Built-in Modules · Issue #395 · tc39/ecma262 (original) (raw)

Built-in modules come up repeatedly around the various proposals. I am making this issue to centralize the discussion such that champions of the eventual proposal have a good central location for information. I will keep this up-to-date if there is further discussion in this issue.

Existing Discussion

• Can this API be provided as a standard module rather than globals? ecmascript_simd#323

Syntax Options

Naming convention inside module specifier

This option entails establishing a naming convention for built-in modules. Has to be compatible with existing ecosystems, eg. we cannot clobber an npm or standard node package name.

Strawman: *-sigil

import "*SIMD";
import {float32x4} from "*SIMD";
import SIMD from "*SIMD";

Strawman: URL scheme

import { float32x4 } SIMD from "std:SIMD";

Distinct syntax for built-in module imports

This option necessitates additional reflective capabilities in the Loader API to request built-in modules by name as opposed to going through the normal module resolution process.

Strawman: IdentifierName instead of StringLiteral

import SIMD;
import {float32x4} from SIMD;
import SIMD from SIMD;

Semantics Requirements

Must defer to loader to resolve built-in modules (important for polyfillability). Loader may see either a special string or possibly an options record indicating that a built-in module is requested.