Pony Language Server¶

pony-lsp is the Pony Language Server. It communicates with editors via stdout/stdin using the Language Server Protocol. It is part of the ponylang/ponyc repository, built alongside the compiler.

Your editor launches the pony-lsp binary as a subprocess. See the editor configuration section for setup instructions.

Getting pony-lsp¶

pony-lsp is distributed via ponyup alongside ponyc. Installing a recent ponyc will also install pony-lsp. See the ponyc installation instructions for details.

Feature Support¶

Feature	Description
Diagnostics	Compiler errors and warnings published on file open and save
Hover	Type information and documentation on hover
Go To Definition	Jump to the definition of a symbol
Document Symbols	List of symbols in the current file

Workspace Detection¶

pony-lsp needs to know the root of your project so it can resolve packages correctly. It determines this by scanning parent directories for a workspace root marker. The following are recognised as markers:

corral.json (Pony’s dependency manager)
bundle.json
.git, .hg, .bzr, or .svn directories

Most Pony projects will have at least one of these already. If yours doesn’t, create an empty corral.json in the project root or initialise a Git repository there.

Settings¶

pony-lsp supports settings via workspace/configuration request and workspace/didChangeConfiguration notification.

Setting	Type	Example	Description
`defines`	`Array[String]`	`["FOO", "BAR"]`	Defines active during compilation, equivalent to the `-D` flag in `ponyc`
`ponypath`	`Array[String]`	`["/path/to/pony/package"]`	Additional package search paths for pony-lsp

The standard library is discovered automatically from the pony-lsp installation path. You only need ponypath if your project depends on packages outside the standard search locations.

Example settings:

{
  "defines": ["FOO", "BAR"],
  "ponypath": ["/path/to/pony/package", "/another/path"]
}

How to pass these settings depends on your editor. See the editor configuration sections below.

Editor Configuration¶

Helix¶

Getting Helix set up with pony-lsp is very easy. Add the following to your languages.toml.

[[language]]
name = "ponylang"
language-servers = [ "pony-lsp" ]
indent = { tab-width = 2, unit = "  " }

[language-server.pony-lsp]
command = "pony-lsp"
args = [""]

Project-Specific Defines¶

Defines are almost always project-specific. Rather than adding them to your global languages.toml, create a .helix/languages.toml in the project root:

[language-server.pony-lsp.config]
defines = [
  "MY_DEFINE_ONE",
  "MY_DEFINE_TWO",
]

Replace the example values with the actual defines your project needs.

Neovim¶

Configuration details are coming. If you use Neovim with pony-lsp, consider contributing to this section.

Visual Studio Code¶

To get pony-lsp working with Visual Studio Code, first install the Pony VS Code extension. Ensure pony-lsp is on your PATH — the extension will show an error if it isn’t found.

Open your VS Code settings to configure the extension (all options are optional):

{
  "pony.lsp.executable": "/usr/local/bin/pony-lsp",
  "pony.trace.server": "off",
  "pony-lsp.defines": ["FOO", "BAR"],
  "pony-lsp.ponypath": ["/path/to/pony/package1", "/path/to/pony/package2"]
}

pony.lsp.executable sets the path to pony-lsp if it isn’t on your PATH. pony.trace.server traces communication between VS Code and the language server ("off", "messages", or "verbose"). pony-lsp.defines and pony-lsp.ponypath are passed directly to pony-lsp.

For more details, see the Pony VS Code extension project documentation.

Zed¶

To get pony-lsp working with the Zed editor, first install the Pony Zed extension:

Open Zed
Press cmd-shift-x (macOS) or ctrl-shift-x (Linux/Windows)
Search for “Pony”
Click Install

Next, open your Zed settings to configure pony-lsp (all options are optional):

{
  "lsp": {
    "pony-lsp": {
      "settings": {
        "executable": "/pony/bin/pony-lsp",
        "ponypath": [
          "/path/to/project-a/packages",
          "/path/to/project-b/packages"
        ],
        "defines": [
          "MY_DEFINE_ONE",
          "MY_DEFINE_TWO"
        ]
      }
    }
  }
}

For more details, see the Pony Zed extension project documentation.