> On Jan 5, 2020, at 5:04 PM, tyson andre <[email protected]> wrote:
>
> I have a work in progress wrapper for allowing const-like syntax for global
> constants `static const X = $dynamicExpression;`.
> This can be seen in https://github.com/TysonAndre/php-src/pull/10
Thanks for replying and including this. Nice work.
> - Eagerly initialized dynamic constants are easier to reason about in some
> ways (e.g. fetching the constant of an already fetched class is less likely
> to cause pauses or exceptions.)
> This makes un-noticed errors in rare code paths less likely.
> - Attempting to support function calls, property accesses, class constant
> accesses (e.g. inherited), and variables in class constants recursively
> and/or lazily
> would probably break a lot of code/assumptions in the php engine.
Frankly my strong preference would be for on-demand initialization because
otherwise each page load could end up running lots of code to calculate values
that are never used on the particular page.
> My preference would be to make it easier to use dynamic expressions, and
> recommend in coding guidelines that
> certain types of expressions "SHOULD NOT" be used for constants that vary on
> a particular host.
> (network calls, time, etc)
>
> ```
> const DEFAULT_PAYLOAD = json_encode(['key' => 'value']);
> const ALLOWED_ELEMENT_TYPES = array_merge(self::FIRST_TYPES,
> self::SECOND_TYPES);
> const ELEMENT_LENGTHS = array_map('strlen', self::ELEMENTS);
> ```
You and me both.
-Mike
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