@hydranium/langium

The pinned Langium re-export for the Hydranium framework — the single chokepoint every @hydranium/* package, and every adopter of them, imports Langium through.

You do not install this for its own API: it is almost entirely passthrough. You install it because a framework package will resolve it anyway, and because importing Langium through it is how your project stays in lockstep with the version the framework was built against.

Why this package exists

Langium is pinned to one exact version here, to guarantee a single physical copy across the workspace. Re-export is transparent — given one physical install, importing AstNode or URI from @hydranium/langium and from langium yields the same class object and the same declaration. That transparency is exactly what a split install destroys: two copies of Langium mean two AstNode declarations and two URI classes, so instanceof and every nominal identity check across them silently start returning false. Without the pin, single-copy is only a semver-dedup coincidence, one minor bump away from breaking.

For an adopter, the reason to route imports here is not runtime identity (that already holds) — it is version coupling. Langium sits in an atomic chain with vscode-languageserver, vscode-languageserver-protocol and vscode-jsonrpc, with no independently movable link. An adopter importing langium directly owns that pin itself and can drift out of lockstep with the framework it composes; importing it from here means the framework owns it.

The chokepoint is lint-enforced, not merely conventional: an ESLint no-restricted-imports rule over packages/** and examples/** rejects direct imports of langium, langium/lsp, langium/node, langium/test and vscode-uri (whose URI Langium re-exports and owns the version of). This package itself is exempt, as is any generated directory — langium-cli emits direct imports there and rewrites them on every build, which is also why langium stays a declared dependency of an adopter's own package.

What it gives you

• Langium's full API surface, re-exported: AstNode, AstUtils, URI, UriUtils, the service types, the DI helpers — everything, unfiltered.
• A subpath per upstream subpath, so langium/lsp, langium/node and langium/test each have a chokepoint mirror.
• One ambient type augmentation: AstNode.$synthetic, a marker for a node that was programmatically constructed rather than parsed. Type-level only — the behaviour that reads it lives in @hydranium/core.
• Two additions to the UriUtils namespace, so framework URI helpers sit beside Langium's own: UriUtils.toUri (normalise a URI | string) and UriUtils.isAncestorOrEqual (a scheme- and authority-aware containment check, unlike UriUtils.contains).

Install

npm install @hydranium/langium

No peer dependencies: langium is a direct, exact dependency of this package.

Subpaths

| Subpath | Re-exports | Contents | | -------- | -------------- | ----------------------------------------- | | . | langium | Core API + the framework's augmentations. | | ./lsp | langium/lsp | LSP service defaults. | | ./node | langium/node | NodeFileSystem. | | ./test | langium/test | Parsing / validation test helpers. |

Each named subpath also resolves as @hydranium/langium/lib/<name>, so a consumer on classic moduleResolution: "Node" can reach it.

Usage

Replace langium with @hydranium/langium in your import specifiers; nothing else changes, because the symbols are the same objects.

The one thing to know is that the root entry is side-effecting: importing anything from @hydranium/langium loads the UriUtils augmentation, which mutates the runtime UriUtils object. That is why the added helpers are visible process-wide once any framework package has loaded — and why code that imports UriUtils from langium without ever loading the framework correctly sees only the stock surface.

Status

Alpha — pre-v0, not yet published. The API is Langium's and is stable to the extent Langium's is; what is not yet settled is the augmentation set and the pinned version. See the repository README for the current status and known limitations.

License

MIT — see this package's LICENSE, and the repository NOTICE.md for third-party notices.