Re: Empty element elision and associative arrays (was Re: Slurping a file)

["Mark J. Reed" <markjreed@gmail.com>]

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On Mon, Jan 15, 2024 at 2:02 AM Lawrence Velázquez <larryv@zsh.org> wrote:

> There is no "inevitable" teration order; one must be usually be chosen and
> implemented
> explicitly, which is extra complexity that many languages choose not to
> bother with.


Indeed. To be clear, several do choose to bother; examples include Python
since 3.6, Ruby since 1.9, and PHP, which all maintain their associative
data types in insertion order. (That introduces potential pitfalls in PHP,
where *all* arrays are associative; regular ones just have numeric keys,
but those can still be rearranged out of numerical order! JavaScript avoids
that pitfall by using numeric order for numeric keys while maintaining
insertion order for non-numeric ones.)

Closer to home, the KornShell keeps its associative arrays in lexical order
by key. Which is to say there is precedent for keeping things in a
specified order, but Zsh doesn't do so. Even if it were changed such that
it started to do so as of 6.0 or whatever, you'd still have to write code
to check the version and either fail ungracefully or fall back to
maintaining the order in a separate array anyway. So even in that world,
it's simpler to just do the separate ordering in the first place, yielding
code that works in any version – at least, any version with associative
arrays.

-- 
Mark J. Reed <markjreed@gmail.com>

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