Using WIT resources

This section contains language-specific guides on how to use WIT resources.

Resources represent functionality that is implemented only on one side of a component boundary, for example in another component or in the underlying platform/host.

An example of a resource:

package docs:calc-resource@0.1.0;

interface types {
    enum operation {
        add,
        sub,
        mul,
        div,
    }

    variant execute-error {
        divide-by-zero,
        unexpected(string),
    }

    resource stack-calculator {
        constructor();
        push-operand: func(operand: u32);
        push-operation: func(operation: operation);
        execute: func() -> result<u32, error>;
    }
}

world calculator {
    export types;
}

Hosts or Components implementing the stack-based calculator above do share the resource (the stack-calculator entity) with components that import that functionality, but do not share the actual implementation. All calls to stack-calculator resources resolve inside the component that exported the functionality.

Languages

This guide is implemented for various languages: