tricu

io-profile.ts (3324B)

---

 // This table is the implemented browser provider, not the native catalogue.
 import { canonicalNat, decodeAction, ProtocolError, type Reader } from './io-protocol.js';
 import type { Wire } from './io-core.js';
 export const coreNames = ['pure', 'bind', 'fail', 'scope', 'current-scope', 'spawn', 'join', 'discard', 'cancel', 'cancelled'] as const;
 const groups: Readonly<Record<string, readonly string[]>> = Object.freeze({
   runtime: ['capabilities', 'inspect'], standard: ['input', 'output', 'error'],
   stream: ['read', 'write'], resource: ['close'], utf8: ['encode', 'decode'],
 });
 export function available(group: string, revision: number, operation: string): boolean {
   return revision === 1 && Object.hasOwn(groups, group) && groups[group]!.includes(operation);
 }
 export function capabilities<H>(wire: Wire<H>, backend: string): H {
   const { tree } = wire, text = (s: string) => tree.text(s), number = (n: number) => tree.natural(BigInt(n));
   const strings = (xs: readonly string[]) => wire.list(xs.map(text)), row = (name: string, value: H) => wire.list([text(name), value]);
   return wire.list([
     row('schema', number(1)), row('io-version', number(2)), row('backend', text(backend)), row('authority', text('browser-terminal')),
     row('core', strings(coreNames)), row('groups', wire.list(Object.entries(groups).map(([name, ops]) => wire.list([text(name), number(1), strings(ops)])))),
     row('limits', wire.list(Object.entries({ 'io-actions': 65536, 'chunk-bytes': 4096, 'transfer-handles': 256, 'utf8-encode-scalars': 1024, 'input-line-scalars': 256, 'output-attempted-bytes': 16384 }).map(([key, value]) => row(key, number(value))))),
     row('restrictions', strings(['action-boundary-cancellation', 'no-hard-deadlines', 'borrowed-standard-streams', 'standard-stream-leases-per-run', 'utf8-strict-scalars', 'text-line-input', 'byte-preserving-output', 'no-filesystem', 'no-network', 'no-processes'])),
   ]);
 }
 export function inspect<H>(wire: Wire<H>, value: H): H {
   const action = decodeAction(wire.tree, value), t = wire.tree;
   return action.kind === 'core' ? wire.list([t.text('core'), t.text(coreNames[action.code]!)]) :
     wire.list([t.text('facility'), t.text(action.group), t.natural(BigInt(action.revision)), t.text(action.operation), t.text(available(action.group, action.revision, action.operation) ? 'available' : 'unsupported')]);
 }
 // Authenticate framing before selecting an interpreter. No action is observed.
 export function envelope<H>(tree: Reader<H>, value: H): { version: 2; action: H } {
   const root = tree.observe(value).node;
   if (root.kind !== 'fork') throw new ProtocolError('invalid IO envelope');
   let rest = root.left;
   for (const char of 'tricuIO') {
     const node = tree.observe(rest).node;
     if (node.kind !== 'fork' || canonicalNat(tree, node.left, 7) !== BigInt(char.charCodeAt(0))) throw new ProtocolError('Missing tricuIO sentinel');
     rest = node.right;
   }
   if (tree.observe(rest).node.kind !== 'leaf') throw new ProtocolError('Missing tricuIO sentinel');
   const body = tree.observe(root.right).node;
   if (body.kind !== 'fork') throw new ProtocolError('invalid IO envelope');
   const version = canonicalNat(tree, body.left, 2);
   if (version !== 2n) throw new ProtocolError('Unsupported tricuIO version');
   return { version: 2, action: body.right };
 }