On Tue, Jul 12, 2011 at 8:51 AM, Lukas Renggli renggli@gmail.com wrote:
I guess you are referring to the extension methods in the package 'PetitAnalyzer'? The methods #matches:, #matchesIn:. #matchingRangesIn:, ... are part of the core package 'PetitParser' and are well commented (I think).
The methods in the package 'PetitAnalyzer' are called match*, because this is not an equality operation. They do not only support the comparison of two parsers, but can also compare patterns with parser instances (essentially this is a little Prolog engine, very similar to the refactoring engine). The matching and rewriting of parsers is explained in my PhD (http://scg.unibe.ch/archive/phd/renggli-phd.pdf) in Section "6.2.5 Declarative Grammar Rewriting".
I will have a look, thank you
- PPParser>>matchList* do never refer to self (but to call themselves
recursively).
This looks correct to me. This is to recurse into the graph of parsers.
Because these methods do not refer to self, they could be implemented in a different class to avoid cluttering the already large PPParser. I think Kent Beck is talking about that in the Best Practice Patterns :-)
- Why is #def: not defined in PPUnresolvedParser? You implemented it
in PPParser. It might be useful for other parsers, but do you have an example?
PPParser is a superclass of PPUnresolvedParser, therefore you can send #def: to any instance of PPUnresolvedParser.
Sure. But why did you put #def: in PPParser and not directly in PPUnresolvedParser? For example, what is the meaning of
#digit asParser star def: #letter asParser
?