Ah, let’s call it :last then and it points to the segment. There is always one too, so it is always available.
On Fri, Jun 4, 2021 at 22:34 i Dorgan <[email protected]> wrote: > > I think for the dot we don't need end_of_expression, we just update the > outer meta to include the outer identifier. > Sounds good to me > > > For aliases, I guess we can reuse closing? Or maybe last_dot? > Closing points to the location of the closing pair, which implies there is > something wrapped in {}, () or [](or end in the case of anonymous > functions), which is why I was leaning towards end_of_expression. The only > issue I see with end_of_expression is that we need to calculate the length > of the segment(because end_of_expression always point at the very end of > the expression, not just where the last token starts). > > The problem with last_dot is that the last segment may or may not be in > the same line as the dot, for example: > > Foo. > Bar > > or > > Foo > . > > Bar > > Both of which evaluate to the same ast. So the name should refer to the > last segment(:Bar in this case). Maybe last_segment? The syntax reference > docs mention "each segment separated by dot as an argument", so it would be > consistent with that description. > > > And what happens when the alias has no dot? We don't set it? > If the alias has no dot I think we could safely skip the new field, > especially if we go for last_segment since there is only one segment. > El viernes, 4 de junio de 2021 a las 17:10:56 UTC-3, José Valim escribió: > >> I think for the dot we don't need end_of_expression, we just update the >> outer meta to include the outer identifier. >> >> For aliases, I guess we can reuse closing? Or maybe last_dot? And what >> happens when the alias has no dot? We don't set it? >> >> On Fri, Jun 4, 2021 at 10:02 PM i Dorgan <[email protected]> wrote: >> >>> > The dot one is easy, I think we can have the outer meta be the meta of >>> the call identifier. A PR is welcome. >>> Great! I will prepare a PR soon >>> >>> > One alternative is to have something similar to [end: ...] that we >>> have for constructs like do-blocks, so we can at least say where the whole >>> alias extends to? WDYT? >>> Sounds reasonable to me. It would also be way less noisy. >>> I think what's most valuable is to be able to tell the boundaries of a >>> node, not so much what happens in between. >>> >>> Regarding the naming of the fields, do you think end_of_expression would >>> be fine for both? It is described as "denotes when the end of expression >>> effectively happens", which is what we would be adding here. Moreover, they >>> would be the same positions that are already added in such field if the >>> expression is part of a block. >>> El viernes, 4 de junio de 2021 a las 16:13:11 UTC-3, José Valim escribió: >>> >>>> The dot one is easy, I think we can have the outer meta be the meta of >>>> the call identifier. A PR is welcome. >>>> >>>> For aliases, it is trickier, as you said. One alternative is to have >>>> something similar to [end: ...] that we have for constructs like do-blocks, >>>> so we can at least say where the whole alias extends to? WDYT? >>>> >>>> On Fri, Jun 4, 2021 at 6:00 PM i Dorgan <[email protected]> wrote: >>>> >>>>> Hi all, >>>>> >>>>> I'm writing a function that takes a quoted expression and calculates >>>>> the start and end positions of the node in the source code. So for example >>>>> for this expression: >>>>> >>>>> :"foo#{ >>>>> 2 >>>>> }bar" >>>>> >>>>> It would tell us that it starts at line: 1, column: 1 and ends at line: >>>>> 3, column: 6. The idea is that by knowing the boundaries of a node, a >>>>> refactoring tool can say things like "replace the code between these >>>>> positions with this other code". >>>>> >>>>> The issue I'm facing is that there are two cases where the AST does >>>>> not contain enough information to calculate those positions, the first one >>>>> is qualified identifiers: >>>>> >>>>> foo >>>>> . >>>>> bar >>>>> >>>>> which produces the ast: >>>>> >>>>> {{:., [line: 2, column: 1], >>>>> [ >>>>> {:foo, [line: 1, column: 1], nil}, >>>>> :bar >>>>> ]}, >>>>> [no_parens: true, line: 2, column: 1], []} >>>>> >>>>> Note that we don't have any information about the location of :bar, >>>>> only for the dot. This makes it impossible to accurately calculate the >>>>> ending location for the expression, and we are forced to assume :bar >>>>> is at the same line as the dot. >>>>> >>>>> The second case happens with aliases: >>>>> >>>>> Foo. >>>>> Bar >>>>> .Baz >>>>> >>>>> produces: >>>>> >>>>> {:__aliases__, [line: 1, column: 1], [:Foo, :Bar, :Baz]} >>>>> >>>>> Here we have even less information, we know nothing about dots or >>>>> segments location, and we are forced to assume everything happens at the >>>>> same line. >>>>> >>>>> I looked into the parser and this information is being discarded in >>>>> the build_dot function for qualified identifiers and in >>>>> build_dot_alias for aliases. >>>>> >>>>> My proposal is to keep that information in the ast metadata instead of >>>>> discarding it when the :token_metadata option is true, similarly to >>>>> how it is done with do/end, closing and end_of_expression. >>>>> >>>>> The quoted form of the first example would be something like this: >>>>> >>>>> {{:., >>>>> [ >>>>> identifier_location: [line: 3, column: 1], >>>>> line: 2, >>>>> column: 1 >>>>> ], >>>>> [ >>>>> {:foo, [line: 1, column: 1], nil}, >>>>> :bar >>>>> ]}, >>>>> [no_parens: true, line: 2, column: 1], []} >>>>> >>>>> For the aliases it would be a bit more involved, because there are two >>>>> kind of locations that would need to be preserved: dots and segments. I've >>>>> considered something like this to keep only the segments: >>>>> >>>>> {:__aliases__, >>>>> [ >>>>> line: 1, >>>>> column: 1, >>>>> alias_segments: [ >>>>> [token: :Foo, line: 1, column: 1], >>>>> [token: :Bar, line: 2, column: 1], >>>>> [token: :Baz, line: 4, column: 1] >>>>> ] >>>>> ], [:Foo, :Bar, :Baz]} >>>>> >>>>> I already have a working version, so I will gladly submit a PR if you >>>>> consider this to be viable. I'm still unsure on how to tackle the dots >>>>> positions in a meaningful way. While just knowing the segments positions >>>>> is >>>>> enough for my use cases, I figure dot positions may also need to be >>>>> preserved for the sake of completeness. >>>>> >>>>> I'd like to know your thoughts! >>>>> >>>>> -- >>>>> 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/815d3113-dae6-4e99-8427-a873a704c4aan%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/elixir-lang-core/815d3113-dae6-4e99-8427-a873a704c4aan%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>> >>>> >>>>> -- >>> 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/ffd16955-f791-40b8-bd40-1cf37322995an%40googlegroups.com >>> <https://groups.google.com/d/msgid/elixir-lang-core/ffd16955-f791-40b8-bd40-1cf37322995an%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > 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/ca7b5fe2-b767-40fe-899f-ab915989f2c4n%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/ca7b5fe2-b767-40fe-899f-ab915989f2c4n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. 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