C/C++: replace dot operator with arrow operator intelligently

[GeekZJJ]

I try to use helix to replace vscode to write C/C++ code recently. But I notice that helix can't show the struct member suggestions when I type a . after a struct pointer automatically. I use the same clangd args in vscode, everything works fine. So I'm guessing this is a feature we haven't being implemented currently.
In order to troubleshoot this, I turn on clangd --log=verbose flag and find out helix doesn't send context.triggerCharacter and context.triggerKind to clangd. Maybe it's the root cause of this problem. But I didn't find out how to modify this behavior.

• helix's clangd output

I[12:28:28.089] <-- textDocument/didChange
V[12:28:28.089] <<< {
  "id": 4,
  "jsonrpc": "2.0",
  "method": "textDocument/completion",
  "params": {
    "position": {
      "character": 8,
      "line": 9
    },
    "textDocument": {
      "uri": "file://******/main.c"
    }
  }
}

• vscode's clangd output

I[12:29:34.626] <-- textDocument/didChange
V[12:29:34.652] <<< {
  "id": 24,
  "jsonrpc": "2.0",
  "method": "textDocument/completion",
  "params": {
    "context": {
      "triggerCharacter": ".",
      "triggerKind": 2
    },
    "position": {
      "character": 8,
      "line": 9
    },
    "textDocument": {
      "uri": "file://******/main.c"
    }
  }
}

Originally posted by @GeekZJJ in #9685 (reply in thread)

Discussed in #9685

^{Originally posted by GeekZJJ February 21, 2024}
Hi! I try to use helix to replace vscode to write C/C++ code recently. Everything is good, but I notice that helix can't show the struct member suggestions when I type a . after a struct pointer automatically. I use the same clangd args in vscode, everything works fine. So I'm guessing this is a feature we haven't being implemented currently. Am I right?
My language.toml file is as below:

[language-servers.clangd]
command = "/usr/bin/clangd"
args = ["--pretty", "--background-index", "-j=2", "--clang-tidy", "--clang-tidy-checks=performance-*,bugprone-*", "--all-scopes-completion", "--completion-style=detailed", "--header-insertion=iwyu", "--pch-storage=disk"]

[[language]]
name = "c"
language-servers = ["clangd"]
auto-format = false

Edited:
I found that in the language.toml file I make some mistake, which make clangd's args I configured don't make any sense. The [language-servers.clangd] should be [language-server.clangd]. Correct file is as below.

[language-server.clangd]
command = "/usr/bin/clangd"
args = ["--pretty", "--background-index", "-j=2", "--clang-tidy", "--clang-tidy-checks=performance-*,bugprone-*", "--all-scopes-completion", "--completion-style=detailed", "--header-insertion=iwyu", "--pch-storage=disk"]

[[language]]
name = "c"
language-servers = ["clangd"]
auto-format = false

[the-mikedavis]

No need to duplicate the discussion. If we can narrow down the exact cause of the difference between vscode and helix then we can make an issue focusing on that but this is just fragmenting the debugging discussion

[pascalkuthe]

• the issue is also not reproducible C/C++: replace dot operator with arrow operator intelligently #9685 (reply in thread). The completion context usually doesn't matter much
• we do send completion context since Add an event system #8021 as also noted in that discussion

[GeekZJJ]

@the-mikedavis Got that. So sorry for my duplicate post.
@pascalkuthe Maybe that is because of my out of date helix version. I will try it when ppa:maveonair/helix-editor have an update version with the commit mentioned above. Thanks.