This section describes the conventions used here to describe type signatures.
A [T] is an array-like value (only ever used read-only in this API), i.e., one with an integer length and whose indexed properties from 0 to length - 1 are of type T.
A type T? should be read as T | undefined -- that is, an optional value that may be undefined.
A realm object abstracts the notion of a distinct global environment.
Extensible web: This is the dynamic equivalent of a same-origin <iframe> without DOM.
r = new Realm(options); // {
// indirectEval: ((...any) -> string)?,
// directEval: {
// translate: ((...any) -> string)?,
// fallback: ((any, any, ...any) -> any)?
//. }?,
// init: ((object) -> void)?
// }?Every component of the constructor argument is optional (meaning that it can be undefined and will be provided with a default behavior).
The indirectEval hook allows custom evaluation behavior for indirect calls to the eval function.
The directEval hooks allow custom evaluation behavior for direct calls to the eval function. The translate hook is used when a true direct eval is performed, that is, when a call to an apparent direct eval turns out to be calling the true eval function. The fallback hook is used when an apparent direct eval turns out to be calling something other than the true eval function. The first argument passed to the fallback hook is the this binding, the second argument is the callee, and the remaining arguments are the arguments that were passed to the call.
The init callback is passed an object containing the standard ECMAScript builtins for the realm. A host environment may also provide additional builtins specific to the host environment. (For example, the browser would provide atob and btoa and other standard browser globals that are not tied to the DOM.) The this binding of the initializer function is provided as the new realm object. This can be used to initialize the realm, for example:
var realm = new Realm({
init: function(builtins) {
extend(this.global, builtins);
}
});If the init callback is provided, the global object is initialized to an empty object with a null [[Prototype]]. If it is not provided, the global object defaults to containing the complete set of normal builtins, with their standard attributes as specified in the standard library, and with the realm's Object.prototype intrinsic as the [[Prototype]].
The global object associated with the realm.
Synchronously execute a top-level script.
Extensible web: This is the dynamic equivalent of a <script> in HTML.
// eval : (string) -> any
v = r.eval(src)This section describes how the Loader class is extended to integrate with custom realms.
l = new Loader({
realm, // Realm?
...
}) // : Loader<ModuleAddress, ModuleSource>Returns the realm associated with the loader.
Convenience: returns the global associated with the loader's realm.
Is this proposal alive?