I feel like I have seen this proposal before, but I can’t find it now and I don’t remember the resolution, so sorry if this is repetitive. I think it would be very nice if single word arguments passed to a function after a semi-colon were interpreted as keyword arguments where the variable name is …

This is implemented in the language itself, since v1.5: add implicit named tuple and keyword argument names JuliaLang:master ← JuliaLang:jb/implicitkwnames opened 10:55PM - 09 Jan 20 UTC (UTC) …

[image] ExpandingMan: The point is that only the value of x matters in this case. You could have called it absolutely anything and it would not matter. Take any piece of code without macros, and transform it by mapping all symbols to new symbols, and it still works. I guess it depends on how …

One thing why not to do so is potential WTFs with macros. Say: f(; kw) = kw kw = 2 f(; kw) # supposedly works @some_macro let kw = 42 f(; kw) # error due to name mangling by the macro end If you want that behavior in your code and can get it with a macro, that’s perfectly fine and is a julia…

I didn’t fully understand the conversation, but have you seen this https://github.com/mauro3/Parameters.jl/blob/master/README.md , it might be a relevant package.

One could get around that by doing the expansion of f(; kw) to f(; kw=kw) before doing macro expansion. Then the macro would rewrite it to f(; kw=var”##3#kw”) or something.

I really like this idea, and I would probably use it a lot if it got implemented. I’ll even go as far as saying that with this feature I’d use keyword arguments a lot more than I do now.

Relevant issue: https://github.com/JuliaLang/julia/issues/29333 . The syntax would also naturally extend to named tuples so that (; a, b) would be syntax for (a = a, b = b).

This can be implemented in a package: using MacroTools: @capture, splitarg macro pun(ex) ret = if @capture ex (f_(args__; kw__)) kw = map(kw) do kwarg key, typ, splat, val = splitarg(kwarg) if splat kwarg elseif val == nothing …

This macro actually works great with no extra cost (which my previous did have). Thanks! I’ll be using this until the feature is added, or forever if its not

I think I would like to put this macro into a package. I just can’t come up with a good package+macro name.

Keyword arguments without a keyword?

Internals & Design

dstarerstor December 10, 2019, 1:41pm 14

I would call it KeywordTools or KwargTools or something like that. I personally like to call the macro @pkw standing for pass-keyword. Maybe @passkwarg.

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Keyword arguments without a keyword?

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