The instance side of Result: lift a leaf, transform it, fold it. Reach for this when you have a pipeline of transforms; a single branch is usually better served by the leaves alone.
Result.from(res) — the bridge from the simple
layer: lifts an Ok / Bad leaf (or their union) into a Result. It is the
only way to construct one — the constructor is private..map(f) — transform the success value; a failure
passes through untouched, its tag and payload intact..match({ ok, bad }) — collapse both rails to a
single value. The bad arm is a per-reason map (same shape as
matchBad), and each arm is required only when its
rail is inhabited..toUnion() — the inverse of from: drop back to
the Ok | Bad leaf union, where the leaf guards narrow.The wrapper is for chaining, not narrowing — it deliberately has no
isOk() / isBad() guards. See 05 — Chaining with the Result wrapper for a
worked pipeline.