Extendable format specifiers about pawnplus HOT 2 CLOSED

Coincidentally, I was thinking about this yesterday. The goal is to first separate the current format specifiers used by str_format and make them handled by a corresponding tag function for every tag, then link the specifiers back to the tags (with multiple specifiers linking to a single tag, like d and x) and allow other specifiers to be added. tag_op_string would be changed to tag_op_format and would receive the additional format parameters, if any (as a string).

The basis for this was already outlined in 5104426, but a lot of work still needs to be done.

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@AGraber
Implemented in 12cd765 and newer commits.

A specifier like %d is now decomposed into two actions: find the tag that corresponds to the selector (cell) and let that tag handle the format.

The first part is configurable via str_register_format which allows modifying the internal table and changing what the letters correspond to, or adding new ones.

The actual format operation is handled by tag_op_format (and tag_op_string as a fallback). The signature of the handler is as follows:

forward String:handler(value, type, String:format);

Due to the limitations of the inner workings (and also the fact that tag operations can be also assigned from the underutilized C API and now also to expressions), only a single cell value can be passed to the handler. However, with the is_string parameter of str_register_format, a string can be automatically converted to String:.

What remains are two "unconfigurable" cases: the %P specifier which depends on the AMX instance and thus cannot be handled by any tag, and the sole case of a single "%s" format string which is optimized to skip this whole tag lookup due to its frequent use. However, both of these and also non-letters are allowed in str_register_format.

The format operation can be also called manually (expecting the same layout of arguments as the handler) or from str_val.

It's funny that this took me two years of waiting and two days of actual programming.

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