Package-level interface

[emil14]

pub interface IKeyValueStore {
    Get<T>(key string) (some T, none any)
    Set<T>(key string, value T) (ok any, err error)
    Delete(key string) (res any, err error)
}

def Foo(sig any) (res any, err error) {
    kv_get IKeyValueStore.Get<int>
    kv_set IKeyValueStore.Set<int>
    kv_del IKeyValueStore.Delete?
    ---
    :sig -> 'foo' -> kv_get
    kv_get:some -> 'bar' -> kv_set
    kv_set:ok -> 'foo' -> kv_del -> :res
}

...

import {
    redis
    runtime
}

def Main(start any) (stop any) {
    foo_redis Foo{redis} // passing a package as a dependency
    panic runtime.Panic
    ---
    :start -> foo_redis
    foo_redis:res -> :stop
    foo_redis:err -> panic
}

Normal interface describes component - input and output ports. Package interface describes package - public components are like methods.