Picat Plugin for IntelliJ IDEA

This plugin provides support for the Picat programming language in IntelliJ IDEA.

    Support for the Picat programming language in IntelliJ IDEA.

    <p>Picat is a multi-paradigm programming language that integrates logic-based and function-based programming with constraint solving capabilities.</p>

    <h3>Features:</h3>
    <ul>
        <li>Syntax highlighting for Picat files (.pi)</li>
        <li>Default color themes for Picat elements (customizable per IDE scheme)</li>
        <li>Code formatting with customizable settings</li>
        <li>Run configuration for Picat programs</li>
        <li>Live templates</li>
        <li>Autocompletion</li>
        <li>Navigate | Symbol for predicates/functions</li>
        <li>Quick Documentation (Ctrl+Q) for symbols</li>
        <li>Navigation Bar breadcrumbs for rules</li>
        <li>Spellchecking limited to comments and string literals</li>
        <li>Code folding</li>
        <li>File type recognition</li>
        <li>Custom file icon</li>
        <li>Standard modules recognition: attaches <code>lib</code> directory next to the Picat executable as read-only library; navigate from <code>import</code> to stdlib modules</li>
    </ul>

    <p>This plugin is licensed under the <a href="https://github.com/avrilfanomar/picat-plugin/blob/main/LICENSE">Apache License 2.0</a>.</p>

Features

• Syntax highlighting for Picat files
• Code formatting with customizable settings
• Structure view for Picat files
• Code completion
• Navigation to declarations
• Find usages
• Rename refactoring
• Code folding (rule bodies, multi-clause groups)
• Navigation Bar breadcrumbs
• Quick Documentation (Ctrl+Q)
• Brace matching
• Comment/uncomment actions
• Basic error highlighting

Installation

You can install the plugin from the JetBrains Plugin Repository:

1. Open IntelliJ IDEA
2. Go to File > Settings > Plugins
3. Click on "Marketplace"
4. Search for "Picat"
5. Click "Install"
6. Restart IntelliJ IDEA

Usage

Code Formatting

The plugin includes a powerful code formatter for Picat that can be customized to match your preferred coding style. To format your code:

• Use the keyboard shortcut: Ctrl+Alt+L (Windows/Linux) or Cmd+Alt+L (Mac)
• Or select Code > Reformat Code from the menu

To customize the formatting settings:

1. Go to File > Settings > Editor > Code Style > Picat
2. Adjust the settings to match your preferences
3. Click "Apply" or "OK"

Structure View

The Structure View shows the structure of your Picat file, including predicates, functions, and rules. To open the Structure View:

• Use the keyboard shortcut: Alt+7 (Windows/Linux) or Cmd+7 (Mac)
• Or select View > Tool Windows > Structure from the menu

Live Templates

Common Picat constructs are available as live templates (type the key and press Tab):

• if: if-then block
• ife: if-then-else block
• ifel: if-elseif-else block
• foreach: foreach loop (foreach (X in L) ... end)
• while: while loop (while (Cond) ... end)
• loopw: loop ... while pattern
• try: try-catch block
• tryf: try-catch-finally block

Code Completion

The plugin provides code completion for Picat keywords, built-in predicates, and user-defined predicates and functions. To use code completion:

• Start typing and press Ctrl+Space to see completion suggestions

Navigation

To navigate to a declaration:

• Hold Ctrl (Windows/Linux) or Cmd (Mac) and click on a predicate or function name
• Or place the cursor on a name and press Ctrl+B (Windows/Linux) or Cmd+B (Mac)

Find Usages

To find all usages of a predicate or function:

• Right-click on a predicate or function name and select "Find Usages"
• Or place the cursor on a name and press Alt+F7

Rename Refactoring

To rename a predicate or function:

• Right-click on a predicate or function name and select "Refactor > Rename"
• Or place the cursor on a name and press Shift+F6

Development

• Prerequisites:
  • JDK 21
  • Gradle 9.0 (use the provided wrapper: ./gradlew)
• Build the plugin and run tests: ./gradlew build
• Run tests: ./gradlew test
• Static code analysis (Detekt): ./gradlew detekt
  • Reports are generated in build/reports/detekt/
• Run the IDE with the plugin: ./gradlew runIde

This project uses GrammarKit/JFlex to generate the parser and lexer from grammars:

• Parser is generated from src/main/grammars/Picat.bnf into src/main/gen as com.github.avrilfanomar.picatplugin.language.parser.PicatParser and related PSI/element types.
• Lexer is generated from src/main/grammars/_PicatLexer.flex into src/main/gen as com.github.avrilfanomar.picatplugin.language.parser._PicatLexer.

Important:

• Do not manually modify generated files under src/main/gen, as well as _PicatLexer.flex. Changes to parsing behavior must be done in Picat.bnf, then the sources regenerated.
• Commit regenerated sources as part of your change if you modify the grammar definitions.

Regeneration instructions (local development):

• Gradle tasks for generation are provided and included in the build by default (./gradlew generateParser generateLexer); alternatively, use IDE generators as below.
• Lexer: Use "Run JFlex Generator" on _PicatLexer.flex (Tools | JFlex | Run JFlex Generator) targeting src/main/grammars.
• Parser/PSI: Open the project in IntelliJ IDEA with GrammarKit installed, open Picat.bnf, and use "Generate Parser Code" (Tools | Grammar-Kit | Generate Parser Code) targeting src/main/gen.

The canonical rule: PicatParser is generated from BNF and should not be manually modified.

Contributing

Contributions are welcome! Please follow the Development guidelines above and ensure all tests and Detekt pass before submitting a PR.

License

This plugin is licensed under the Apache License, Version 2.0. See LICENSE for details.

Acknowledgements

• This plugin was developed by Andrii Andriichuk, including parts generated by Jetbrains Junie, Claude AI, OpenAI ChatGPT and Google Jules.