In the first place why I'm doing this. I work on Rewrite Tool and it's main functionality bases on replacing nodes in AST. Plus it works with sourceIntervals of nodes. Untill now my solution was: if I replace node, I reparse tree to get intervals updated However this solution brought new problems. Second reason is, that I think it makes sense to update interval of all AST if you replace one node. For example, we have: obj1 foo + obj2 bar and we replace obj1 with myObject. The interval of ast was 1 to: 19, and now it should be 1 to: 23.
Mark 2014-10-28 14:00 GMT+02:00 Thierry Goubier <thierry.goub...@gmail.com>: > Le 28/10/2014 12:45, Mark Rizun a écrit : > >> Yes, because they are wrong. Here is an issue: >> https://pharo.fogbugz.com/f/cases/14254/AST-method- >> replaceWith-does-not-change-source-interval >> > > I would say that they are correct. > > When I write source to source compilers, I admit that anything that I > change in the AST (via replaceWith equivalent) has no valid source interval > (since it does not exist in the original source). However, all unmodified > nodes should keep their 'non-modified' source interval (since I may need it > to fetch the relevant text from the source). > > If I want my modification to the AST to have valid source intervals, then, > I need to regenerate the source from the modified AST. And only then they > are valid. > > You may want to update the source interval when you do a replaceWith, but > the only thing we will get with what you want to do is that, after a > replaceWith, no source interval can be trusted since it may end up past the > end of the original source string length. > > Thierry > > >> 2014-10-28 13:32 GMT+02:00 Thierry Goubier <thierry.goub...@gmail.com >> <mailto:thierry.goub...@gmail.com>>: >> >> >> Le 28/10/2014 12:12, Mark Rizun a écrit : >> >> Well, not really. >> >> Technically, tokens are used to drive a parser from a >> scanner. >> >> If an AST node knows how to relate itself to its original >> source >> code chunk and is able to print itself correctly, then >> tokens are >> redundant. >> >> In short, if you work with parsers, you'd better know what >> tokens >> are. If you're only working with the AST, tokens are >> redundant and >> noise (i.e. they often have a type (or more than one) which >> is only >> understood by the parser). >> >> >> I'm working with ASTs sourceInterval. Trying to calculate it after >> method replaceWith:. >> You see, my proble was that each node of AST doesn't hold its >> start and >> stop position in same place. So I thought that token is such a >> place, >> however, eventually I understood that RBValueNodes don't have >> tokens:) >> >> >> Do you mean you're trying to do a replace and update the positions >> of all the nodes ? >> >> Thierry >> >> >> > >
