Module lsp 

External Python language server over stdio (pyright-family).

pite-editor never embeds a server: it spawns pyright-langserver --stdio (or PITE_LSP_CMD), syncs the code pane with didOpen/didChange, and surfaces completion, hover, signature help, and publishDiagnostics. The shipped pite.pyi stubs go on the server’s path so import pite resolves. No DAP, no bundled binary.

The protocol core is transport-agnostic: Bridge speaks JSON-RPC over any RpcTransport. Production uses StdioTransport (real child stdio); tests drive the same Bridge with a mock server.

Structs

Bridge

Protocol state above a transport: request ids, pending kinds, typed results, and per-document diagnostics.

ChildGuard

Owns the child process; killing on drop so no server outlives the editor.

CompletionItem

One completion candidate.

Diagnostic

One server diagnostic (0-based line, protocol severity 1=error..4=hint).

FramingReader

Parse Content-Length-framed messages from any buffered reader.

LspClient

A ready-to-use server connection for one editor session.

StdioTransport

Real child-stdio transport: writes go straight to the server’s stdin, a reader thread forwards framed replies to a channel.

Enums

LspOutcome

Starter outcome delivered to the UI thread.

Constants

ENV_CMD_OVERRIDE

Env override for the server command (a binary name or path).

PINNED_PYRIGHT

Documented prerequisite; keep in sync with docs/lsp.md.

SERVER_ARGS

Args for the default command.

SERVER_CMD

Default server command; ENV_CMD_OVERRIDE replaces it.

STUBS_FILE

Shipped stubs file; its parent dir goes on the server’s extraPaths.

Traits

RpcTransport

Byte transport for JSON-RPC values. Production speaks over child stdio; tests substitute a mock server speaking the same messages.

Functions

byte_offset_of_char

Byte offset of a char offset (egui cursors count chars).

completion_request

configuration_response

Answer a server workspace/configuration pull. The answer is the requested SECTION VALUE (result[0] pairs with items[0]): for section "python" that is the {"analysis": ...} object itself — NOT wrapped in another "python" layer, which the server would read as a section with no analysis and silently drop (that exact shape starved import pite of its stubs). Anything else gets an empty object (defaults hold).

did_change_configuration

extraPaths + basic type-checking mode so the shipped stubs resolve.

did_change_notification

did_open_notification

encode_message

Frame a JSON-RPC value with Content-Length headers.

find_stubs_dir

Walk up from start looking for python/pite/pite.pyi (or a bare pite.pyi); return the dir containing it — what goes on extraPaths so import pite resolves to the shipped stubs.

hover_request

initialize_request

initialize carrying the project root. Settings travel separately via didChangeConfiguration (and workspace/configuration answers).

initialized_notification

line_start_byte

Byte offset of the start of 1-based line (clamped to end of text).

materialized_stubs_dir

Versioned scratch dir for the embedded stubs; the last resort behind find_stubs_dir, so a checkout’s own stubs always win.

missing_server_message

Loud message when no server is installed. Editing continues without LSP.

offset_to_position

(line, character) for an LSP position. Lines are 0-based; characters count UTF-16 code units per the protocol.

parse_completion_items

Parse a completion result (array or {items}; null means no candidates).

parse_hover

Parse a hover result into plain text (markdown fenced content included).

parse_publish_diagnostics

Parse publishDiagnostics params into diagnostics (empty when clean).

parse_signature_help

Parse signature help into one line per overload.

parse_version

First major.minor.patch in free-form --version output.

path_to_uri

Best-effort file:// URI for a path. Falls back to the raw path text when the current dir is unknown; servers only need it as a document key.

probe_server_version

Best-effort version probe: (version, warning). Never fails; a missing binary surfaces later at spawn with the loud message.

signature_request

spawn_lsp

Spawn the server in the background and run the initialize handshake there (cold starts take seconds). The receiver gets exactly one outcome; a missing binary fails fast and loudly, never silently.

uri_from_path_text

Build a file:// URI from an absolute path string, on any platform. Windows needs file:///D:/dir/file.py — forward slashes and a leading slash before the drive letter. Emitting file://D:\dir\file.py (naive concatenation) makes the server report the directory as nonexistent, so the conversion is explicit rather than string-pasted.

version_at_least

Numeric triple comparison against the pin.

word_end_after

End byte offset of the identifier starting at byte_offset (letters, digits, _); accepting mid-word replaces up to here.

word_start_before

Start byte offset of the identifier ending at byte_offset (letters, digits, _); completion replaces from here.

write_stubs_to

Write the embedded stubs into dir, skipping files that already match. Returns the dir for extraPaths.