Prettier Pascal Plugin

Intro

Prettier is an opinionated code formatter. It parses your code and reprints it using consistent formatting rules while taking the configured maximum line length into account.

This plugin adds support for the Pascal language to Prettier. I believe that Pascal code deserves the same love and consistency as any modern language.

It uses tree-sitter-pascal to parse Pascal source code and generates Prettier's document structure from the resulting syntax tree.

Input

program HelloWorld;
var
x,y: Integer;

begin
writeln('Hello World!');



if x>y then
begin
writeln('x is greater');
end
else
writeln('y is greater');
end.

Output

program HelloWorld;
  var
    x, y: Integer;

begin
  writeln('Hello World!');

  if x > y then
    begin
      writeln('x is greater');
    end
  else
    writeln('y is greater');
end.

Getting Started

Installation

npm:

npm install --save-dev --save-exact prettier prettier-plugin-pascal

Yarn:

yarn add --dev --exact prettier prettier-plugin-pascal

Usage

npm:

npx prettier --plugin=prettier-plugin-pascal --write "**/*.{pas,pascal,pp}"

Yarn:

yarn exec prettier --plugin=prettier-plugin-pascal --write "**/*.{pas,pascal,pp}"

Supported Extensions

The plugin currently targets these Pascal file extensions:

.pas
.pp
.pascal

Features

The formatter is based on a Tree-sitter Pascal grammar and supports formatting of Pascal constructs including:

• Programs, libraries, and units
• Variable, constant, type, and procedure declarations
• Classes, interfaces, records, properties, and variant records
• Expressions and operators
• Procedure/function implementations
• Control-flow constructs such as if, while, for, repeat, case, and try
• Generic and type-reference syntax
• Pascal and Delphi/FPC-oriented language constructs

Formatting coverage is still evolving, and some advanced Pascal/Delphi/FPC constructs may fall back to a generic printer.

Development

The plugin uses a precompiled tree-sitter-pascal pinned at v0.11.0.9e9f070 release WebAssembly parser. The parser binary is bundled into the published package, so users do not need to install or compile the Pascal grammar separately.

The project can be built with:

npm install
npm run build

Contributing

Contributions, bug reports, formatting examples, and additional Pascal language test cases are welcome.

See CONTRIBUTING.md.

License

See LICENSE.