Enough to recognise a value by: where it is written, what was written above it, and its signature. null where this session knows nothing by that name. What .doc prints.

In the order a file has them — where it is, what was said about it, then the thing itself. A value with no comment still has the other two, which is the difference between "here it is" and the "nothing written about it" this used to answer.

import { summarizeValue } from './value-details.ts';

import type { ReplContext } from './command.ts';

// Defined, not invoked: it asks a live page where something came from.
function example(repl: ReplContext) {
  return summarizeValue(repl, 'double');
  // 'test/fixtures/repl-helpers.ts:15\nDoubles a number…\nexport function double(…)'
}