Pseudocode-i18n for Thonny

Use multilingual .pseudo and .algo files in Thonny 5 with the same parser, diagnostics, completions, i18n snippets and navigation as the rest of the pseudocode-i18n ecosystem.

Current version: 0.9.1.

0.9.1 — native Thonny workflow on top of the shared LSP

Version 0.9.1 consolidates the Thonny 5 integration and documents the final 0.9 behavior:

• a dedicated Pseudocode root menu is translated according to the Thonny UI language, independently from the language of the Pseudocode source file;
• .pseudo and .algo use the same core parser, linter, type system, snippets, hover help and module resolution as VS Code;
• diagnostics underline the real offending range, multiple independent errors can be visible at once, and a diagnostic under the pointer takes priority over generic keyword help;
• pointer hover is LSP-backed, localized and exhaustive; Markdown fence markers are removed before display in Tk tooltips;
• completion keeps the canonical multilingual snippets, signature help uses Thonny calltips, and Ctrl+click navigates to definitions;
• formatting, conversion Pseudocode ↔ Python, Mermaid/SVG/PNG flowchart actions, navigation and server restart are grouped in the Pseudocode menu;
• the dockable Pseudocode view separates Diagnostics, Informations (plugin/developer information), contextual Aide, and Algorigramme;
• F5 / Run current script / the green triangle on .pseudo / .algo routes to the same !pseudo <file> CLI path used manually in the Shell, preserving localized Pseudocode errors and original source lines instead of leaking Python backend exceptions;
• normal .py execution remains untouched;
• yarn setup removes the obsolete thonnycontrib.backend.pseudocode_i18n development hook and stale bytecode from older 0.9 checkouts;
• Python is not bundled: installing thonny-pseudocode-i18n lets pip resolve the shared core, LSP and Pygments dependencies normally.

The plugin stays a thin Thonny adapter; language intelligence remains centralized in the core/LSP so future IDE integrations receive the same behavior.

What the plugin adds

thonny-pseudocode-i18n is deliberately a thin editor adapter. It does not contain a second parser, semantic analyser or snippet catalogue.

• .pseudo and .algo are registered as one Thonny language: pseudocode;
• the plugin starts the shared pseudo-lsp server over stdio with a small JSON-RPC client;
• diagnostics returned by the server are underlined in the editor and exposed from the dedicated Pseudocode menu;
• Ctrl+Space reuses Thonny's completion popup and requests language-aware completions from pseudo-lsp;
• localized structural snippets are proposed according to the normal pseudocode-i18n language resolution rules;
• signature help reuses Thonny's existing calltip UI;
• pointer hover waits briefly (450 ms) and then shows the same pedagogical LSP documentation as other IDEs, including localized section labels and every accepted syntax synonym;
• Ctrl+click on a symbol uses textDocument/definition and opens its definition;
• syntax coloring is driven by pygments-lexer-pseudocode-i18n and uses Thonny's active syntax-theme tags;
• a localized root Pseudocode menu organizes run/analyze/format/language, conversion, flowcharts, navigation, information, diagnostics and language-server restart; its UI language follows Thonny, independently from the source pseudocode language;
• the dockable Pseudocode view separates diagnostics, static plugin/developer information, contextual help and Mermaid flowchart output;
• project-aware diagnostics resolve math, random and existing local .pseudo / .algo modules from the current document/project path, while unknown modules receive a squiggle alongside other diagnostics;
• universal alea() and entalea(a, b) are available through the shared completion/hover/signature-help vocabulary.
• normal Python editing remains handled by Thonny exactly as before.

For example, in a French file:

# language: fr

Fonction carré(x: réel) -> réel:
    Renvoyer x^2
Fin

Afficher carré(3)

press Ctrl+Space while editing to ask pseudo-lsp for completions. The language server resolves the document as French and offers the French templates from pseudocode-i18n.

!!! note "Snippets in Thonny 5" The adapter deliberately advertises snippetSupport = false. pseudo-lsp therefore converts canonical LSP snippets to safe plain-text templates before insertion. The same canonical snippet remains a real tabstop snippet in clients such as VS Code or Neovim that advertise snippet support.

Why there is a small LSP client in this plugin

Thonny 5 stable does not yet expose the generic external-language-server proxy API present on the development branch for the next major Thonny version. This plugin therefore owns only the transport/adaptation layer needed by Thonny 5: JSON-RPC framing, document synchronization and mapping responses to Thonny UI components.

The actual language intelligence remains in pseudocode-i18n and pseudocode-i18n-languageserver. When a future stable Thonny exposes a generic LSP proxy, this adapter can be simplified without changing the language or server.

Installation

The administrator installs one package:

python -m pip install 'thonny-pseudocode-i18n>=0.9.1,<0.10'

The package declares Thonny 5, pseudocode-i18n, pseudocode-i18n-languageserver and pygments-lexer-pseudocode-i18n as normal PyPI dependencies, so pip resolves them. Python is not embedded or downloaded by the plugin.

Installation for development

Keep the ecosystem repositories as siblings when developing locally:

pseudocode-i18n/
pygments-lexer-pseudocode-i18n/
pseudocode-i18n-languageserver/
thonny-pseudocode-i18n/

Then:

yarn setup
yarn bfc

yarn setup prefers the sibling 0.9.x checkouts and installs this plugin editable. Restart Thonny after installation so its plugin loader discovers thonnycontrib.pseudocode_i18n.

First manual test

Create test.algo:

# language: fr

Fonction double(x: entier) -> entier:
    Renvoyer x * 2
Fin

Afficher double(21)

Open it in Thonny. Then verify:

1. the file is recognized as Pseudocode and colored;
2. introduce an undefined name and check that it is underlined, then use Pseudocode → Diagnostics;
3. press Ctrl+Space and verify localized completions/templates;
4. Ctrl+click double in the call to jump to its definition;
5. use Pseudocode → Format or Ctrl+Shift+I;
6. use Pseudocode → Information and Pseudocode → Navigation → Rename symbol….

Architecture

Thonny 5
  │
  └── thonny-pseudocode-i18n
        ├── file type adapter (.pseudo / .algo)
        ├── thin JSON-RPC/LSP stdio client
        ├── Pygments coloring adapter
        └── Thonny UI adapters
              │
              ▼
          pseudo-lsp
              │
              ▼
        pseudocode-i18n

The language definitions, parser, formatter, diagnostics, semantic index, language detection and snippets stay in pseudocode-i18n. The LSP protocol stays in pseudocode-i18n-languageserver.

Development registration in Thonny 5

yarn setup installs the Python package and also exposes the checkout under Thonny 5's dedicated thonnycontrib plugin directory. Restart Thonny completely after running setup. On Linux, plugin loading can be diagnosed from ~/.config/Thonny/frontend.log.

Development

Useful commands:

yarn setup
yarn test
yarn lint
yarn dev
yarn dev:lan
yarn bfc
yarn zip

package.json is the source of truth for the project version.

License

GNU General Public License version 3 or later (GPL-3.0-or-later).

Run with Thonny

For .pseudo and .algo files, Thonny's normal Run current script, F5 and green-triangle toolbar button are routed to the same !pseudo <file> CLI execution that can be typed manually in the Shell. This preserves localized Pseudocode diagnostics, source lines and interactive input instead of exposing Python/Thonny backend exceptions. Python files continue to use Thonny's ordinary execution handler unchanged.

During development, yarn setup also removes the obsolete preprocessor hook thonnycontrib.backend.pseudocode_i18n left by older checkouts. This prevents Thonny from discovering a stale backend plugin after upgrading.