Le 13/09/2015 08:56, Marcus Denker a écrit :
On 12 Sep 2015, at 19:23, Peter Uhnák <[email protected]
<mailto:[email protected]>> wrote:
| rewriter |
rewriter := RBParseTreeRewriter new
replace: ' `#aLiteral `{:node | node value isCharacter}'
with: '`#aLiteral aMessage'; yourself.
rewriter executeTree: (RBParser parseExpression: 'Array with: $a
asciiValue with: $b with: #c with: d').
rewriter tree formattedCode
This is cool! And so simple!
This can be combined with the compiler transform plugins of Opal:
-> make subclass of OCCompilerASTPlugin
-> put your code in a method called #transform
now when you override #compiler on the class side of a class like this:
compiler
^super compiler addPlugin: ASTPluginMeaningOfLife.
the plugin will be active for the hierarchy, which means that all code
compiled will be transformed.
There is a simple example ASTPluginMeaningOfLife in the image.
Cool. Intriguing.
I'm sure I can use it to:
- patch problematic code on the fly without registering an override
- change the semantics of some smalltalk statement (so that a := becomes
self a: or anything else)
Would it be possible to couple it with Clement work to have some ability
to pre-compile some code in specific classes (strength reduction, once
literals) where we know that this is valuable?
It would also be nice to have a way not to write bytecode by hand, like,
say, in the slots example of a few days back.
Oh, ok, for the literal stuff, I think I know how to do it:
In a method:
- replace target expression with symbol literal.
- evaluate target expression in isolation, store value.
- compile method with symbol literal.
- in compiled method, replace symbol literal with value stored above.
Would that work?
Thierry
Marcus
