Is the code completion supports $0 as the final cursor position?

[goofansu]

I'm using Eglot with ruby-lsp. ruby-lsp will insert a $0 as the final cursor position according to the VS Code's snippet syntax in some cases, see Shopify/ruby-lsp#1269 (comment) for details.

Does Eglot recognize the $0 as the final cursor position? Thanks

[joaotavora]

This is likely not an Eglot issue. Eglot is not a snippet parser, it uses Yasnippet. Yes yasnippet knows about $0 no problem.

I'm really sure this issue was discussed in this repository or something nearby not too long ago, but I can't find that forum. Anyway, without more information, it's impossible to say more.

[goofansu]

@joaotavora ruby-lsp inserts the character, I didn’t install yasnippet because I’m using tempel, I’ll install it and see if the $0 is recognized.

[joaotavora]

Egot doesn't integrate with tempel sorry, only yasnippet. Does templet support Textmate snippet syntax?

[goofansu]

@joaotavora No worry, I owe you a big thank you for making Eglot and yasnippet.

Tempel uses the syntax of the Emacs Tempo library, so not support textmate snippet syntax. Ref: minad/tempel#109 (comment)

[goofansu]

From the Eglot events log, the server returns a :newText in [server-reply] (id:94), then the client does a textDocument/didChange event to insert $0, so it seems none of the business of completion.

(:jsonrpc "2.0" :method "textDocument/didChange" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb" :version 35)
           :contentChanges
           [(:range
             (:start
              (:line 0 :character 0)
              :end
              (:line 0 :character 0))
             :rangeLength 0 :text "d")]))
[client-request] (id:93) Wed Jan  3 11:55:02 2024:
(:jsonrpc "2.0" :id 93 :method "textDocument/onTypeFormatting" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb")
           :options
           (:tabSize 8 :insertSpaces t :insertFinalNewline t :trimFinalNewlines t)
           :position
           (:line 0 :character 1)
           :ch "d"))
[server-reply] (id:93) Wed Jan  3 11:55:02 2024:
(:id 93 :result
     []
     :jsonrpc "2.0")
[client-notification] Wed Jan  3 11:55:03 2024:
(:jsonrpc "2.0" :method "textDocument/didChange" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb" :version 40)
           :contentChanges
           [(:range
             (:start
              (:line 0 :character 1)
              :end
              (:line 0 :character 1))
             :rangeLength 0 :text "o")
            (:range
             (:start
              (:line 0 :character 2)
              :end
              (:line 0 :character 2))
             :rangeLength 0 :text " ")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text "end")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text "\n")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text "|")]))
[client-request] (id:94) Wed Jan  3 11:55:03 2024:
(:jsonrpc "2.0" :id 94 :method "textDocument/onTypeFormatting" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb")
           :options
           (:tabSize 8 :insertSpaces t :insertFinalNewline t :trimFinalNewlines t)
           :position
           (:line 0 :character 4)
           :ch "|"))
[server-reply] (id:94) Wed Jan  3 11:55:03 2024:
(:id 94 :result
     [(:range
       (:start
        (:line 0 :character 4)
        :end
        (:line 0 :character 4))
       :newText "|")
      (:range
       (:start
        (:line 0 :character 4)
        :end
        (:line 0 :character 4))
       :newText "$0")]
     :jsonrpc "2.0")
[client-notification] Wed Jan  3 11:55:04 2024:
(:jsonrpc "2.0" :method "textDocument/didChange" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb" :version 50)
           :contentChanges
           [(:range
             (:start
              (:line 0 :character 4)
              :end
              (:line 0 :character 4))
             :rangeLength 0 :text "$0")
            (:range
             (:start
              (:line 0 :character 4)
              :end
              (:line 0 :character 4))
             :rangeLength 0 :text "|")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 4))
             :rangeLength 1 :text "")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text " ")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 4))
             :rangeLength 1 :text "")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text "|")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 4))
             :rangeLength 1 :text "")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text " ")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 4))
             :rangeLength 1 :text "")
            (:range
             (:start
              (:line 0 :character 3)
              :end
              (:line 0 :character 3))
             :rangeLength 0 :text "|")]))

[joaotavora]

Yup this part of the interactiion is odd. You type a |, ask the server if there's any formatting it would like to do (which is normally whitespace additions), and it replies back with a $0. There's no snippet protocol for onTypeFormatting as far as I know:

[client-request] (id:94) Wed Jan  3 11:55:03 2024:
(:jsonrpc "2.0" :id 94 :method "textDocument/onTypeFormatting" :params
          (:textDocument
           (:uri "file:///Users/james/work/myproj/demo.rb")
           :options
           (:tabSize 8 :insertSpaces t :insertFinalNewline t :trimFinalNewlines t)
           :position
           (:line 0 :character 4)
           :ch "|"))
[server-reply] (id:94) Wed Jan  3 11:55:03 2024:
(:id 94 :result
     [(:range
       (:start
        (:line 0 :character 4)
        :end
        (:line 0 :character 4))
       :newText "|")
      (:range
       (:start
        (:line 0 :character 4)
        :end
        (:line 0 :character 4))
       :newText "$0")]
     :jsonrpc "2.0")

[goofansu]

@joaotavora Yes, it is not related to snippet. I'll discuss the problem in the ruby-lsp issue. Thank you!