meta-compat

Synopsis

/load meta-compat
/bind <sequence> meta<number>_character
/bind meta<number>-<suffix> <action> [<arguments>]

Description

Older ircII scripts used numbered meta states to describe multi-key bindings. EPIC6 binds arbitrary key sequences directly, so its C binding actions no longer implement those old meta-state commands. meta-compat translates the old notation into ordinary sequence bindings for legacy scripts.

Load it before the old script. It defines a replacement bind alias, records which sequences introduce each meta level, and expands meta<number>-<suffix> for every known prefix of that level. A legacy assignment can be remembered before its prefix is defined; assigning the prefix later replays the stored suffix bindings. It also accepts meta<number> without _character as the prefix action shorthand.

Translation uses encode and decode from builtins, normally supplied by default startup. The resulting action must still be registered with EPIC. This script translates sequence notation; it does not recreate every retired action named by an old configuration.

Default prefixes

On load, the script initializes these compatibility definitions:

These are its EPIC4-1.0.1 compatibility defaults, not a complete statement of your terminal's key sequences. Ordinary sequence characters remain case-sensitive under the built-in binder, while action names and script meta identifiers use the client's usual case-insensitive name handling.

Binding changes and reset

Translated assignments eventually call the C bind command. Non-meta assignments and queries are normally forwarded too. Replacing a sequence that previously introduced a meta level removes tracked dependent bindings for that prefix. Binding a legacy suffix to nothing removes its stored action and unbinds the translated sequences.

/bind -defaults is specially intercepted: it runs the C binding reset, clears compatibility metadata, and reinstalls the prefix definitions above. That C reset also discards custom registered binding actions. Merely loading or rerunning metacompat.defaults resets compatibility metadata without performing that full C reset; existing translated bindings are not comprehensively undone.

Use //bind to bypass this alias for a direct built-in operation. Such changes are not tracked by the compatibility layer and can leave its metadata inconsistent with the actual bindings. Legacy meta queries are not a complete read-only emulation either: the meta branch writes its remembered action from the supplied action text, so querying without an action can clear that remembered definition. Prefer direct built-in inspection of the actual expanded sequence.

Limitations

The sticky behavior of historical META4 is not supported; it behaves like an ordinary meta level. Recursive or cyclic prefix definitions can trigger meta-compat: recursed too many times for /bind ... after its depth counter exceeds 100. That early return does not unwind the counter normally, so a bad definition can interfere with later translations rather than being a clean rejected transaction.

Loading or resetting the layer changes binding behavior and metadata immediately. It has no script-specific settings, persistence file, IRC requests, or function return value. Other scripts can replace its bind alias; it is not an independent parser installed inside the C binder.

For new configuration, write explicit key sequences rather than adding meta states. For example, an Escape-x binding can be written directly as /bind ^[x forward_word without this translator.

Example

/load meta-compat
/bind ^[ meta1_character
/bind meta1-x forward_word

This associates Escape with meta level 1 and binds Escape followed by lowercase x to forward_word. It changes local input behavior only.

History

Written by Ben Winslow (|Rain|); first included in EPIC4-1.2.5. Arbitrary sequence binding had already replaced the need for manual meta-state control in EPIC4pre2.001.

Source references

• script/meta-compat: replacement alias, remembered prefixes/suffixes, defaults, and recursion guard.
• source/keys.c: direct sequence parsing, action validation, nothing, and default reset.
• script/builtins: encoding/decoding wrappers used for metadata keys.