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Re: [Pharo-dev] memoized vs once

by Igor Stasenko

Because caching are always comes with concerns, like when/where do we want to drop cached results and recalculate them, if needed.. With memoization it seems like there's simply no such concern at all.. meaning that cached data will live forever since created once.. which is never good for dynamic system.. because i spent significant portion of my smalltalk life hunting for leaks and immortal references that you cannot get rid of, because some guy forgot to provide a nice and easy interface or api to get rid of volatile data.. like open files or socket connections, session etc etc.. and now.. let us welcome.. memoization. :) -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

On 26 January 2017 at 01:40, phil(a)highoctane.be <phil(a)highoctane.be> wrote: > Yeah, I get you 100%. > > I wanted to be able to cache or not and have this transparent. > > Memoization in its current form in Pharo is not like I would like to have > it. > > As for the repeating block, I was asking to how you would avoid repeating > in the given code structure. > You asking me rewrite it for your example? unless i missing something (not)obvious here, it can look like this: getIssueCreateMeta "Retrieves the metadata for all types of issues. Fields are expanded" ^ self cache at: #issueCreateMeta ifAbsentPut: [ self getIssueCreateMetaWithExpandKeys: true ] Btw, it is a good question, what are the difference between caching and memoization, besides that google underlines 'memoization' word with thin red curly line while i typing? :) -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

Yeah, I get you 100%. I wanted to be able to cache or not and have this transparent. Memoization in its current form in Pharo is not like I would like to have it. As for the repeating block, I was asking to how you would avoid repeating in the given code structure. Phil On Thu, Jan 26, 2017 at 12:34 AM, Igor Stasenko <siguctua(a)gmail.com> wrote: > > > On 26 January 2017 at 01:23, phil(a)highoctane.be <phil(a)highoctane.be> > wrote: > >> Nothing new, that's the term. >> >> Memoization: After computing a solution to a subproblem, store it in a >> table. Subsequent calls check the table to avoid redoing work. >> >> https://en.wikipedia.org/wiki/Memoization >> >> http://www.cas.mcmaster.ca/~deza/6_Dynamic++.pdf >> >> http://wiki.tcl.tk/10779 >> >> I have been using the method for something else, caching costly REST >> calls. >> >> getIssueCreateMeta >> "Retrieves the metadata for all types of issues. Fields are expanded" >> ^ self isMemoizingMeta >> ifTrue: [ ([ :ignored | self getIssueCreateMetaWithExpandKeys: true ] >> memoizedUsing: self cache ) value: #issueCreateMeta ] >> ifFalse: [ self getIssueCreateMetaWithExpandKeys: true ] >> >> >> using: >> >> cache >> ^ cache ifNil: [cache := LRUCache new maximumWeight: self >> defaultCacheWeight ] >> >> It is nice to see the cache hit rate etc in the inspector. >> >> BTW I am interested to see how one coul dwrite the code above without >> repeating the block. >> Also, :ignored is not used by the method but is the cache key. >> >> > well, for not repeating, its easy, for instance in NativeBoost i just used > expressions like: > > getIssueCreateMeta > ^ self cacheAt: somekey ifAbsentPut: [ some data ] > > which are self-explanatory (i hope) > where somekey could be 'self' or whatever seem fit. > > as for the caching wihoout key, why not just store result of first > evaluation and then use it directly anywhere else? why need to wrap it > with block?? > > data := [some calculation ] value. > > self doSomethingWith: data. > self doSomethingElseWith: data. > self doSomethingElseElseWith: data. > > > voila.. plain programming. Where does memoization need to be coined here? > :) > > Phil >> >> On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> >> wrote: >> >>> #once can be interpreted as 'evaluate it once', >>> >>> but i don't like the #memoized .. it sounds painful to my ears. >>> It sounds like something stinking smeared across my face.. and i always >>> got stuck,confused and lost as the meaning of it always >>> escaping my mind, since it naturally defends itself from any unpleasant >>> thoughts. >>> >>> IMHO, maybe #once is not the best wording for what it does , but >>> #memoizing... yuck.. pardon me. >>> >>> :) >>> >>> >>> -- >>> Best regards, >>> Igor Stasenko. >>> >> >> > > > -- > Best regards, > Igor Stasenko. >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

On 26 January 2017 at 01:33, phil(a)highoctane.be <phil(a)highoctane.be> wrote: > self memoize: #methodThatDoesSomethingLong:. > > would automatically store parameters values as cache keys. No matter how > many such parms. > > No need to have blocks or anything,operations are memoized. > We use blocks for lack of a better way right now I guess. > > Phil > > well, that's something i calling 'caching'.. because if you cashing many results, depending on input data, then it is better to call caching.. but in original example, there's noting like this.. it is just block without arguments.. so, what you going to use as keys for caching evaluation of such block, how do you identify what value(s) are inputs for such block and what not? -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

On 26 January 2017 at 01:23, phil(a)highoctane.be <phil(a)highoctane.be> wrote: > Nothing new, that's the term. > > Memoization: After computing a solution to a subproblem, store it in a > table. Subsequent calls check the table to avoid redoing work. > > https://en.wikipedia.org/wiki/Memoization > > http://www.cas.mcmaster.ca/~deza/6_Dynamic++.pdf > > http://wiki.tcl.tk/10779 > > I have been using the method for something else, caching costly REST calls. > > getIssueCreateMeta > "Retrieves the metadata for all types of issues. Fields are expanded" > ^ self isMemoizingMeta > ifTrue: [ ([ :ignored | self getIssueCreateMetaWithExpandKeys: true ] > memoizedUsing: self cache ) value: #issueCreateMeta ] > ifFalse: [ self getIssueCreateMetaWithExpandKeys: true ] > > > using: > > cache > ^ cache ifNil: [cache := LRUCache new maximumWeight: self > defaultCacheWeight ] > > It is nice to see the cache hit rate etc in the inspector. > > BTW I am interested to see how one coul dwrite the code above without > repeating the block. > Also, :ignored is not used by the method but is the cache key. > > well, for not repeating, its easy, for instance in NativeBoost i just used expressions like: getIssueCreateMeta ^ self cacheAt: somekey ifAbsentPut: [ some data ] which are self-explanatory (i hope) where somekey could be 'self' or whatever seem fit. as for the caching wihoout key, why not just store result of first evaluation and then use it directly anywhere else? why need to wrap it with block?? data := [some calculation ] value. self doSomethingWith: data. self doSomethingElseWith: data. self doSomethingElseElseWith: data. voila.. plain programming. Where does memoization need to be coined here? :) Phil > > On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> > wrote: > >> #once can be interpreted as 'evaluate it once', >> >> but i don't like the #memoized .. it sounds painful to my ears. >> It sounds like something stinking smeared across my face.. and i always >> got stuck,confused and lost as the meaning of it always >> escaping my mind, since it naturally defends itself from any unpleasant >> thoughts. >> >> IMHO, maybe #once is not the best wording for what it does , but >> #memoizing... yuck.. pardon me. >> >> :) >> >> >> -- >> Best regards, >> Igor Stasenko. >> > > -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

self memoize: #methodThatDoesSomethingLong:. would automatically store parameters values as cache keys. No matter how many such parms. No need to have blocks or anything,operations are memoized. We use blocks for lack of a better way right now I guess. Phil On Thu, Jan 26, 2017 at 12:22 AM, Igor Stasenko <siguctua(a)gmail.com> wrote: > result := [ do something long or short or whatever] cached. > > On 26 January 2017 at 01:20, Igor Stasenko <siguctua(a)gmail.com> wrote: > >> >> >> On 26 January 2017 at 01:14, phil(a)highoctane.be <phil(a)highoctane.be> >> wrote: >> >>> If one is doing any dynamic programming, the memoization term is pretty >>> natural. >>> >>> for that purpose, i naturally using 'caching' wording. >> >> >>> https://youtu.be/OQ5jsbhAv_M?t=3m11s >>> >>> Phil >>> >>> On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> >>> wrote: >>> >>>> #once can be interpreted as 'evaluate it once', >>>> >>>> but i don't like the #memoized .. it sounds painful to my ears. >>>> It sounds like something stinking smeared across my face.. and i always >>>> got stuck,confused and lost as the meaning of it always >>>> escaping my mind, since it naturally defends itself from any unpleasant >>>> thoughts. >>>> >>>> IMHO, maybe #once is not the best wording for what it does , but >>>> #memoizing... yuck.. pardon me. >>>> >>>> :) >>>> >>>> >>>> -- >>>> Best regards, >>>> Igor Stasenko. >>>> >>> >>> >> >> >> -- >> Best regards, >> Igor Stasenko. >> > > > > -- > Best regards, > Igor Stasenko. >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

But for caching you have a cache. The whole point of memoization support is to have it easy to do. Look at the bottom of this page: http://wiki.tcl.tk/10981 So if we could have some kind of the same using manipulation of thisContext and/or Slots, it would be nicer. e.g. SomeClass>>#initialize self memoize: #someMethod:andParms:. and bingo, automatic method memoization keyed by the objects passed. That would be better. Phil On Thu, Jan 26, 2017 at 12:20 AM, Igor Stasenko <siguctua(a)gmail.com> wrote: > > > On 26 January 2017 at 01:14, phil(a)highoctane.be <phil(a)highoctane.be> > wrote: > >> If one is doing any dynamic programming, the memoization term is pretty >> natural. >> >> for that purpose, i naturally using 'caching' wording. > > >> https://youtu.be/OQ5jsbhAv_M?t=3m11s >> >> Phil >> >> On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> >> wrote: >> >>> #once can be interpreted as 'evaluate it once', >>> >>> but i don't like the #memoized .. it sounds painful to my ears. >>> It sounds like something stinking smeared across my face.. and i always >>> got stuck,confused and lost as the meaning of it always >>> escaping my mind, since it naturally defends itself from any unpleasant >>> thoughts. >>> >>> IMHO, maybe #once is not the best wording for what it does , but >>> #memoizing... yuck.. pardon me. >>> >>> :) >>> >>> >>> -- >>> Best regards, >>> Igor Stasenko. >>> >> >> > > > -- > Best regards, > Igor Stasenko. >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by phil＠highoctane.be

Nothing new, that's the term. Memoization: After computing a solution to a subproblem, store it in a table. Subsequent calls check the table to avoid redoing work. https://en.wikipedia.org/wiki/Memoization http://www.cas.mcmaster.ca/~deza/6_Dynamic++.pdf http://wiki.tcl.tk/10779 I have been using the method for something else, caching costly REST calls. getIssueCreateMeta "Retrieves the metadata for all types of issues. Fields are expanded" ^ self isMemoizingMeta ifTrue: [ ([ :ignored | self getIssueCreateMetaWithExpandKeys: true ] memoizedUsing: self cache ) value: #issueCreateMeta ] ifFalse: [ self getIssueCreateMetaWithExpandKeys: true ] using: cache ^ cache ifNil: [cache := LRUCache new maximumWeight: self defaultCacheWeight ] It is nice to see the cache hit rate etc in the inspector. BTW I am interested to see how one coul dwrite the code above without repeating the block. Also, :ignored is not used by the method but is the cache key. Phil On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> wrote: > #once can be interpreted as 'evaluate it once', > > but i don't like the #memoized .. it sounds painful to my ears. > It sounds like something stinking smeared across my face.. and i always > got stuck,confused and lost as the meaning of it always > escaping my mind, since it naturally defends itself from any unpleasant > thoughts. > > IMHO, maybe #once is not the best wording for what it does , but > #memoizing... yuck.. pardon me. > > :) > > > -- > Best regards, > Igor Stasenko. >

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

result := [ do something long or short or whatever] cached. On 26 January 2017 at 01:20, Igor Stasenko <siguctua(a)gmail.com> wrote: > > > On 26 January 2017 at 01:14, phil(a)highoctane.be <phil(a)highoctane.be> > wrote: > >> If one is doing any dynamic programming, the memoization term is pretty >> natural. >> >> for that purpose, i naturally using 'caching' wording. > > >> https://youtu.be/OQ5jsbhAv_M?t=3m11s >> >> Phil >> >> On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> >> wrote: >> >>> #once can be interpreted as 'evaluate it once', >>> >>> but i don't like the #memoized .. it sounds painful to my ears. >>> It sounds like something stinking smeared across my face.. and i always >>> got stuck,confused and lost as the meaning of it always >>> escaping my mind, since it naturally defends itself from any unpleasant >>> thoughts. >>> >>> IMHO, maybe #once is not the best wording for what it does , but >>> #memoizing... yuck.. pardon me. >>> >>> :) >>> >>> >>> -- >>> Best regards, >>> Igor Stasenko. >>> >> >> > > > -- > Best regards, > Igor Stasenko. > -- Best regards, Igor Stasenko.

Jan. 25, 2017

Re: [Pharo-dev] memoized vs once

by Igor Stasenko

On 26 January 2017 at 01:14, phil(a)highoctane.be <phil(a)highoctane.be> wrote: > If one is doing any dynamic programming, the memoization term is pretty > natural. > > for that purpose, i naturally using 'caching' wording. > https://youtu.be/OQ5jsbhAv_M?t=3m11s > > Phil > > On Wed, Jan 25, 2017 at 10:30 PM, Igor Stasenko <siguctua(a)gmail.com> > wrote: > >> #once can be interpreted as 'evaluate it once', >> >> but i don't like the #memoized .. it sounds painful to my ears. >> It sounds like something stinking smeared across my face.. and i always >> got stuck,confused and lost as the meaning of it always >> escaping my mind, since it naturally defends itself from any unpleasant >> thoughts. >> >> IMHO, maybe #once is not the best wording for what it does , but >> #memoizing... yuck.. pardon me. >> >> :) >> >> >> -- >> Best regards, >> Igor Stasenko. >> > > -- Best regards, Igor Stasenko.

Jan. 25, 2017