[squeak-dev] Re: Boolean over-optimization #ifTrue:/#ifFalse:
siguctua at gmail.com
Thu Mar 6 12:11:44 UTC 2008
On 05/03/2008, Joshua Gargus <schwa at fastmail.us> wrote:
> The #compilerClass method allows you to specify the compiler to be
> used for a class (and its subclasses). So, one approach would be to
> implement a subclass of Compiler (say, "ProxyCompiler") that disables
> optimization of #ifTrue:ifFalse: etc.
> I'm not sure about a clean way to disable optimizations in a subclass
> of Compiler. Here's a moderately horrible way to disable them
> - give Compiler a boolean class variable "DisableSpecialSelectors"
> - hack MethodNode>>noteSpecialSelector: thusly...
> noteSpecialSelector: selectorSymbol
> " special > 0 denotes specially treated messages. "
> DisableSpecialSelectors ifTrue: [special := 0. ^self].
> "Deconvert initial keywords from SQ2K"
> special := #(:Test:Yes: :Test:No: :Test:Yes:No: :Test:No:Yes:
What are these selectors (:Test:Yes: :Test:No: :Test:Yes:No: :Test:No:Yes:)?
And why they need special handling..
And what SQ2K means?
Ohh.. it seems that its easier to write own parser than using default one.
I'd like to add that a Parser/Compiler are focused on compiling
things, not for examining parse tree, which is bad.
Like, for instance, why MethodNode doesn't have accessor to arguments
ivar and forcing me to use #asTranslationMethodOfClass: only for a
single reason - to have a change to look an argument names of parsed
> and: or:
> :Until:do: :While:do: whileFalse whileTrue
> :Repeat:to:do: :Repeat:to:by:do:
> ) indexOf: selectorSymbol.
> special > 0 ifTrue: [^ self].
> special := MacroSelectors indexOf: selectorSymbol.
> Then, you could override #translate:noPattern:ifFail: in
> ProxyCompiler, as follows...
> translate: aStream noPattern: noPattern ifFail: failBlock
> [ DisableSpecialSelectors := true.
> ^super translate: aStream noPattern: noPattern ifFail: failBlock
> ] ensure: [DisableSpecialSelectors := false].
> Finally, implement #compilerClass on the class-side of your Proxy
> class, and answer ProxyCompiler.
> Heh, that was sorta fun!
Igor Stasenko AKA sig.
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