Arjan, So sounds like we both ran in to the same issue of refactoring/code manipulation with the problem of losing comments. -Steve
On Tue, Apr 23, 2019 at 11:48 AM Arjan Scherpenisse <[email protected]> wrote: > Yes, sorry, a part of my talk at Elixirconf was about using the AST as the > source for "intelligent" refactoring tools; renaming functions, inlining > variables, extracting functions, etc. > It should be online soon, I think, slides are here > <https://docs.google.com/presentation/d/15_xKuL_H4Eu-EkGarxVixCk192858avE1ef1gmcVKoc/edit?usp=sharing> > . > > Arjan > > On Tuesday, April 23, 2019 at 6:29:20 PM UTC+2, Steve Morin wrote: >> >> Arjan Scherpenisse >> What is you're use-case? >> >> On Tue, Apr 23, 2019 at 4:20 AM Arjan Scherpenisse <[email protected]> >> wrote: >> >>> I actually discussed a solution like this with José in Prague but this >>> will also become complicated very quickly, especially as these primivite >>> nodes can be nested (e.g. keyword lists and normal lists). Maintaining the >>> correct position in the parent is also problematic when you want to do >>> something with the child nodes, for instance if you write an AST transform >>> to swap 2 parameters of a function call, the comments would not get swapped. >>> >>> For the short term I've put this subject to rest. My opinion is that for >>> tooling that depends on code -> ast -> code transforms, we need more >>> specialized tooling. For instance, we cannot assume that the input source >>> code is already properly formatted; Ideally a source code modification tool >>> should work with all kinds of source code, and a transformation should only >>> affect the local scope, and not, for instance, reformat all of the output. >>> I could even imagine it working with code that is not syntactically >>> correct. That is a subject that the Elixir parser was just not meant to do, >>> and trying to squeeze comments into the AST would not solve this. >>> >>> I have been looking at the Wrangler >>> <https://github.com/RefactoringTools/Wrangler/> source code, which is a >>> set of Erlang refactoring tools, but I have not come very far yet. It is an >>> interesting source of information though. >>> >>> Arjan >>> >>> On Tuesday, April 23, 2019 at 12:18:07 PM UTC+2, [email protected] wrote: >>>> >>>> What about "hoisting" the comments into the metadata of the surrounding >>>> block for the primitive AST nodes? >>>> This means that we need to be able to specify *where* in a >>>> `:__block__` a comment ought to occur, which shouldn't be a problem: The >>>> only cases where this information will be out of date is when macro >>>> rewriting alters the AST, which is a situation that would probably remove >>>> the comments anyway. >>>> (so e.g. a formatter would need to move comments with the code just as >>>> is the case currently, but optimization tools would not care about comments >>>> anyway). >>>> >>>> This 'where' might take the format of a keyword-list, with >>>> half-line-numbers as keys and strings (containing the actual comments) as >>>> values. 'half-line-numbers ' go from 0 up to and including >>>> `2*n_lines_in_block`. Even numbers are comments occuring before (e.g. on >>>> the line above) `div(half-line-number, 2)`. Odd numbers are comments >>>> occuring after (at the end of the same line as) `div(half-line-number/2)`. >>>> >>>> >>>> So >>>> >>>> quote do >>>> # one is the lonliest number >>>> 1 >>>> 2 # two is the smallest prime >>>> 3 >>>> # I am at the end >>>> end >>>> >>>> >>>> >>>> would compile to >>>> {:__block__, [comments: [0 => "one is the lonliest number", 3 => >>>> "two is the smallest prime", 6 => "I am at the end"]], [1,2,3]} >>>> >>>> >>>> ~Marten / Qqwy >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "elixir-lang-core" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/elixir-lang-core/df0438ce-45cb-4c90-b87c-c7a1ee9cc41b%40googlegroups.com >>> <https://groups.google.com/d/msgid/elixir-lang-core/df0438ce-45cb-4c90-b87c-c7a1ee9cc41b%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> -- >> Steve Morin | Hacker, Entrepreneur, Startup Advisor >> twitter.com/SteveMorin | stevemorin.com >> *Live the dream start a startup. Make the world ... a better place.* >> > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/6fa656e1-6eec-4ad9-be50-e0f503edf58a%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/6fa656e1-6eec-4ad9-be50-e0f503edf58a%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- Steve Morin | Hacker, Entrepreneur, Startup Advisor twitter.com/SteveMorin | stevemorin.com *Live the dream start a startup. Make the world ... a better place.* -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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