Module host_bindings 

ECS-safe host bindings for Fusabi plugins

This module provides host bindings that allow Fusabi-powered plugins to interact with Scarab’s ECS (Bevy) architecture without direct World access. All interactions go through message passing and the plugin host system.

Architecture

Plugins communicate via PluginAction events which are processed by the client’s plugin host system. This provides:

• Safety: No direct ECS/World mutation from plugin code
• Sandboxing: Per-plugin capability flags and quotas
• Rate limiting: Protection against runaway plugins

Example (Fusabi Script)

module MyPlugin

open Scarab.Host

[<OnLoad>]
let onLoad (ctx: PluginContext) =
    // Register a focusable region
    Host.registerFocusable ctx {
        X = 10us
        Y = 5us
        Width = 20us
        Height = 1us
        Label = "Click me"
        Action = OpenUrl "https://example.com"
    }

    // Enter hint mode
    Host.enterHintMode ctx

Safety Constraints

All host bindings enforce safety constraints:

Constraint	Default	Description
max_focusables	50	Max focusables per plugin
max_overlays	10	Max overlays per plugin
max_status_items	5	Max status bar items per plugin
rate_limit	10/sec	Actions per second
bounds_check	enabled	Coordinate validation

See HostBindingLimits for configuration.

Structs

HostBindingLimits

Configuration limits for host bindings

HostBindings

ECS-safe host bindings for Fusabi plugins

PluginRateLimiter

Rate limiter state for a single plugin

ResourceCounter

Resource counter for tracking plugin resource usage

ResourceUsage

Current resource usage snapshot

Enums

NavKeymap

Navigation keymap configuration

NavStyle

Navigation style configuration

Constants

DEFAULT_MAX_FOCUSABLES

Default maximum focusables per plugin

DEFAULT_MAX_OVERLAYS

Default maximum overlays per plugin

DEFAULT_MAX_STATUS_ITEMS

Default maximum status items per plugin

DEFAULT_RATE_LIMIT

Default rate limit (actions per second)