size + 1.
- [(index := index - 1) >= minIndex] whileTrue:
[(aBlock value: (self at: index)) ifTrue: [^index]].- ^ anotherBlock value!
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization. Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
Best, Christoph
________________________________ Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock
"Return the index of my first element for which aBlock evaluates astrue."
^ self findFirst: aBlock startingAt: 1!
| index |index := 0.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my first element with index >= minIndex forwhich aBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := minIndex - 1.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock
"Return the index of my last element for which aBlock evaluates astrue."
^ self findLast: aBlock startingAt: 1!
| index |index := self size + 1.[(index := index - 1) >= 1] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
"Return the index of my last element with index >= i for which aBlockevaluates as true."
^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
| index |index := self size + 1.[(index := index - 1) >= i] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my last element with index >= minIndex for whichaBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := self size + 1.[(index := index - 1) >= minIndex] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!
Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock - "Return the index of my first element for which aBlock evaluates as
true."
+ ^ self findFirst: aBlock startingAt: 1! - | index | - index := 0. - [(index := index + 1) <= self size] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
+ ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
+ ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my first element with index >= minIndex for
which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := minIndex - 1. + [(index := index + 1) <= self size] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock - "Return the index of my last element for which aBlock evaluates as
true."
+ ^ self findLast: aBlock startingAt: 1! - | index | - index := self size + 1. - [(index := index - 1) >= 1] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
+ ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock
evaluates as true."
+ ^ self findLast: aBlock startingAt: minIndex ifNone: [0]! - | index | - index := self size + 1. - [(index := index - 1) >= i] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my last element with index >= minIndex for which
aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := self size + 1. + [(index := index - 1) >= minIndex] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
and introduction of non-jittable comparison.
What are you referring to?
Best, Christoph
________________________________ Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz
Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock
"Return the index of my first element for which aBlock evaluates astrue."
^ self findFirst: aBlock startingAt: 1!
| index |index := 0.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my first element with index >= minIndex forwhich aBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := minIndex - 1.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock
"Return the index of my last element for which aBlock evaluates astrue."
^ self findLast: aBlock startingAt: 1!
| index |index := self size + 1.[(index := index - 1) >= 1] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
"Return the index of my last element with index >= i for which aBlockevaluates as true."
^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
| index |index := self size + 1.[(index := index - 1) >= i] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my last element with index >= minIndex for whichaBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := self size + 1.[(index := index - 1) >= minIndex] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!
Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
That's a possible way, but there's an even better one: put the actual implementation into #findFirst:startingAt:, and let #findFirst:startingAt:ifAbsent: use it. Just like how it's done in the #indexOf:* methods.
and introduction of non-jittable comparison.
What are you referring to?
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Another possible optimization in #findFirst: is to store #size in a temporary instead of accessing it in each iteration.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
_
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock - "Return the index of my first element for which aBlock evaluates as
true."
+ ^ self findFirst: aBlock startingAt: 1! - | index | - index := 0. - [(index := index + 1) <= self size] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
+ ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
+ ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my first element with index >= minIndex for
which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := minIndex - 1. + [(index := index + 1) <= self size] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock - "Return the index of my last element for which aBlock evaluates as
true."
+ ^ self findLast: aBlock startingAt: 1! - | index | - index := self size + 1. - [(index := index - 1) >= 1] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
+ ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock
evaluates as true."
+ ^ self findLast: aBlock startingAt: minIndex ifNone: [0]! - | index | - index := self size + 1. - [(index := index - 1) >= i] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my last element with index >= minIndex for which
aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := self size + 1. + [(index := index - 1) >= minIndex] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Wow, this is interesting. However, I found out it is even faster to use #to:do: (4.2 ms vs. 5.19 ms). I will send this soon to the inbox.
Just one other question before: I just discovered that we have #detect:ifNone: and also #find:ifNone: and #findBinary:ifNone:. #ifAbsent: rather appears to go with #at:, i. e. lookup operations, whereas #ifNone: goes with search operations. Are you still sure that we shouldn't name the thing #findFirst:ifNone:?
Best, Christoph
________________________________ Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 15:10:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz
Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
That's a possible way, but there's an even better one: put the actual implementation into #findFirst:startingAt:, and let #findFirst:startingAt:ifAbsent: use it. Just like how it's done in the #indexOf:* methods.
and introduction of non-jittable comparison.
What are you referring to?
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Another possible optimization in #findFirst: is to store #size in a temporary instead of accessing it in each iteration.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
_
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock
"Return the index of my first element for which aBlock evaluates astrue."
^ self findFirst: aBlock startingAt: 1!
| index |index := 0.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my first element with index >= minIndex forwhich aBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := minIndex - 1.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock
"Return the index of my last element for which aBlock evaluates astrue."
^ self findLast: aBlock startingAt: 1!
| index |index := self size + 1.[(index := index - 1) >= 1] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
"Return the index of my last element with index >= i for which aBlockevaluates as true."
^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
| index |index := self size + 1.[(index := index - 1) >= i] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my last element with index >= minIndex for whichaBlock evaluates as true. If no element is found, return the value of anotherBlock."
| index |index := self size + 1.[(index := index - 1) >= minIndex] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!
Le lun. 17 févr. 2020 à 19:14, Thiede, Christoph < Christoph.Thiede@student.hpi.uni-potsdam.de> a écrit :
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because
it has more type information available.
Wow, this is interesting. However, I found out it is even faster to use #to:do: (4.2 ms vs. 5.19 ms). I will send this soon to the inbox.
Just one other question before: I just discovered that we have #detect:ifNone: and also #find:ifNone: and #findBinary:ifNone:. #ifAbsent: rather appears to go with #at:, i. e. lookup operations, whereas #ifNone: goes with search operations. Are you still sure that we shouldn't name the thing #findFirst:ifNone:?
I think that you are right
indexOf: anElement ifAbsent: ... is like at: aKey ifAbsent: ... (anElement is absent).
But when we provide a predicate, we might prefer ifNone: (none matches the predicate)
Best,
Christoph
*Von:* Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu *Gesendet:* Montag, 17. Februar 2020 15:10:10 *An:* The general-purpose Squeak developers list *Betreff:* Re: [squeak-dev] The Inbox: Collections-ct.875.mcz
Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to
avoid duplication.
That's a possible way, but there's an even better one: put the actual implementation into #findFirst:startingAt:, and let #findFirst:startingAt:ifAbsent: use it. Just like how it's done in the #indexOf:* methods.
and introduction of non-jittable comparison.
What are you referring to?
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Another possible optimization in #findFirst: is to store #size in a temporary instead of accessing it in each iteration.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im
Auftrag von Levente Uzonyi leves@caesar.elte.hu
Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I
think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner.
Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost
does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk
methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these
methods
were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks
somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
_
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im
Auftrag von Levente Uzonyi leves@caesar.elte.hu
Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I
think
#ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the
performance
impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock
"Return the index of my first element for which aBlockevaluates as
true."
^ self findFirst: aBlock startingAt: 1!
| index |index := 0.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in
category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in
category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!Item was added:
- ----- Method:
SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my first element with index >= minIndexfor
which aBlock evaluates as true. If no element is found, return the
value of
anotherBlock."
| index |index := minIndex - 1.[(index := index + 1) <= self size] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock
"Return the index of my last element for which aBlockevaluates as
true."
^ self findLast: aBlock startingAt: 1!
| index |index := self size + 1.[(index := index - 1) >= 1] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in
category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in
category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
"Return the index of my last element with index >= i forwhich aBlock
evaluates as true."
^ self findLast: aBlock startingAt: minIndex ifNone: [0]!
| index |index := self size + 1.[(index := index - 1) >= i] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ 0!Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone:
(in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
"Return the index of my last element with index >= minIndexfor which
aBlock evaluates as true. If no element is found, return the value
of
anotherBlock."
| index |index := self size + 1.[(index := index - 1) >= minIndex] whileTrue:[(aBlock value: (self at: index)) ifTrue: [^index]].^ anotherBlock value!
Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Wow, this is interesting. However, I found out it is even faster to use #to:do: (4.2 ms vs. 5.19 ms). I will send this soon to the inbox.
Just one other question before: I just discovered that we have #detect:ifNone: and also #find:ifNone: and #findBinary:ifNone:. #ifAbsent: rather appears to go with #at:, i. e. lookup operations, whereas #ifNone: goes with search operations. Are you still sure that we shouldn't name the thing #findFirst:ifNone:?
I don't have #find:ifNone: in my image. SequenceableCollection understands #detect:ifNone:, #findBinary:ifNone:, and #findBinaryIndex:ifNone:. If you search for *ifNone: and *ifAbsent:, you'll find that the latter is more common, but seeing the number of implementors of these methods, I suppose it boils down to personal preference.
Levente
Best, Christoph
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 15:10:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
That's a possible way, but there's an even better one: put the actual implementation into #findFirst:startingAt:, and let #findFirst:startingAt:ifAbsent: use it. Just like how it's done in the #indexOf:* methods.
and introduction of non-jittable comparison.
What are you referring to?
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Another possible optimization in #findFirst: is to store #size in a temporary instead of accessing it in each iteration.
Levente
Best, Christoph
_
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
_
_
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Levente Uzonyi leves@caesar.elte.hu Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits@source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock - "Return the index of my first element for which aBlock evaluates as
true."
+ ^ self findFirst: aBlock startingAt: 1! - | index | - index := 0. - [(index := index + 1) <= self size] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
+ ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
+ ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my first element with index >= minIndex for
which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := minIndex - 1. + [(index := index + 1) <= self size] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock - "Return the index of my last element for which aBlock evaluates as
true."
+ ^ self findLast: aBlock startingAt: 1! - | index | - index := self size + 1. - [(index := index - 1) >= 1] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
+ ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock
evaluates as true."
+ ^ self findLast: aBlock startingAt: minIndex ifNone: [0]! - | index | - index := self size + 1. - [(index := index - 1) >= i] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my last element with index >= minIndex for which
aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := self size + 1. + [(index := index - 1) >= minIndex] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Hi Levente,
whoops, this had escaped my attention, sorry! Anyway, there is (almost 2 year old :D) Collections-ct.877 in the inbox - do you think we can merge it like this or have you got any further tips for me? :-)
Best, Christoph
--- Sent from Squeak Inbox Talk
On 2020-02-17T20:23:37+01:00, leves@caesar.elte.hu wrote:
Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Wow, this is interesting. However, I found out it is even faster to use #to:do: (4.2 ms vs. 5.19 ms). I will send this soon to the inbox.
Just one other question before: I just discovered that we have #detect:ifNone: and also #find:ifNone: and #findBinary:ifNone:. #ifAbsent: rather appears to go with #at:, i. e. lookup operations, whereas #ifNone: goes with search operations. Are you still sure that we shouldn't name the thing #findFirst:ifNone:?
I don't have #find:ifNone: in my image. SequenceableCollection understands #detect:ifNone:, #findBinary:ifNone:, and #findBinaryIndex:ifNone:. If you search for *ifNone: and *ifAbsent:, you'll find that the latter is more common, but seeing the number of implementors of these methods, I suppose it boils down to personal preference.
Levente
Best, Christoph
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im Auftrag von Levente Uzonyi <leves at caesar.elte.hu> Gesendet: Montag, 17. Februar 2020 15:10:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Mon, 17 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
alright, I'll try to measure and optimize them again.
Two things I saw and you didn't mention are block creation
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
That's a possible way, but there's an even better one: put the actual implementation into #findFirst:startingAt:, and let #findFirst:startingAt:ifAbsent: use it. Just like how it's done in the #indexOf:* methods.
and introduction of non-jittable comparison.
What are you referring to?
The current Spur VM makes x >= 1 about 1.5x faster than x >= y, because it has more type information available.
Another possible optimization in #findFirst: is to store #size in a temporary instead of accessing it in each iteration.
Levente
Best, Christoph
_
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im Auftrag von Levente Uzonyi <leves at caesar.elte.hu> Gesendet: Montag, 17. Februar 2020 01:00:11 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz Hi Christoph,
On Sun, 16 Feb 2020, Thiede, Christoph wrote:
Hi Levente,
thanks for the suggestions.
And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Agreed :-)
I suggest keeping the all method comments
Personally, I see little value in documenting a one-liner. Documentation is useful for explaining and optimized method that does not provide the typical Smalltalk readability. Plus, they all need to be maintained ...
If one sees #findLast: being sent somewhere, and one doesn't know what it does, with your changes, it means looking up the implementors three times to get to the actual implementation and comment.
measuring the performance impact of the rewrite.
What is the critical point here? Of course, the stack will be a little higher, but the asymptotic cost does not change. We only evaluate anotherBlock at the end instead of returning 0.
Two things I saw and you didn't mention are block creation and introduction of non-jittable comparison.
Please do not misunderstand me: I honor optimizing critical Smalltalk methods, but I always strive to avoid premature optimization.
In my opinion, generic library methods like these should be optimized by definition.
Calling premature optimization means that you assume that if these methods were written in a more optimal way, then their complexity and/or legibility would be worse. Have a look at #indexOf:*, and you'll see that's not the case.
Should we maybe establish to practice to store such benchmarks somewhere in the trunk so that not every willing contributor needs to write them again?
I think methods like these don't change often enough (presumably they never change) to justify storing benchmarks for them.
Levente
Best, Christoph
_
_
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im Auftrag von Levente Uzonyi <leves at caesar.elte.hu> Gesendet: Sonntag, 16. Februar 2020 22:47:10 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz And one more thing: These method resemble #indexOf:* methods, so I think #ifAbsent: is a better choice than #ifNone:.
Levente
On Sun, 16 Feb 2020, Levente Uzonyi wrote:
Hi Christoph,
I suggest keeping the all method comments, and measuring the performance impact of the rewrite.
Levente
On Sun, 16 Feb 2020, commits at source.squeak.org wrote:
A new version of Collections was added to project The Inbox: http://source.squeak.org/inbox/Collections-ct.875.mcz
==================== Summary ====================
Name: Collections-ct.875 Author: ct Time: 16 February 2020, 3:32:23.116 pm UUID: 61ea773b-1408-c040-a712-09238ee6fe2f Ancestors: Collections-topa.873
Extends and realigns version of #findFirst: and #findLast:.
=============== Diff against Collections-topa.873 ===============
Item was changed: ----- Method: SequenceableCollection>>findFirst: (in category
'enumerating') -----
findFirst: aBlock - "Return the index of my first element for which aBlock evaluates as
true."
+ ^ self findFirst: aBlock startingAt: 1! - | index | - index := 0. - [(index := index + 1) <= self size] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:ifNone: (in category
'enumerating') -----
- findFirst: aBlock ifNone: anotherBlock
+ ^ self findFirst: aBlock startingAt: 1 ifNone: anotherBlock!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt: (in category
'enumerating') -----
- findFirst: aBlock startingAt: minIndex
+ ^ self findFirst: aBlock startingAt: minIndex ifNone: [0]!
Item was added:
- ----- Method: SequenceableCollection>>findFirst:startingAt:ifNone: (in
category 'enumerating') -----
- findFirst: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my first element with index >= minIndex for
which aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := minIndex - 1. + [(index := index + 1) <= self size] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
Item was changed: ----- Method: SequenceableCollection>>findLast: (in category
'enumerating') -----
findLast: aBlock - "Return the index of my last element for which aBlock evaluates as
true."
+ ^ self findLast: aBlock startingAt: 1! - | index | - index := self size + 1. - [(index := index - 1) >= 1] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:ifNone: (in category
'enumerating') -----
- findLast: aBlock ifNone: anotherBlock
+ ^ self findLast: aBlock startingAt: 1 ifNone: anotherBlock!
Item was changed: ----- Method: SequenceableCollection>>findLast:startingAt: (in category
'enumerating') -----
- findLast: aBlock startingAt: minIndex
- findLast: aBlock startingAt: i
- "Return the index of my last element with index >= i for which aBlock
evaluates as true."
+ ^ self findLast: aBlock startingAt: minIndex ifNone: [0]! - | index | - index := self size + 1. - [(index := index - 1) >= i] whileTrue: - [(aBlock value: (self at: index)) ifTrue: [^index]]. - ^ 0!
Item was added:
- ----- Method: SequenceableCollection>>findLast:startingAt:ifNone: (in
category 'enumerating') -----
- findLast: aBlock startingAt: minIndex ifNone: anotherBlock
+ "Return the index of my last element with index >= minIndex for which
aBlock evaluates as true. If no element is found, return the value of anotherBlock."
+ | index | + index := self size + 1. + [(index := index - 1) >= minIndex] whileTrue: + [(aBlock value: (self at: index)) ifTrue: [^index]]. + ^ anotherBlock value!
On 2020-02-17, at 2:36 AM, Thiede, Christoph Christoph.Thiede@student.hpi.uni-potsdam.de wrote:
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
Please don't. This is ugly beyond any level of acceptability
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim Useful random insult:- On permanent leave of absence from his senses.
Don't worry, I never really liked it myself 😊
________________________________ Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von tim Rowledge tim@rowledge.org Gesendet: Montag, 17. Februar 2020 19:32:03 An: The general-purpose Squeak developers list Betreff: Re: [squeak-dev] The Inbox: Collections-ct.875.mcz
On 2020-02-17, at 2:36 AM, Thiede, Christoph Christoph.Thiede@student.hpi.uni-potsdam.de wrote:
You mean that "ifNone: [0]"? One could replace it with "ifNone: 0" to avoid duplication.
Please don't. This is ugly beyond any level of acceptability
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim Useful random insult:- On permanent leave of absence from his senses.
squeak-dev@lists.squeakfoundation.org
-
christoph.thiede＠student.hpi.uni-potsdam.de -
commits＠source.squeak.org -
Levente Uzonyi -
Nicolas Cellier -
Thiede, Christoph
-
tim Rowledge