Tree-sitter Parser for Seed7

A Tree-sitter parser for the Seed7 programming language, enabling syntax highlighting, code folding, and parsing for Seed7 code in editors like Neovim.

Features

• Syntax Support:

  • Include directives: $ include "file";
  • Constants: const proc: name is func ...
  • Functions: func local ... begin ... end func
  • Variables: var string: name is "value";
  • Control structures: if, else, elsif, for, repeat, while, case (with when and set expressions)
  • Expressions: Identifiers, strings, integers, function calls, concatenation (<&), comparisons (=, <>, <, >, <=, >=), assignments (:=), arithmetic (+, -, *, /), set literals ({}), ranges (..), set unions (|)
  • Types: proc, string, integer
  • Comments: # ..., (* ... *), {* ... *}

• Editor Integration: Syntax highlighting for Neovim via queries/seed7/highlights.scm.

Installation

Prerequisites

• Neovim (version 0.9.0 or later recommended).
• Tree-sitter CLI: Install via npm install -g tree-sitter-cli.
• Node.js and npm for Tree-sitter CLI.
• nvim-treesitter plugin installed in Neovim.
• Git for cloning the repository.

Manual Installation

Since this parser is not yet included in nvim-treesitter, follow these steps to install it manually:

1. Clone the Repository:

   git clone https://github.com/aliqyan-21/tree-sitter-seed7.git ~/.local/share/nvim/site/pack/parser/start/tree-sitter-seed7
   cd ~/.local/share/nvim/site/pack/parser/start/tree-sitter-seed7

2. Generate the Parser:

   tree-sitter generate

3. Configure Neovim for the Parser: Add the following to your Neovim configuration (e.g., ~/.config/nvim/init.lua or a file in ~/.config/nvim/lua/):

   local parser_config = require("nvim-treesitter.parsers").get_parser_configs()
   parser_config.seed7 = {
     install_info = {
       url = "~/.local/share/nvim/site/pack/parser/start/tree-sitter-seed7", -- Local path to the parser
       files = { "src/parser.c" },
       branch = "main",
       generate_requires_npm = false, -- Pre-generated parser.c included
     },
     filetype = "sd7",
   }

4. Set Up Filetype Detection: Since Vim/Neovim does not natively recognize the sd7 filetype, add the following to ~/.config/nvim/ftdetect/seed7.vim to associate .sd7 files with the seed7 filetype:

   vim.cmd [[autocmd BufRead,BufNewFile *.sd7 set filetype=seed7]]

   For vim:

   autocmd BufRead,BufNewFile *.sd7 setfiletype seed7

5. Copy Highlight Queries: Copy the highlighting queries to Neovim’s query directory:

   mkdir -p ~/.local/share/nvim/site/queries/seed7
   cp ~/.local/share/nvim/site/pack/parser/start/tree-sitter-seed7/queries/seed7.scm ~/.local/share/nvim/site/queries/seed7/highlights.scm

6. Install the Parser in Neovim: Open Neovim and run:

   :TSInstall seed7

   This compiles and installs the parser for use with nvim-treesitter.

7. Verify Installation: Open a Seed7 file:

   nvim ~/.local/share/nvim/site/pack/parser/start/tree-sitter-seed7/test_case.sd7

   Check syntax highlighting with:

   :TSHighlightCapturesUnderCursor

Alternative: Using a Package Manager

If you use a Neovim package manager like packer.nvim, you can add the parser as a custom repository:

use {
  'aliqyan-21/tree-sitter-seed7',
  config = function()
    local parser_config = require("nvim-treesitter.parsers").get_parser_configs()
    parser_config.seed7 = {
      install_info = {
        url = "~/.local/share/nvim/site/pack/packer/start/tree-sitter-seed7", -- Adjust path based on your package manager
        files = { "src/parser.c" },
        branch = "main",
        generate_requires_npm = false,
      },
      filetype = "sd7",
    }
  end
}

After adding, run :PackerSync (or equivalent) and :TSInstall seed7.

Testing

Test the parser with provided Seed7 test files:

tree-sitter parse test_case.sd7

Verify output shows no ERROR nodes. Open in Neovim to confirm highlighting:

nvim test_case.sd7

Limitations

The parser is under active development and has the following limitations:

• Unsupported types: float, char, boolean.
• Unsupported operators: div, and, or, not.
• Missing features:
  • Unary operators.
  • Subscripts.
  • Type declarations.
  • Function parameters (e.g., game(in integer: min, in integer: max) is func).
  • Constant declarations (treated as identifiers).
  • Arrays.
• See Issues for planned enhancements.

Contributions to address these limitations are highly encouraged.

Contributing

We welcome contributions to improve the parser’s stability and feature set. To contribute:

1. Fork the repository: https://github.com/aliqyan-21/tree-sitter-seed7.
2. Create a feature branch: git checkout -b feature-name.
3. Modify grammar.js, add test files, or update queries/seed7.scm.
4. Test changes:

   tree-sitter generate
   tree-sitter parse test_*.sd7

5. Submit a pull request with a clear description of changes.

Refer to the Seed7 Manual for syntax accuracy.

License

MIT License

Acknowledgements

• Thomas Mertes and Seed7 Community for developing Seed7.
• Tree-sitter and nvim-treesitter for parsing and highlighting infrastructure.