New (incomplete and x64 only) LSP client plugin

Ekopalypse

I’m starting to question whether using a WebView for the hover part is really beneficial.
It complicates more than one could, probably, benefit from and it slows down the startup of npp considerably.
I know I could start it “lazily” by initializing everything the first time I use it.
But running 6 additional processes … hmmm … and what are they doing in the background? Links can also be opened via Scintilla … the styling options are of course limited but is that really needed.
And there are certainly some servers that don’t support Markdown at all …
yes pylsp I am looking at you for example.
What do you think, does it make sense to use a WebView?

PeterJones

@Ekopalypse ,

I recently found perlnavigator, which is a Perl LSP server that has with a pre-built Windows executable, and I can actually unzip it at work (where I was never able to get Perl::LanguageServer to install properly at work, so I never bothered at home). And I confirmed it defaults to STDIO mode for communication, so it should be compatible with your new plugin. (And it’s dead-simple to install: just unzip the perlnavigator-win-x86_64.zip and put the perlnavigator.exe in your path or a known location; --stdio seems to be the only command line argument needed)

So I downloaded your NppLspClient v0.0.26-alpha and installed it in a v8.6.2 portable (since the alpha download pages showed they need < v8.6.3).

Initial problem: when it creates NppLspConfig.toml, I get an error in the auto-generated config file:

If I add [lspservers] as line 1, that error goes away. But I would hope the auto-created config would not have syntax errors. :-)

Second, I was surprised to not see syntax highlighting in the config file. Why did you pick a config language that Notepad++ doesn’t recognize out-of-the-box? ;-) Do you prefer a UDL (like the one listed in the UDL Collection)? Or do you just assign .toml to the INI builtin language?

----

But, after a few false starts (which were me having mistakes in the config file), I was able to get it working (for the first level of “it works”)

[lspservers.perl]
mode = "io"
executable = 'c:\\usr\\local\\bin\\perlnavigator.exe'
args = '--stdio'
auto_start_server = false

And I can see a function in the “Symbols”, and clicking in the Symbols list will take me to the definition of a function. But if I add a new function, or insert lines before a function, it doesn’t refresh. Is there a way to get it to refresh automatically (at least when the source is saved)? Or is that a limitation of the current implementation of the Client? Or is the PerlNavigator server not responding to your client’s request for a refresh?

Even though clicking in the Symbols panel will allow me to go to the function, “Goto declaration/implementation/definition” doesn’t seem to do anything for me. I don’t know whether it’s just there need to be more options sent to the perlnavigator server somehow. (its main page seems to show some LspClients in other editors have settings that they can pass to the server; is there something like that in NppLspClient?)

Is there something specific at >= v8.6.3 that causes it to “not work”, or have you just not upgraded beyond that yet, so haven’t tried? (I tried installing it in my daily 8.6.4, and it didn’t crash and would show my function, but since I haven’t seen many features work, I don’t know if there’s something that I haven’t tried that causes a crash, or what.)

Anyway, sorry for the rambling. I still don’t have a lot of (really, any) experience with LSP. But I’m really hoping I can eventually figure out how to make it useful for my perl code.

Ekopalypse

@PeterJones

First of all, many thanks for the testing and the detailed experience report.

But I would hope the auto-created config would not have syntax errors. :-)

The error comes from the TOML linter. From the plugin’s point of view, an initial configuration is not usable because it does not contain an lspserver configuration. I am currently not sure if I can simply overwrite the error message, but a check for this specific text and then a more meaningful message should always be possible.

Why did you pick a config language that Notepad++ doesn’t recognize out-of-the-box?

I wanted to have a configuration file format that could use comments and that was already supported by V at the time, hence my choice of toml. I am currently using a very experimental toml lexer, but previously I used the udl lexer.

… at least when the source is saved

That should already work, symbols are queried every time you save a document.
Can you give a simple test case?

“Goto declaration/implementation/definition” doesn’t seem to do anything for me

It could be that this is not supported by the server or you have discovered a bug.
Right now I’m just returning from the function, maybe I should log something in the console window to alert the user that the current operation is not supported by the server.

Is there something specific at >= v8.6.3 that causes it to “not work”,

Yes, certain events have been disabled that the plugin requires.
See here for more information) for more information. Everything seems to work with 8.6.5 so far.

By the way, if you enable debugging via the configuration, the communication between the lsp client and the servers is logged which can be helpful for root cause analysis.
The log is created in the plugin\config\npplspclient directory with the respective Npp process ID.
Caution, the respective log is also deleted when Npp is closed.

LSP communication currently recognizes 3 message types that can be sent by the client or any server.
Requests, responses and notifications.
Each request must be sent with a unique ID and answered by the other side with a response and this ID.
Notifications are only received and do not have this ID.

PeterJones

@Ekopalypse ,

because it does not contain an lspserver configuration

Ah, okay. I can confirm, I can remove my dummy [lspservers] section once I have [lspservers.perl], and it won’t flag that error.

hence my choice of toml.

My question was actually meant as a “tongue-in-cheek” joke. Sorry if that didn’t translate. TOML is a standards-based similar to INI, so I can definitely see why one would want to use it (and why it would be a pre-implemented for your language of choice, as opposed to trying to implement an INI library, given the multitude of INI variations)

I am currently using a very experimental toml lexer, but previously I used the udl lexer.

Okay, I’ll probably snag the UDL, then.

That should already work, symbols are queried every time you save a document.
Can you give a simple test case?

Apparently, I cannot, because the same experiments I tried yesterday are working today.

It could be that this is not supported by the server or you have discovered a bug.

PerlNavigator claims to support “Go to definition”, whether it needs to go elsewhere in the same file or into a used module.

Right now I’m just returning from the function, maybe I should log something in the console window to alert the user that the current operation is not supported by the server.

… or maybe the Diagnostics window (unless that has a different meaning… I don’t know what all the specifics are for LSP yet, and what is expected to go where4)

I selected the name of a function that comes from an external module, and then started the LSP server and did Goto definition, and nothing happened. I then grabbed the log at that point:

2024-04-03 06:18:31.141685 [INFO][ThreadId(1)] -   process arguments provided are: "--stdio" !!
2024-04-03 06:18:31.540531 [INFO][ThreadId(1)] -   start_server perl started.
2024-04-03 06:18:31.540748 [INFO][ThreadId(1)] - {"id":0,"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{"general":{"positionEncodings":["utf-8"]},"textDocument":{"codeAction":{"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["quickfix"]}}},"completion":{"completionItem":{"commitCharactersSupport":false,"deprecatedSupport":false,"documentationFormat":["plaintext"],"insertReplaceSupport":false,"preselectSupport":false,"snippetSupport":false},"completionItemKind":{},"dynamicRegistration":false,"insertTextMode":1},"formatting":{"dynamicRegistration":false},"hover":{"contentFormat":["plaintext","markdown"],"dynamicRegistration":false},"publishDiagnostics":{"codeDescriptionSupport":false,"dataSupport":false,"relatedInformation":true,"versionSupport":false},"rangeFormatting":{"dynamicRegistration":false},"signatureHelp":{"contextSupport":false,"dynamicRegistration":false,"signatureInformation":{"activeParameterSupport":false,"documentationFormat":["plaintext"],"parameterInformation":{"labelOffsetSupport":false}}},"synchronization":{"didSave":true,"dynamicRegistration":false,"willSave":true,"willSaveWaitUntil":false}},"window":{"showDocument":{"support":true},"showMessage":{"messageActionItem":{"additionalPropertiesSupport":true}},"workDoneProgress":true},"workspace":{"executeCommand":{"dynamicRegistration":true},"workspaceFolders":true}},"clientInfo":{"name":"","version":"-alpha"},"processId":27088,"rootUri":"file:///C:/usr/local/apps/npp/npp862.ps3","workspaceFolders":[{"name":"npp862.ps3","uri":"file:///C:/usr/local/apps/npp/npp862.ps3"}]}}
2024-04-03 06:18:31.541009 [INFO][ThreadId(10)] - <<< {"id":0,"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{"general":{"positionEncodings":["utf-8"]},"textDocument":{"codeAction":{"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["quickfix"]}}},"completion":{"completionItem":{"commitCharactersSupport":false,"deprecatedSupport":false,"documentationFormat":["plaintext"],"insertReplaceSupport":false,"preselectSupport":false,"snippetSupport":false},"completionItemKind":{},"dynamicRegistration":false,"insertTextMode":1},"formatting":{"dynamicRegistration":false},"hover":{"contentFormat":["plaintext","markdown"],"dynamicRegistration":false},"publishDiagnostics":{"codeDescriptionSupport":false,"dataSupport":false,"relatedInformation":true,"versionSupport":false},"rangeFormatting":{"dynamicRegistration":false},"signatureHelp":{"contextSupport":false,"dynamicRegistration":false,"signatureInformation":{"activeParameterSupport":false,"documentationFormat":["plaintext"],"parameterInformation":{"labelOffsetSupport":false}}},"synchronization":{"didSave":true,"dynamicRegistration":false,"willSave":true,"willSaveWaitUntil":false}},"window":{"showDocument":{"support":true},"showMessage":{"messageActionItem":{"additionalPropertiesSupport":true}},"workDoneProgress":true},"workspace":{"executeCommand":{"dynamicRegistration":true},"workspaceFolders":true}},"clientInfo":{"name":"","version":"-alpha"},"processId":27088,"rootUri":"file:///C:/usr/local/apps/npp/npp862.ps3","workspaceFolders":[{"name":"npp862.ps3","uri":"file:///C:/usr/local/apps/npp/npp862.ps3"}]}}
2024-04-03 06:18:31.541807 [INFO][ThreadId(1)] - Storing on_buffer_activated request for C:\usr\local\apps\npp\npp862.ps3\lsp-test.pl [2058226367408]
2024-04-03 06:18:31.724127 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":0,"result":{"capabilities":{"textDocumentSync":2,"completionProvider":{"resolveProvider":true,"triggerCharacters":["$","@","%","-",">",":"]},"definitionProvider":true,"documentSymbolProvider":true,"workspaceSymbolProvider":true,"hoverProvider":true,"documentFormattingProvider":true,"documentRangeFormattingProvider":true,"signatureHelpProvider":{"triggerCharacters":["(",",",")"]},"workspace":{"workspaceFolders":{"supported":true}}}}}
2024-04-03 06:18:31.724411 [INFO][ThreadId(1)] - ServerCapabilities { position_encoding: None, text_document_sync: Some(Kind(Incremental)), selection_range_provider: None, hover_provider: Some(Simple(true)), completion_provider: Some(CompletionOptions { resolve_provider: Some(true), trigger_characters: Some(["$", "@", "%", "-", ">", ":"]), all_commit_characters: None, work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None }, completion_item: None }), signature_help_provider: Some(SignatureHelpOptions { trigger_characters: Some(["(", ",", ")"]), retrigger_characters: None, work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None } }), definition_provider: Some(Left(true)), type_definition_provider: None, implementation_provider: None, references_provider: None, document_highlight_provider: None, document_symbol_provider: Some(Left(true)), workspace_symbol_provider: Some(Left(true)), code_action_provider: None, code_lens_provider: None, document_formatting_provider: Some(Left(true)), document_range_formatting_provider: Some(Left(true)), document_on_type_formatting_provider: None, rename_provider: None, document_link_provider: None, color_provider: None, folding_range_provider: None, declaration_provider: None, execute_command_provider: None, workspace: Some(WorkspaceServerCapabilities { workspace_folders: Some(WorkspaceFoldersServerCapabilities { supported: Some(true), change_notifications: None }), file_operations: None }), call_hierarchy_provider: None, semantic_tokens_provider: None, moniker_provider: None, linked_editing_range_provider: None, inline_value_provider: None, inlay_hint_provider: None, diagnostic_provider: None, experimental: None }
2024-04-03 06:18:31.724480 [INFO][ThreadId(1)] - Handling stored file C:\usr\local\apps\npp\npp862.ps3\lsp-test.pl [2058226367408]
2024-04-03 06:18:31.724488 [INFO][ThreadId(10)] - <<< {"jsonrpc":"2.0","method":"initialized","params":{}}
2024-04-03 06:18:31.724572 [INFO][ThreadId(10)] - <<< {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"languageId":"perl","text":"#!/usr/bin/perl\r\n\r\nuse warnings;\r\nuse strict;\r\nuse lib '.';\r\nuse myModule;\r\n\r\nprint \"Hello World\\n\";\r\n\r\n=head2 ThisHereFunction\r\n\r\nPOD description\r\n\r\n=cut\r\n\r\n# Comment before sub\r\nsub ThisHereFunction {\r\n    # comment as first line of sub\r\n    my ($x,$y,$z) = @_;\r\n    return 0;\r\n}\r\n\r\nsub second { 1; }\r\n\r\nmy $t = ThisHereFunction();\r\n\r\nmy $f = myModule::func();\r\n","uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl","version":0}}}
2024-04-03 06:18:31.724604 [INFO][ThreadId(10)] - <<< {"id":1,"jsonrpc":"2.0","method":"textDocument/documentSymbol","params":{"textDocument":{"uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl"}}}
2024-04-03 06:18:31.726886 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":0,"method":"workspace/workspaceFolders"}
2024-04-03 06:18:31.726966 [ERROR][ThreadId(1)] - Unhandled request 
{
  "id": 0,
  "jsonrpc": "2.0",
  "method": "workspace/workspaceFolders"
}
2024-04-03 06:18:31.727015 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":1,"method":"workspace/workspaceFolders"}
2024-04-03 06:18:31.727046 [ERROR][ThreadId(1)] - Unhandled request 
{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "workspace/workspaceFolders"
}
2024-04-03 06:18:31.780060 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":1,"result":[{"kind":12,"location":{"range":{"start":{"line":16,"character":0},"end":{"line":20,"character":100}},"uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl"},"name":"ThisHereFunction"},{"kind":12,"location":{"range":{"start":{"line":22,"character":0},"end":{"line":22,"character":100}},"uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl"},"name":"second"}]}
2024-04-03 06:18:32.738187 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":2,"method":"workspace/workspaceFolders"}
2024-04-03 06:18:32.738469 [ERROR][ThreadId(1)] - Unhandled request 
{
  "id": 2,
  "jsonrpc": "2.0",
  "method": "workspace/workspaceFolders"
}
2024-04-03 06:18:58.116894 [INFO][ThreadId(10)] - <<< {"id":2,"jsonrpc":"2.0","method":"textDocument/definition","params":{"position":{"character":8,"line":26},"textDocument":{"uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl"}}}
2024-04-03 06:18:58.117730 [INFO][ThreadId(9)] - >>>  {"jsonrpc":"2.0","id":2,"result":null}

It looks like the server replies with "result":null …

stopping the server, clearing out the log, and simplifying the code to

#!/usr/bin/perl

use warnings;
use strict;
use lib '.';
use myModule;

print "Hello World\n";

sub ThisHereFunction {
    my ($x,$y,$z) = @_;
    return 0;
}

my $t = ThisHereFunction();

… with my cursor in the middle of the sH from ThisHereFunction() on the last line

Then I start the LSP server again, and do Goto definition, and even though the definition is just a few lines above in the same file, it doesn’t go anywhere, and the pair of commands in the log shows:

2024-04-03 06:36:09.405503 [INFO][ThreadId(13)] - <<< {"id":3,"jsonrpc":"2.0","method":"textDocument/definition","params":{"position":{"character":12,"line":14},"textDocument":{"uri":"file:///C:/usr/local/apps/npp/npp862.ps3/lsp-test.pl"}}}
2024-04-03 06:36:09.406479 [INFO][ThreadId(12)] - >>>  {"jsonrpc":"2.0","id":3,"result":null}

So it’s still returning null. :-(

I am hoping that @Michael-Vincent , who knows Perl, and has tried your plugin earlier in this conversation with other languages, and seems to understand how it should behave, will be able to try some experiments with Perl and the PerlNavigator, so that he can supply differences of behavior between what he’s already seen with other languages and what he sees in Perl … or so that he can tell me what I’m doing wrong with my what-I-thought-were-simple Perl experiments. It might just be that I’m not doing things in the right order, or not using the right steps to activate features.

Everything seems to work with 8.6.5 so far.

Oh, good. I was thinking of updating to that version for my daily use anyway, since it seems to be stable. But it will be nice to be able to play with this plugin without having to jump to a different N++ instance.

Michael Vincent

@PeterJones said in New (incomplete and x64 only) LSP client plugin:

I am hoping that @Michael-Vincent , who knows Perl, and has tried your plugin earlier in this conversation with other languages,

I should note: Notepad++ 8.6.5 64-bit with NppLspClient v.0.0.26-alpha

Trying with Perl setup as @PeterJones , I get the same results - it seems like it’s not working.

With this Python setup:

[lspservers.python]
mode = "io"
executable = 'c:\Users\VinsWorldcom\AppData\Roaming\Python\Scripts\pylsp.exe'
args = '--check-parent-process --log-file c:\Users\VinsWorldcom\tmp\pylsp.log -vvv'
auto_start_server = false

and this simple Python script:

#!python

import os
import sys

def myadd(n1, n2):
    return n1 + n2
    
t = myadd(1, 2)

Putting my caret between the y and a of the myadd() call on the last line and selecting Plugins => NppLspClient => Goto definition, it moves my caret to just before the m in the def myadd( ... line - as expected. Log shows:

2024-04-03 10:44:09.702659 [INFO][ThreadId(4)] - <<< {"id":75,"jsonrpc":"2.0","method":"textDocument/definition","params":{"position":{"character":6,"line":8},"textDocument":{"uri":"file:///C:/Users/VinsWorldcom/tmp/crapps/test.py"}}}
2024-04-03 10:44:09.705734 [INFO][ThreadId(3)] - >>>  {"jsonrpc":"2.0","id":75,"result":[{"uri":"file:\/\/\/c:\/Users\/VinsWorldcom\/tmp\/crapps\/test.py","range":{"start":{"line":5,"character":4},"end":{"line":5,"character":9}}}]}

Cheers.

Ekopalypse

@PeterJones said in New (incomplete and x64 only) LSP client plugin:

{“jsonrpc”:“2.0”,“id”:2,“result”:null}

That’s a valid response from the server if it can’t specify the location … but … why can’t it!

What version of Perl are you using?

Maybe it’s related to the unhandled “workspace/workspaceFolders” request that the NppLspClient plugin seems to ignore … again … why? … dooh - typo …
I must have been hungry to wait for a “workspace/wokspaceFolders” request …

… or maybe the Diagnostics window

No, this is reserved for exclusively handle diagnostics.
Perhaps a temporary (3-5 sec) pop-up window that overlays the status bar area and states that this is not supported by the server.

PeterJones

@Ekopalypse said in New (incomplete and x64 only) LSP client plugin:

That’s a valid response from the server if it can’t specify the location … but … why can’t it!
What version of Perl are you using?

Strawberry Perl v5.38.0 – and it’s in my path, so PerlNavigator should be able to find it without options being passed from the client to the server.

Maybe it’s related to the unhandled “workspace/workspaceFolders” request that the NppLspClient plugin seems to ignore … again … why? … dooh - typo …
I must have been hungry to wait for a “workspace/wokspaceFolders” request …

:-)

No, this is reserved for exclusively handle diagnostics.

Ah, that’s fine.

Perhaps a temporary (3-5 sec) pop-up window that overlays the status bar area and states that this is not supported by the server.

I think Console is fine, and probably less work for you than a popup.

Ekopalypse

@PeterJones

Looks like it is caused by the unhandled request.

and now the server responded, for the goto definition request, with

{
    "id": 33,
    "jsonrpc": "2.0",
    "result": [
        {
            "range": {
                "end": {
                    "character": 500,
                    "line": 9
                },
                "start": {
                    "character": 0,
                    "line": 9
                }
            },
            "uri": "file:///D:/scripts/perl/tests/main.pl"
        }
    ]
}

But the end character 500 is not correct.
The formatting does not seem to work either.
Renaming is not supported by the server.

I will prepare another alpha version tomorrow and make it available.

PeterJones

@Ekopalypse said in New (incomplete and x64 only) LSP client plugin:

I will prepare another alpha version tomorrow and make it available.

Great! Looking forward to it.

Ekopalypse

@PeterJones

I’ve opened an issue that I wanted to wait for before releasing a new version.