WESL: The extended WGSL language, and is pronounced like “weasel”. Stands for WebGPU Enhanced Shading Language.
WESL linker: A program that implements the WESL specification and transpiles WESL source code to WGSL.
Part of the process of translating WESL involves linking together multiple WGSL and WESL modules.
Also akin to bundler in the JavaScript/TypeScript world.
Mangling: link process in which certain declarations are renamed to avoid name conflicts.
Side effects: WESL/WGSL shader code that is visible to host code (e.g. in Rust or JavaScript).
Changes to that shader code have the side effect of changing the host interface to the shader.
Directives: Generated WGSL code must agree on a set of directives
(Maybe const_assert?)
Visibility: An item’s visibility defines which modules can reference or re-export it.
Visibility has three levels: public, package (the default), or private.
For a pipeline-relevant item, visibility also controls whether the main module exposes it to the host. See Visibility.
Module: A unit of WESL or WGSL code with its own top-level scope, stored in a single module source.
Module Source: The stored text of a module, typically in a WESL or WGSL file.
Main module: The WESL module from which translation starts. It defines the Pipeline-visible API. A single application can have many main modules.
Pipeline-visible API: The set of items which are visible to the host (CPU-side). Pipeline-visible item names are not mangled.
Path: A ::-separated path written in an import statement or inline import. It may start with super:: segments. In import statements, it may be suffixed with an import collection ({}), which flattens into separate imports paths.
Canonical Path: The unique fully qualified import path naming a module or declaration. It does not contain super::. import paths can be canonicalized.
Module Path: A canonical path naming a module; equivalently, a declaration path minus its final segment.
Declaration Path: A canonical path whose final segment names a declared item.
Importable item: Items that can be imported by other modules.
Package: A publishable body of WESL code containing multiple files. Akin to a JavaScript npm package or a Rust crate.
wesl.toml: The optional configuration file for a package. See WeslToml.
Module Path Resolution: Mapping between module paths and module source within a package. Choice of mapping is specific to the storage type (filesystem, in-memory source, URL-based, etc.).
Filesystem Resolution: The standard path resolution for a filesystem storage. It maps module paths to file paths relative to a Package Root Directory. See Filesystem Resolution.
Package Root Module Path: The module path consisting only of package. With the filesystem resolution, it is mapped to an optional package.wesl file in the package root directory.
