That's it! There is even a little documentation so you could try to re-use the traversal function separate of the GUI if you want. Let me know if there's something more to improve in this direction.
Robby On Fri, Jun 20, 2014 at 8:10 PM, Jonker, Todd <jon...@amazon.com> wrote: > Thank you for the tips pointing me in the right direction. > > Apologies for not giving more context; that would certainly help. I’ve been > embedded deeply in Racket-space for a couple years now, but lawyers prevent > me from talking about my work and I’ve only recently been given permissions > to ask questions in public. Please forgive my being indirect and opaque when > I’d much rather dish the dirt. > > I have a fairly intimate understanding of the macro expander, and understand > that the resulting syntax objects retain source location, lexical context, > and various properties. Very soon after sending my email it dawned on me > that I’d mistakenly assumed that the editor retained the original source > objects and built a visual model atop that, but now I see that’s not the > case. It looks like the association between the expanded source objects and > the original source text is done solely through the source-location. Fair > enough. > > Since my last mail I discovered drracket/private/syncheck/traversals which > seems to be the meat of it. I see that it recursively parses the expanded > code (core syntax forms), builds several indices and cross-references, then > sends the results to the editor layer via various syncheck-annotations > methods. > > In other words I think I’ve got a handle on it now. > > Thanks again everyone! > > —Todd > > From: Matthias Felleisen <matth...@ccs.neu.edu> > Date: Friday, June 20, 2014 at 5:22 PM > To: "Todd V. Jonker" <jon...@amazon.com> > Cc: "users@racket-lang.org" <users@racket-lang.org> > Subject: Re: [racket] Inner workings of source annotation > > > On Jun 20, 2014, at 5:07 PM, Jonker, Todd wrote: > > Greetings, > > I’m interested in learning how DrRacket’s “Check Syntax” feature works. > > As I understand it, the process is (1) perform full macro-expansion on the > source code; (2) map elements of the expanded code back to the source code; > (3) use that mapping to apply annotations/markup to the source code. The > documentation at http://docs.racket-lang.org/tools/Check_Syntax.html seems > to cover step (3), but I’m struggling to understand how (2) works. > > In other words, I’m trying to learn how the lexical information in the > expanded syntax objects is mapped back to the appropriate parts of the > original syntax objects. I’m reading the code to try to figure out the > algorithm but hoping that there’s a paper that describes it more directly. > > Thanks in advance for any pointers, > > > > > Hi Todd, good to see you on the list. > > (1) local-expand is your friend, (2) the syntax system already propagates > source location information (see syntax/loc in the docs), and (3) if I am > guessing correctly you may want to look at "syntax property" lists in the > docs just in case you want to implement a language of your own that needs to > communicate between layers of expansion. > > The Typed Racket example is the best documented in this regard. And the best > paper to read is > > Languages as Libraries > http://www.ccs.neu.edu/racket/pubs/#pldi11-thacff > > If you play with Typed Racket, you will see that DrRacket 'lifts through' > the syntax. It will do so for any language you create in the #lang spirit > (with 2) and even macros. > > There is also a paper on DrScheme and its implementation, which explains a > bit about other aspects of implementing these things. It's probably much > less helpful > > If this doesn't help, perhaps you can ask more specific questions. -- > Matthias > > ____________________ Racket Users list: http://lists.racket-lang.org/users
