More control on typed holes (for navigation)

[xvw]

At the moment, there is only one request to return the list of typed holes, which means that a lot of client-side logic has to be implemented. For example, in ocaml-eglot (see):

;; Holes

;; TODO: It would probably be possible to improve the query to embed
;; more logic at the `merlin-lib` level rather than calculating hole
;; logic at the editor level.

(defun ocaml-eglot--first-hole-aux (holes pos comparison)
  "Return the first hole of the list HOLES since a POS using COMPARISON."
  (when (or holes (not (equal [] holes)))
    (let* ((hd (car holes))
           (tl (cdr holes))
           (h-start (cl-getf hd :start))
           (cmp (ocaml-eglot-util--compare-position h-start pos)))
      (if (funcall comparison cmp 0) hd
        (ocaml-eglot--first-hole-aux tl pos comparison)))))

(defun ocaml-eglot--first-hole-at (holes pos comparison)
  "Return the first hole of the list HOLES since a POS using COMPARISON.
If there is no available holes, it returns the first one of HOLES."
  (let ((hole (ocaml-eglot--first-hole-aux holes pos comparison)))
    (if hole hole (car holes))))

(defun ocaml-eglot--get-first-hole-in (start end)
  "Return the first hole in a given range denoted by START and END."
  (let* ((holes (ocaml-eglot-req--holes))
         (hole (ocaml-eglot--first-hole-at holes start '>=)))
    (when hole
      (let ((hole-start (cl-getf hole :start))
            (hole-end (cl-getf hole :end)))
        (when (and (>= (ocaml-eglot-util--compare-position hole-start start) 0)
                   (<= (ocaml-eglot-util--compare-position hole-end end) 0))
          hole)))))

(defun ocaml-eglot--first-hole-in (start end)
  "Jump to the first hole in a given range denoted by START and END."
  (when-let* ((hole (ocaml-eglot--get-first-hole-in start end))
              (hole-start (cl-getf hole :start)))
    (ocaml-eglot-util--jump-to hole-start)))

(defun ocaml-eglot-hole-prev ()
  "Jump to the previous hole."
  (interactive)
  (ocaml-eglot-req--server-capable-or-lose :experimental :ocamllsp :handleTypedHoles)
  (let* ((current-pos (eglot--pos-to-lsp-position))
         (holes (reverse (ocaml-eglot-req--holes)))
         (hole (ocaml-eglot--first-hole-at holes current-pos '<)))
    (when hole (ocaml-eglot-util--jump-to-range hole))))

(defun ocaml-eglot-hole-next ()
  "Jump to the next hole."
  (interactive)
  (ocaml-eglot-req--server-capable-or-lose :experimental :ocamllsp :handleTypedHoles)
  (let* ((current-pos (eglot--pos-to-lsp-position))
         (holes (ocaml-eglot-req--holes))
         (hole (ocaml-eglot--first-hole-at holes current-pos '>)))
    (when hole (ocaml-eglot-util--jump-to-range hole))))

This patch allows the next/previous hole to be related to a given piece of contextual information. It is possible to include a range to return a hole only in a given range.

(cc @awilliambauer)

[coveralls]

Pull Request Test Coverage Report for Build 4833

Details

• 51 of 60 (85.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 23.15%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
ocaml-lsp-server/src/typed_hole.ml	24	25	96.0%
ocaml-lsp-server/src/custom_requests/req_typed_holes.ml	0	2	0.0%
ocaml-lsp-server/src/custom_requests/req_jump_to_typed_hole.ml	27	33	81.82%

Totals
Change from base Build 4826:	0.2%
Covered Lines:	5934
Relevant Lines:	25633

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💛 - Coveralls

[voodoos]

Thanks, I agree that moving this logic to the server is useful: these position based tricks are frequent footguns so it's good that client implementers can just trust the server instead of re-implementing it.