Hi. сб, 28 апр. 2018 г., 1:26 Richard Sargent < richard.sarg...@gemtalksystems.com>:
> On Fri, Apr 27, 2018 at 3:58 PM, Esteban A. Maringolo < > emaring...@gmail.com> wrote: > >> oh, you were talking about how te VM views the object, >> I was thinking in terms of how the compiler sees the text. >> >> So I'm talking about literals "syntax". >> >> Thanks anyway for the "trick" :) >> > > Another common technique is a "once block". Teach Block how to evaluate > itself once and to use its cached result the next time. > We have similar mechanizm in Pharo. Look at http://dionisiydk.blogspot.fr/2016/07/magic-with-pharo-reflectivity.html > It's not as fast as a literal, but it is a pretty effective way to have a > clean implementation with as complex code as one could wish. > Clear the cache when saving the image or at image start up or ... whenever > seems good (such as when you change the implementation of what was cached. > > e.g. > [Dictionary new > at: #a put: self something; > at: #b put: self somethingElse; > yourself] > once > > > >> >> On 27/04/2018 16:34, Clément Bera wrote: >> > The guy who asked the question said: "...when you want to shorten some >> > object initialization" >> > >> > Using ClassVariable is an alternative way to shorten object >> > initialization, reading a ClassVariable is almost the same performance >> > as reading a literal, so that looked like a good alternative to me. Both >> > the ClassVariable and the literal have the same issues (same object so >> > if you mutate it you have to deal with it). >> > >> > But yes, it's not a new literal. >> > >> > For new literals, you can extend the compiler or hard patch thing: >> > >> > MyClass>>foo >> > ^ #bar >> > >> > (MyClass>>#foo) literalAt: ((MyClass>>#foo) literals indexOf: #bar) put: >> > Set new. >> > >> > MyClass new foo >> > >> >>>> a Set () >> > >> > Obviously it depends what you mean by literal, the latter code uses the >> > literal bytecode instruction, which does not make the pushed object a >> > literal object... >> >> >> -- >> Esteban A. Maringolo >> >> >
