defmodule GenLSP do
@moduledoc "README.md"
|> File.read!()
|> String.split("<!-- MDOC !-->")
|> Enum.fetch!(1)
alias GenLSP.LSP
defmacro __using__(_) do
quote do
@behaviour GenLSP
require Logger
import GenLSP.LSP
def child_spec(opts) do
%{
id: __MODULE__,
start: {__MODULE__, :start_link, [opts]},
type: :worker,
restart: :permanent,
shutdown: 500
}
end
@impl true
def handle_info(_, state) do
Logger.warn("Unhandled message passed to handle_info/2")
{:noreply, state}
end
defoverridable handle_info: 2
end
end
require Logger
@doc """
The callback responsible for initializing the process.
Receives the `t:GenLSP.LSP.t/0` token as the first argument and the arguments that were passed to `GenLSP.start_link/3` as the second.
## Usage
```elixir
@impl true
def init(lsp, args) do
some_arg = Keyword.fetch!(args, :some_arg)
{:ok, assign(lsp, static_assign: :some_assign, some_arg: some_arg)}
end
```
"""
@callback init(lsp :: GenLSP.LSP.t(), init_arg :: term()) :: {:ok, GenLSP.LSP.t()}
@doc """
The callback responsible for handling requests from the client.
Receives the request struct as the first argument and the LSP token `t:GenLSP.LSP.t/0` as the second.
## Usage
```elixir
@impl true
def handle_request(%Initialize{params: %InitializeParams{root_uri: root_uri}}, lsp) do
{:reply,
%InitializeResult{
capabilities: %ServerCapabilities{
text_document_sync: %TextDocumentSyncOptions{
open_close: true,
save: %SaveOptions{include_text: true},
change: TextDocumentSyncKind.full()
}
},
server_info: %{name: "MyLSP"}
}, assign(lsp, root_uri: root_uri)}
end
```
"""
@callback handle_request(request :: term(), state) ::
{:reply, id :: integer(), reply :: term(), state} | {:noreply, state}
when state: GenLSP.LSP.t()
@doc """
The callback responsible for handling notifications from the client.
Receives the notification struct as the first argument and the LSP token `t:GenLSP.LSP.t/0` as the second.
## Usage
```elixir
@impl true
def handle_notification(%Initialized{}, lsp) do
# handle the notification
{:noreply, lsp}
end
```
"""
@callback handle_notification(notification :: term(), state) :: {:noreply, state}
when state: GenLSP.LSP.t()
@doc """
The callback responsible for handling normal messages.
Receives the notification struct as the first argument and the LSP token `t:GenLSP.LSP.t/0` as the second.
## Usage
```elixir
@impl true
def handle_info(message, lsp) do
# handle the message
{:noreply, lsp}
end
```
"""
@callback handle_info(message :: any(), state) :: {:noreply, state} when state: GenLSP.LSP.t()
@options_schema NimbleOptions.new!(
buffer: [
type: {:or, [:pid, :atom]},
required: true,
doc: "The `t:pid/0` or name of the `GenLSP.Buffer` process."
],
name: [
type: :atom,
doc:
"Used for name registration as described in the \"Name registration\" section in the documentation for `GenServer`."
]
)
@doc """
Starts a `GenLSP` process that is linked to the current process.
## Options
#{NimbleOptions.docs(@options_schema)}
"""
def start_link(module, init_args, opts) do
opts = NimbleOptions.validate!(opts, @options_schema)
:proc_lib.start_link(__MODULE__, :init, [
{module, init_args, Keyword.take(opts, [:name, :buffer]), self()}
])
end
@doc false
def init({module, init_args, opts, parent}) do
me = self()
buffer = Keyword.get(opts, :buffer, GenLSP.Buffer)
lsp = %LSP{mod: module, pid: me, buffer: buffer}
case module.init(lsp, init_args) do
{:ok, %LSP{} = lsp} ->
deb = :sys.debug_options([])
if opts[:name], do: Process.register(self(), opts[:name])
:proc_lib.init_ack(parent, {:ok, me})
GenLSP.Buffer.listen(buffer, me)
loop(lsp, parent, deb)
end
end
@doc """
Sends a request from the client to the LSP process.
Generally used by the `GenLSP.Communication.Adapter` implementation to forward messages from the buffer to the LSP process.
You shouldn't need to use this to implement a language server.
"""
@spec request_server(pid(), message) :: message when message: term()
def request_server(pid, request) do
from = self()
message = {:request, from, request}
send(pid, message)
end
@doc """
Sends a notification from the client to the LSP process.
Generally used by the `GenLSP.Communication.Adapter` implementation to forward messages from the buffer to the LSP process.
You shouldn't need to use this to implement a language server.
"""
@spec notify_server(pid(), message) :: message when message: term()
def notify_server(pid, notification) do
from = self()
send(pid, {:notification, from, notification})
end
@doc """
Sends a notification to the client from the LSP process.
## Usage
```elixir
GenLSP.notify(lsp, %TextDocumentPublishDiagnostics{
params: %PublishDiagnosticsParams{
uri: "file://#\{file}",
diagnostics: diagnostics
}
})
```
"""
@spec notify(GenLSP.LSP.t(), notification :: any()) :: :ok
def notify(%{buffer: buffer}, notification) do
GenLSP.Buffer.outgoing(buffer, dump!(notification))
end
defp write_debug(device, event, name) do
IO.write(device, "#{inspect(name)} event = #{inspect(event)}")
end
defp loop(%LSP{} = lsp, parent, deb) do
receive do
{:system, from, request} ->
:sys.handle_system_msg(request, from, parent, __MODULE__, deb, lsp)
{:request, from, request} ->
deb = :sys.handle_debug(deb, &write_debug/3, __MODULE__, {:in, :request, from})
attempt(
fn ->
{:ok, %{id: id} = req} = GenLSP.Requests.new(request)
GenLSP.log(lsp, :log, "[GenLSP] Processing #{inspect(req.__struct__)}")
case lsp.mod.handle_request(req, lsp) do
{:reply, reply, %LSP{} = lsp} ->
packet = %{
"jsonrpc" => "2.0",
"id" => id,
"result" => dump!(reply)
}
deb = :sys.handle_debug(deb, &write_debug/3, __MODULE__, {:out, :request, from})
GenLSP.Buffer.outgoing(lsp.buffer, packet)
loop(lsp, parent, deb)
{:noreply, lsp} ->
loop(lsp, parent, deb)
end
end,
"Last message received: handle_request #{inspect(request)}"
)
{:notification, from, notification} ->
deb = :sys.handle_debug(deb, &write_debug/3, __MODULE__, {:in, :notification, from})
attempt(
fn ->
{:ok, note} = GenLSP.Notifications.new(notification)
GenLSP.log(lsp, :log, "[GenLSP] Processing #{inspect(note.__struct__)}")
case lsp.mod.handle_notification(note, lsp) do
{:noreply, %LSP{} = lsp} ->
loop(lsp, parent, deb)
end
end,
"Last message received: handle_notification #{inspect(notification)}"
)
message ->
attempt(
fn ->
case lsp.mod.handle_info(message, lsp) do
{:noreply, %LSP{} = lsp} ->
loop(lsp, parent, deb)
end
end,
"Last message received: handle_info #{inspect(message)}"
)
end
end
@spec attempt((() -> any()), String.t()) :: no_return()
defp attempt(callback, message) do
callback.()
rescue
e ->
Logger.error("""
LSP Exited.
#{message}
#{Exception.format(:error, e, __STACKTRACE__)}
""")
reraise e, __STACKTRACE__
end
defp dump!(%struct{} = structure) do
{:ok, output} = Schematic.dump(struct.schematic(), structure)
output
end
@doc false
def system_continue(parent, deb, state) do
loop(state, parent, deb)
end
@doc false
def system_terminate(reason, _parent, _deb, _chs) do
exit(reason)
end
@doc false
def system_get_state(state) do
{:ok, state}
end
@doc false
def system_replace_state(state_fun, state) do
new_state = state_fun.(state)
{:ok, new_state, new_state}
end
@doc """
Send a `window/logMessage` notification to the client.
## Usage
```elixir
GenLSP.log(lsp, :warning, "Failed to compiled!")
```
"""
@spec log(GenLSP.LSP.t(), :error | :warning | :info | :log, String.t()) :: :ok
def log(lsp, level, message) when level in [:error, :warning, :info, :log] do
GenLSP.notify(lsp, %GenLSP.Notifications.WindowLogMessage{
params: %GenLSP.Structures.LogMessageParams{
type: apply(GenLSP.Enumerations.MessageType, level, []),
message: message
}
})
end
end
