Can we get compile time routines?

Something like

$data = compile_time_routine(function() {
    return json_decode(file_get_contents("large.json"), true);
});

being equivalent at runtime to

$data = array(...whatever json_decode returned...);

and

echo "opcache compiled at " . compile_time_routine(function(){return
date(DateTime::RFC3339);});

being equivalent at runtime to

echo "opcache compiled at " . "2023-03-16T09:43:00+01:00";

• at my work there are jsons which is being fetched/parsed like

$data=json_decode(file_get_contents("large.json"), true);

several times per second, while it would be fine for them to only be
fetched/parsed every time opcache is reset.

You can already sort of do this by having a build script that reads the JSON file and then uses var_export() to dump it to a file. You can then just require the file to get the resulting array.

Not precisely the same, but gets the same benefit in this case.

--Larry Garfield