[Rd] Parser bug? A comma too much.

[Duncan Murdoch]

On 16/09/2022 10:33 a.m., Rui Barradas wrote:
> Hello,
> 
> Why doesn't the comma throw an error?
> 
> 
> plot(1:5,)    # works, no complaints

That says the second argument is missing.

You need this to enter missing arguments with positional matching, e.g.

f(a, , b)

sets the second argument of f() to missing, but the third is set to b.

Duncan Murdoch

> 
> 
> Shouldn't this be considered a bug? I would expect the parser to at
> least give a warning.
> 
> 
> sessionInfo()
> R version 4.2.1 (2022-06-23 ucrt)
> Platform: x86_64-w64-mingw32/x64 (64-bit)
> Running under: Windows 10 x64 (build 22000)
> 
> Matrix products: default
> 
> locale:
> [1] LC_COLLATE=Portuguese_Portugal.utf8
> LC_CTYPE=Portuguese_Portugal.utf8
> [3] LC_MONETARY=Portuguese_Portugal.utf8 LC_NUMERIC=C
> 
> [5] LC_TIME=Portuguese_Portugal.utf8
> 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> 
> loaded via a namespace (and not attached):
> [1] compiler_4.2.1
> 
> 
> Rui Barradas
> 
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