I need to say that this is not a good use case. First and most important is that you should not have deployment switches in your code. Your system should be configured for a special deployment mode not detecting in code. Second but not least important you add references to test classes in your business logic. Usually you do not load test code in a production image. Couldnât resist, sorry Norbert
Am 26.05.2018 um 07:46 schrieb Clément Bera <bera.clement@gmail.com>:
Just mentioning another use-case:
getDatabaseInstance ^ (Production CifTrue: [Database] CifFalse: [MockDatabase]) new
Since I use conditional compilation more often than just precompiling constants.
I don't see an equivalent of asMethodConstant AST manipulation at runtime strategy in the image for this case right now but it's probably a couple lines of code with Reflectivity.
On Sat, May 26, 2018 at 7:28 AM, Clément Bera <bera.clement@gmail.com> wrote:
On Fri, May 25, 2018 at 10:44 PM, Esteban Lorenzano <estebanlm@gmail.com> wrote:
On 25 May 2018, at 17:30, Clément Bera <bera.clement@gmail.com> wrote:
What about a preprocessor like the Java preprocessors ? The Truffle project relies heavily on that for high performance Java and it's quite nice. It's difficult to do that in Smalltalk right now.
I think if you want to do what are asking for you just need to write a bytecode compiler extension.
I did something similar in the past to have precomputed constants through AST manipulation at compilation time. You can find it here with examples: http://smalltalkhub.com/#!/~ClementBera/NeoCompiler. Once the code is loaded you need to recompile the examples (NeoCompilerExample withAllSubclassesDo: #compileAll.). With it you can write code such as: [ Smalltalk vm class ] Cvalue And depending if the compiler allowsPrecompilation or not, the bytecode compiler generates: Smalltalk vm class Or just a push literal with the precomputed value (the class VirtualMachine).
this is not what #asMethodConstant provides?
Can you turn asMethodConstant On and Off so you have the constant in production and not a development time ? Typically at development time I change the constants generated a lot and I don't want to waste time recompiling all the time.
But yeah, my project is from 2014. I guess instead of preprocessing you could do everything at runtime with AST manipulation/recompilation like in asMethodConstant.
The main point of preprocessing IMO is to control performance, it's just easier for me to just look at the generated bytecode and change the preprocessor until it gets what I want, it's not always easy to run code that will change your method at runtime quickly so you can look at the bytecode generated.
Anyway, I am not convinced at all something like that should be in the base image.
Esteban
In the end I decided not to use this, but you can use it and extend it to support more than just constants (any AST manipulation is possible). Just checked it works in Pharo 6.
On Fri, May 25, 2018 at 4:26 PM, Stephan Eggermont <stephan@stack.nl> wrote: Debiller 777 <ozovozovozo202@gmail.com> wrote:
Well, I've already asked about adding new literals to pharo or Smalltalk in general, however this time I have a better idea: macros. Can they be added? Because if I understand correctly they may be the only way to do that.
Why do you think they would be a good idea? We have powerful meta-programming facilities that are well understood and somewhat supported by tooling. How do we get value out of macros?
Stephan
-- Clément Béra https://clementbera.github.io/ https://clementbera.wordpress.com/
-- Clément Béra https://clementbera.github.io/ https://clementbera.wordpress.com/
-- Clément Béra https://clementbera.github.io/ https://clementbera.wordpress.com/