@nowline/core

@nowline/core

Parser, typed AST, and validator for the Nowline DSL. Pure TypeScript, built on Langium, no DOM or Node-specific APIs in the hot path. This package is the foundation everything else in the toolchain (@nowline/layout, @nowline/renderer, @nowline/cli, @nowline/lsp) is built against.

Install

pnpm add @nowline/core

Usage

Parse and validate from a file

import { createNowlineServices, resolveIncludes } from '@nowline/core';
import { URI } from 'langium';
import { readFile } from 'node:fs/promises';

const { shared, Nowline } = createNowlineServices();
const text = await readFile('roadmap.nowline', 'utf-8');
const doc = shared.workspace.LangiumDocumentFactory.fromString(
  text,
  URI.file('/absolute/path/to/roadmap.nowline'),
);
await shared.workspace.DocumentBuilder.build([doc], { validation: true });

const ast = doc.parseResult.value;          // typed AST root: NowlineFile
const parserErrors = doc.parseResult.parserErrors;
const diagnostics = doc.diagnostics ?? [];  // validation errors/warnings

const resolved = await resolveIncludes(ast, '/absolute/path/to/roadmap.nowline', {
  services: Nowline,
});

resolved.config.styles;        // Map<string, StyleDeclaration>
resolved.content.swimlanes;    // Map<string, SwimlaneDeclaration>
resolved.content.isolatedRegions;
resolved.diagnostics;          // Array<ResolveDiagnostic>

Parse from in-memory text

For embedding in editors or one-shot validation against a string:

import { createNowlineServices } from '@nowline/core';
import { URI } from 'langium';

const { shared } = createNowlineServices();
const doc = shared.workspace.LangiumDocumentFactory.fromString(
  text,
  URI.parse('memory:///roadmap.nowline'),
);
await shared.workspace.DocumentBuilder.build([doc], { validation: true });

const ast = doc.parseResult.value;

What's included

• Grammar: src/language/nowline.langium (Langium, indentation-aware).
• AST: generated into src/generated/ast.ts — use isItemDeclaration, isSwimlaneDeclaration, etc. as type guards.
• Validator: 32 validation rules covering file structure, identifiers, property values, include semantics, parallel/group constraints, and more.
• Include resolver: multi-file resolution with merge/ignore/isolate modes, circular-include detection, diamond deduplication.

Regenerate AST

After editing the grammar, regenerate:

pnpm run langium:generate

Test

pnpm test           # one-shot
pnpm test:watch     # watch mode

License

Apache 2.0.