xmonad-config/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Overview

This is a personal XMonad + Xmobar configuration built as a Haskell project using Nix flakes. The project uses Relude as a custom Prelude and follows a strict, opinionated Haskell development workflow.

Build System

This project uses just for task running and Nix flakes for reproducible builds:

# List available commands
just

# Build the project
just build

# Run XMonad executable
just run xmonad

# Run XMobar executable
just run xmobar

# Start REPL
just repl

# Access Hoogle documentation (serves at http://127.0.0.1:8888)
just docs

Nix Commands

# Update flake inputs
nix flake update

# Build all outputs
nix --accept-flake-config run github:juspay/omnix ci

# Run without installing
nix run .

# Enter development shell (or use direnv)
nix develop

Pre-commit Hooks

Pre-commit hooks are automatically configured in the Nix shell and include:

• fourmolu for Haskell formatting (with FOURMOLU_DISABLE/ENABLE pragmas where needed)
• nixpkgs-fmt for Nix formatting
• hlint for Haskell linting

Run manually: pre-commit run -a

Project Structure

The repository follows a standard Cabal package layout:

• src/xmonad.hs - Main XMonad configuration (executable entry point)
• src/xmobar.hs - XMobar status bar configuration (executable entry point)
• src/XMonadConfig/GruvboxMaterial.hs - Shared color scheme module providing xmobar escape codes

Two Executables

The project builds two separate executables defined in xmonad-config.cabal:

1. xmonad - The window manager configuration
2. xmobar - The status bar configuration

Both share the XMonadConfig.GruvboxMaterial module for consistent theming.

Architecture

XMonad Configuration (src/xmonad.hs)

The configuration is built compositionally using function application:

main = xmonad
     . docks
     . ewmhFullscreen
     . ewmh
     . withNavigation2DConfig def
     . withSB myXmobar
     $ myConfig

Key architectural components:

• Navigation2D: Directional window and screen navigation using arrow keys and Navigation2D module
• Custom keybindings: Leader-key approach (M-a prefix) for spawning applications and layout switching
• Window manipulation: Uses XMonad.Actions.RotSlaves for window rotation (mimics wezterm behavior)
• Layout system: Three layouts - dynamic tiling, maximised, and fullscreen
• StatusBar integration: Communicates with xmobar via _XMONAD_LOG_1 X property
• Mnemonic bindings: Control (M-C) for layout manipulation, Shift (M-S) for window operations

XMobar Configuration (src/xmobar.hs)

Defines a status bar with:

• System information (uname, uptime, disk usage)
• Weather data (station YPJT)
• Date/time
• XMonad workspace/layout information from _XMONAD_LOG_1 property

The bar is positioned statically for a multi-monitor setup (positioned at x=1920).

Color Scheme Module

XMonadConfig.GruvboxMaterial exports color functions that wrap strings in xmobar color escape codes. This ensures consistent theming across both XMonad and XMobar configurations.

Haskell Configuration

Custom Prelude

Uses Relude instead of standard Prelude, configured in xmonad-config.cabal:

mixins:
  base hiding (Prelude),
  relude (Relude as Prelude, Relude.Container.One),
  relude

Default Extensions

The following extensions are enabled project-wide:

• DataKinds, DerivingStrategies, DerivingVia
• LambdaCase, MultiWayIf, NoStarIsType
• OverloadedStrings, StrictData, TypeFamilies, ViewPatterns

GHC Options

Strict compilation with extensive warnings:

• -Wall
• -Wincomplete-record-updates, -Wincomplete-uni-patterns
• -Wmissing-deriving-strategies, -Wunused-foralls
• -fprint-explicit-foralls, -fprint-explicit-kinds

Development Workflow

1. The project uses haskell-flake via flake-parts for Haskell package management
2. HLS (Haskell Language Server) is available but checks are disabled in devShell (hlsCheck.enable = false)
3. Static analysis via stan is enabled for the xmonad-config package
4. The project filters projectRoot in nix/modules/flake/haskell.nix to avoid unnecessary rebuilds

Key Dependencies

• xmonad, xmonad-contrib - Core window manager libraries
• xmobar - Status bar library
• relude - Alternative Prelude
• optics-core - For lens-style accessors
• data-default - Default instances for configuration