Method refine

repos/effect/packages/effect/src/Optic.ts:1086–1088

(refinement: (a: A) => a is B, annotations?: Schema.Annotations.Filter)

          return bs
        }),
      // SET: bs must match the number of focusable elements
      (bs, s) =>
        Result.flatMap(this.getResult(s), (as) => {
          // 1) collect focusable indices
          const idxs: Array<number> = []
          for (let i = 0; i < as.length; i++) {