bug#60407: [PATCH] Update go-ts-mode to use Imenu facility

[Evgeni Kolev]

Hi Randy,

I'm providing the updated patch - I've addressed your comments and
also added Electric Pair mode settings (variable
electric-indent-chars).

Thanks for your feedback. Again, please let me know if the patch can
be improved.

The patch is below.

commit c38df01b088c3fdc0b86340a230b7397b5c81317
Author: Evgeni Kolev <evgenysw@gmail.com>
Date:   Thu Dec 29 17:49:40 2022 +0200

    Improve go-ts-mode Imenu, navigation and electric pair configuration

    The Imenu items are extended to support "Method", "Struct",
    "Interface", "Alias" and "Type".

    go-ts-mode is updated to use the Imenu facility added in commit
    b39dc7ab27a696a8607ab859aeff3c71509231f5.

    Variable electric-indent-chars is set in order to improve integration
    with Electric Pair mode.

    * lisp/progmodes/go-ts-mode.el (go-ts-mode--imenu-1) (go-ts-mode--imenu):
    Remove functions.
    (go-ts-mode--defun-name, go-ts-mode--interface-node-p)
    (go-ts-mode--struct-node-p, go-ts-mode--other-type-node-p)
    (go-ts-mode--alias-node-p): New functions.
    (go-ts-mode): Improve Imenu settings, navigation, add Electric Pair
    mode settings.

diff --git a/lisp/progmodes/go-ts-mode.el b/lisp/progmodes/go-ts-mode.el
index 1d6a8a30db5..64e761d2f72 100644
--- a/lisp/progmodes/go-ts-mode.el
+++ b/lisp/progmodes/go-ts-mode.el
@@ -36,6 +36,7 @@
 (declare-function treesit-node-child-by-field-name "treesit.c")
 (declare-function treesit-node-start "treesit.c")
 (declare-function treesit-node-type "treesit.c")
+(declare-function treesit-search-subtree "treesit.c")

 (defcustom go-ts-mode-indent-offset 4
   "Number of spaces for each indentation step in `go-ts-mode'."
@@ -173,44 +174,6 @@ go-ts-mode--font-lock-settings
    '((ERROR) @font-lock-warning-face))
   "Tree-sitter font-lock settings for `go-ts-mode'.")

-(defun go-ts-mode--imenu ()
-  "Return Imenu alist for the current buffer."
-  (let* ((node (treesit-buffer-root-node))
-         (func-tree (treesit-induce-sparse-tree
-                     node "function_declaration" nil 1000))
-         (type-tree (treesit-induce-sparse-tree
-                     node "type_spec" nil 1000))
-         (func-index (go-ts-mode--imenu-1 func-tree))
-         (type-index (go-ts-mode--imenu-1 type-tree)))
-    (append
-     (when func-index `(("Function" . ,func-index)))
-     (when type-index `(("Type" . ,type-index))))))
-
-(defun go-ts-mode--imenu-1 (node)
-  "Helper for `go-ts-mode--imenu'.
-Find string representation for NODE and set marker, then recurse
-the subtrees."
-  (let* ((ts-node (car node))
-         (children (cdr node))
-         (subtrees (mapcan #'go-ts-mode--imenu-1
-                           children))
-         (name (when ts-node
-                 (treesit-node-text
-                  (pcase (treesit-node-type ts-node)
-                    ("function_declaration"
-                     (treesit-node-child-by-field-name ts-node "name"))
-                    ("type_spec"
-                     (treesit-node-child-by-field-name ts-node "name"))))))
-         (marker (when ts-node
-                   (set-marker (make-marker)
-                               (treesit-node-start ts-node)))))
-    (cond
-     ((or (null ts-node) (null name)) subtrees)
-     (subtrees
-      `((,name ,(cons name marker) ,@subtrees)))
-     (t
-      `((,name . ,marker))))))
-
 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.go\\'" . go-ts-mode))

@@ -228,14 +191,30 @@ go-ts-mode
     (setq-local comment-end "")
     (setq-local comment-start-skip (rx "//" (* (syntax whitespace))))

+    ;; Navigation.
+    (setq-local treesit-defun-type-regexp
+                (regexp-opt '("method_declaration"
+                              "function_declaration"
+                              "type_declaration")))
+    (setq-local treesit-defun-name-function #'go-ts-mode--defun-name)
+
     ;; Imenu.
-    (setq-local imenu-create-index-function #'go-ts-mode--imenu)
-    (setq-local which-func-functions nil)
+    (setq-local treesit-simple-imenu-settings
+                `(("Function" "\\`function_declaration\\'" nil nil)
+                  ("Method" "\\`method_declaration\\'" nil nil)
+                  ("Struct" "\\`type_declaration\\'"
go-ts-mode--struct-node-p nil)
+                  ("Interface" "\\`type_declaration\\'"
go-ts-mode--interface-node-p nil)
+                  ("Type" "\\`type_declaration\\'"
go-ts-mode--other-type-node-p nil)
+                  ("Alias" "\\`type_declaration\\'"
go-ts-mode--alias-node-p nil)))

     ;; Indent.
     (setq-local indent-tabs-mode t
                 treesit-simple-indent-rules go-ts-mode--indent-rules)

+    ;; Electric
+    (setq-local electric-indent-chars
+                (append "{}()" electric-indent-chars))
+
     ;; Font-lock.
     (setq-local treesit-font-lock-settings go-ts-mode--font-lock-settings)
     (setq-local treesit-font-lock-feature-list
@@ -247,6 +226,54 @@ go-ts-mode

     (treesit-major-mode-setup)))

+(defun go-ts-mode--defun-name (node)
+  "Return the defun name of NODE.
+Return nil if there is no name or if NODE is not a defun node."
+  (pcase (treesit-node-type node)
+    ("function_declaration"
+     (treesit-node-text
+      (treesit-node-child-by-field-name
+       node "name")
+      t))
+    ("method_declaration"
+     (let* ((receiver-node (treesit-node-child-by-field-name node "receiver"))
+            (type-node (treesit-search-subtree receiver-node
"type_identifier"))
+            (name-node (treesit-node-child-by-field-name node "name")))
+       (concat
+        "(" (treesit-node-text type-node) ")."
+        (treesit-node-text name-node))))
+    ("type_declaration"
+     (treesit-node-text
+      (treesit-node-child-by-field-name
+       (treesit-node-child node 0 t) "name")
+      t))))
+
+(defun go-ts-mode--interface-node-p (node)
+  "Return t if NODE is an interface."
+  (and
+   (string-equal "type_declaration" (treesit-node-type node))
+   (treesit-search-subtree node "interface_type" nil nil 2)))
+
+(defun go-ts-mode--struct-node-p (node)
+  "Return t if NODE is a struct."
+  (and
+   (string-equal "type_declaration" (treesit-node-type node))
+   (treesit-search-subtree node "struct_type" nil nil 2)))
+
+(defun go-ts-mode--alias-node-p (node)
+  "Return t if NODE is a type alias."
+  (and
+   (string-equal "type_declaration" (treesit-node-type node))
+   (treesit-search-subtree node "type_alias" nil nil 1)))
+
+(defun go-ts-mode--other-type-node-p (node)
+  "Return t if NODE is a type, other than interface, struct or alias."
+  (and
+   (string-equal "type_declaration" (treesit-node-type node))
+   (not (go-ts-mode--interface-node-p node))
+   (not (go-ts-mode--struct-node-p node))
+   (not (go-ts-mode--alias-node-p node))))
+
 ;; go.mod support.

 (defvar go-mod-ts-mode--syntax-table

On Tue, Jan 3, 2023 at 4:31 PM Randy Taylor <dev@rjt.dev> wrote:
>
> On Tuesday, January 3rd, 2023 at 04:01, Evgeni Kolev <evgenysw@gmail.com> 
> wrote:
> >
> > Hi Randy, thank you for your feedback!
> >
> > I'm providing an updated patch below. I tested with "type Quack int"
> > and other cases such as:
> > type MyInt = int
> > type Option func(s string)
> > type List[T any] struct {
> > head, tail *element[T]
> > }
> > type Number interface {
> > int64 | float64
> > }
> >
> > After experimenting, I decided to add additional Imenu categories:
> > "Alias" and "Type".
> > So the final list of newly added categories is "Method", "Struct",
> > "Interface", "Alias" and "Type".
>
> Sounds good to me.
>
> It looks like the alias type MyInt = int shows up in both categories: Alias 
> and Type.
> It should probably belong just in the Alias category.
>
> >
> > Structs and interfaces are technically a private case for "Type", but
> > are put in their own Imenu category.
> > Hence the "Type" category now holds all types except structs,
> > interfaces and aliases (aliases have their own tree sitter type
> > defined in Go's grammar.js).
> >
> > For reference, eglot's Imenu uses category "Class" instead of "Type".
> > But I decided to not replicate this behavior - "Class" is not a widely
> > used Go concept.
> > However, I decided to replicate another eglot behaviour - prefixing
> > the method names with the type of the receiver (for example,
> > "(rect).area" for "func (r rect) area() float64...").
>
> Great! I was going to suggest that but forgot.
>
> >
> > I've also addressed the other comments. I'm a bit unsure how the git
> > commit should be formatted - the part of the message which describes
> > changed functions/files.
> >
> > Please let me know if the patch can be improved. The patch is below.
>
> Comments below.
>
> >
> > commit a96e70052a79881ac666ab699ffd63ed916eaf83
> > Author: Evgeni Kolev evgenysw@gmail.com
> >
> > Date: Thu Dec 29 17:49:40 2022 +0200
> >
> > Improve go-ts-mode Imenu
>
> Maybe this should also say "and add navigation support" (or something 
> similar)?
>
> >
> > The Imenu items are extended to support "Method", "Struct",
> > "Interface", "Alias" and "Type".
> >
> > go-ts-mode is updated to use the Imenu facility added in commit
> > b39dc7ab27a696a8607ab859aeff3c71509231f5.
> >
> > * lisp/progmodes/go-ts-mode.el (go-ts-mode--imenu-1) (go-ts-mode--imenu):
> > Remove functions.
> > (go-ts-mode--defun-name) (go-ts-mode--interface-node-p)
>
> I'm no commit format expert, but I think this can be (go-ts-mode--defun-name, 
> go-ts-mode--interface-node-p)
> Whenever it fits on a single line, you can combine them like that. Same for 
> the line below.
>
> > (go-ts-mode--struct-node-p) (go-ts-mode--other-type-node-p)
> > (go-ts-mode--alias-node-p): New functions.
> > (go-ts-mode): Improve Imenu settings.
>
> I think the (go-ts-mode) part should mention that navigation support was 
> added.
>
> >
> > diff --git a/lisp/progmodes/go-ts-mode.el b/lisp/progmodes/go-ts-mode.el
> > index 1d6a8a30db5..d91b555e03e 100644
> > --- a/lisp/progmodes/go-ts-mode.el
> > +++ b/lisp/progmodes/go-ts-mode.el
> > @@ -173,44 +173,6 @@ go-ts-mode--font-lock-settings
> > '((ERROR) @font-lock-warning-face))
> > "Tree-sitter font-lock settings for `go-ts-mode'.") -(defun 
> > go-ts-mode--imenu () - "Return Imenu alist for the current buffer." - (let* 
> > ((node (treesit-buffer-root-node)) - (func-tree (treesit-induce-sparse-tree 
> > - node "function_declaration" nil 1000)) - (type-tree 
> > (treesit-induce-sparse-tree - node "type_spec" nil 1000)) - (func-index 
> > (go-ts-mode--imenu-1 func-tree)) - (type-index (go-ts-mode--imenu-1 
> > type-tree))) - (append - (when func-index` (("Function" . ,func-index)))
> > - (when type-index `(("Type" . ,type-index)))))) - -(defun 
> > go-ts-mode--imenu-1 (node) - "Helper for` go-ts-mode--imenu'.
> > -Find string representation for NODE and set marker, then recurse
> > -the subtrees."
> > - (let* ((ts-node (car node))
> > - (children (cdr node))
> > - (subtrees (mapcan #'go-ts-mode--imenu-1
> > - children))
> > - (name (when ts-node
> > - (treesit-node-text
> > - (pcase (treesit-node-type ts-node)
> > - ("function_declaration"
> > - (treesit-node-child-by-field-name ts-node "name"))
> > - ("type_spec"
> > - (treesit-node-child-by-field-name ts-node "name"))))))
> > - (marker (when ts-node
> > - (set-marker (make-marker)
> > - (treesit-node-start ts-node)))))
> > - (cond
> > - ((or (null ts-node) (null name)) subtrees)
> > - (subtrees
> > - `((,name ,(cons name marker) ,@subtrees))) - (t -` ((,name . ,marker))))))
> > -
> > ;;;###autoload
> > (add-to-list 'auto-mode-alist '("\\.go\\'" . go-ts-mode))
> >
> > @@ -228,9 +190,21 @@ go-ts-mode
> > (setq-local comment-end "")
> > (setq-local comment-start-skip (rx "//" (* (syntax whitespace))))
> >
> > + ;; Navigation.
> > + (setq-local treesit-defun-type-regexp
> > + (regexp-opt '("method_declaration"
> > + "function_declaration"
> > + "type_declaration")))
> > + (setq-local treesit-defun-name-function #'go-ts-mode--defun-name)
> > +
> > ;; Imenu.
> > - (setq-local imenu-create-index-function #'go-ts-mode--imenu)
> > - (setq-local which-func-functions nil)
> > + (setq-local treesit-simple-imenu-settings
> > + `(("Function" "\\\\`function_declaration\\'" nil nil)
> > + ("Method" "\\`method_declaration\\\\'" nil nil) + ("Struct" 
> > "\\\\`type_declaration\\'"
> > go-ts-mode--struct-node-p nil)
> > + ("Interface" "\\`type_declaration\\\\'" go-ts-mode--interface-node-p nil) 
> > + ("Type" "\\\\`type_declaration\\'"
> > go-ts-mode--other-type-node-p nil)
> > + ("Alias" "\\`type_declaration\\'"
> > go-ts-mode--alias-node-p nil)))
> >
> > ;; Indent.
> > (setq-local indent-tabs-mode t
> > @@ -247,6 +221,53 @@ go-ts-mode
> >
> > (treesit-major-mode-setup)))
> >
> > +(defun go-ts-mode--defun-name (node)
> > + "Return the defun name of NODE.
> > +Return nil if there is no name or if NODE is not a defun node."
> > + (pcase (treesit-node-type node)
> > + ("function_declaration"
> > + (treesit-node-text
> > + (treesit-node-child-by-field-name
> > + node "name")
> > + t))
> > + ("method_declaration"
> > + (let* ((receiver-node (treesit-node-child-by-field-name node "receiver"))
> > + (type-node (treesit-search-subtree receiver-node
> > "type_identifier"))
> > + (name-node (treesit-node-child-by-field-name node "name")))
> > + (concat
> > + "(" (treesit-node-text type-node) ")."
> > + (treesit-node-text name-node))))
> > + ("type_declaration"
> > + (treesit-node-text
> > + (treesit-node-child-by-field-name
> > + (treesit-node-child node 0 t) "name")
> > + t))))
> > +
> > +(defun go-ts-mode--interface-node-p (node)
> > + "Return t if NODE is an interface."
> > + (and
> > + (string-equal "type_declaration" (treesit-node-type node))
> > + (treesit-search-subtree node "interface_type" nil nil 2)))
>
> I think you need to add (declare-function treesit-search-subtree "treesit.c") 
> after the last one at the top of the file.
>
> > +
> > +(defun go-ts-mode--struct-node-p (node)
> > + "Return t if NODE is a struct."
> > + (and
> > + (string-equal "type_declaration" (treesit-node-type node))
> > + (treesit-search-subtree node "struct_type" nil nil 2)))
> > +
> > +(defun go-ts-mode--alias-node-p (node)
> > + "Return t if NODE is a type alias."
> > + (and
> > + (string-equal "type_declaration" (treesit-node-type node))
> > + (treesit-search-subtree node "type_alias" nil nil 1)))
> > +
> > +(defun go-ts-mode--other-type-node-p (node)
> > + "Return t if NODE is a type, other than interface or struct."
> > + (and
> > + (string-equal "type_declaration" (treesit-node-type node))
> > + (not (go-ts-mode--interface-node-p node))
> > + (not (go-ts-mode--struct-node-p node))))
>
> Here I guess we just need a (not alias) (and the docstring updated) to fix 
> the issue mentioned above.
>
> > +
> > ;; go.mod support.
> >
> > (defvar go-mod-ts-mode--syntax-table
> >