[Perl 6]: Small discoveries VII, Flattening

Perl 6 tries to flatten lists. This:

my $a = [[["hello"]]]; #not a 3d array!, same as: ["hello"]
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is not what you might think it is, as single element lists get flattened. To get what you mean you must write

my $a = [[["hello"],],]; #now it is!
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Note the trailing comma. See also 2015 The Year of The Great List Refactor.

holli

You can lead your users to water, but alas, you cannot drown them.

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Re: [Perl 6]: Small discoveries VII, Flattening by QM (Parson) on Oct 31, 2017 at 10:15 UTC
Note the trailing comma. Which is horribly like some Python I've had to write. I hate it when syntax DWIMs the wrong way. `> python >>> x = (1) >>> x 1 >>> x = (1,) >>> x (1,)` [download] So `(1)` is not a tuple, but `(1,)` is? Back to Perl... Does the number of trailing commas affect anything? E.g., `[[["hello"],,,,],,,,]`. (Because in Python it's a syntax error!) -QM -- Quantum Mechanics: The dreams stuff is made of	[reply] [d/l] [select]
Re^2: [Perl 6]: Small discoveries VII, Flattening by Anonymous Monk on Oct 31, 2017 at 14:22 UTC
So `(1)` is not a tuple, but `(1,)` is? `(1)` is a parenthesized expression, not a tuple. Same with `(1+1)`. This is an unfortunate result of having two different meanings for parens. Does the number of trailing commas affect anything? Consecutive commas are also a syntax error in Perl6.	[reply]
Re^3: [Perl 6]: Small discoveries VII, Flattening by Anonymous Monk on Oct 31, 2017 at 16:51 UTC
Parens don't build lists in Perl6, commas do: `my @a := 1,2; say @a.^name; #List my @b := 1,; say @b.^name; #List` [download] Parens are usually needed because of precedence when embedding the List into another expression. The comma does have another meaning: it's the separator in argument lists.	[reply] [d/l]
Re^4: [Perl 6]: Small discoveries VII, Flattening by Anonymous Monk on Oct 31, 2017 at 17:08 UTC
Re: [Perl 6]: Small discoveries VII, Flattening by Anonymous Monk on Oct 30, 2017 at 15:24 UTC
... Why? Is it just for symmetry with `List` constructor `(42,)`?	[reply]
Re: [Perl 6]: Small discoveries VII, Flattening by Jenda (Abbot) on Dec 29, 2017 at 21:58 UTC
As if we needed more reasons to ignore the misnamed misdesigned language. Jenda Enoch was right! Enjoy the last years of Rome.	[reply]