zon - "zon is not json"

zon is a declarative, extensible build tool written in Go. It interprets .zon files—JSON-inspired configuration files with support for evaluation, includes, function definitions, and build recipes. It’s designed to be minimal yet powerful, with strong inspiration from tools like Nix and JSON-e, and suitable for building packages, managing dotfiles, or orchestrating complex workflows.

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✨ Features

• Declarative and expressive syntax: inspired by JSON, with extensions for expressions, interpolation, and functions.
• Build caching via content-addressable storage.
• Reproducible output paths, unless explicitly marked impure.
• Parallel and serial evaluation modes.
• Native support for:
  • let/in bindings,
  • include statements,
  • output { ... } build expressions,
  • string interpolation and escape sequences.
• Output as symlinks, JSON, or raw directory paths.
• Can optionally generate a DOT dependency graph.

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📦 Example

A simple .zon file for building suckless tools:

let
  util = include ./util.zon
in output {
  with util.merge,
  "name": "apps",
  "prefix": ".local",
  "paths": [
    output {
      with util.unpack,
      "archive": output {
        with util.fetch,
        "url": "https://dl.suckless.org/tools/dmenu-5.2.tar.gz",
        "checksum": "3829528c849db6f903676fe7e6a48f3735505b6d"
      },
      "name": "dmenu",
      "output": ''
        make PREFIX=$out install
      ''
    }
  ]
}

You can run this with:

zon apps.zon

This fetches, unpacks, and builds dmenu, outputting to a deterministic directory in cache/store.

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🔧 Command Line Usage

zon [options] <file.zon> [key=value ...]

Options

Flag	Description
-f, --force	Force rebuilding of all outputs
-d, --dry	Dry-run: do not execute anything
-s, --serial	Run builders sequentially instead of in parallel
-o, --output	Symlink output to given name (default: result)
--no-result	Disable symlink creation
--json	Print result as JSON
-g, --clean	Clean orphaned outputs in the store
--graph	Write DOT graph to specified file
--cache	Cache directory (default: cache/store)
--log	Log directory (default: cache/log)
--interpreter	Interpreter to use for inline scripts (default: sh)

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🛠️ Built-in Expressions

• output { ... }: defines a build step. Attributes include:
  • "builder" or "output" (script),
  • "args" (array of string args),
  • "source" (working directory),
  • "impure" (disables caching),
  • custom env vars.
• include path: includes and evaluates another .zon file.
• let ... in ...: scoped variable definitions.
• with expr, ...: merges attribute sets (maps).
• Strings support "\(expression)" interpolation.

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🧠 Design

• Everything is an expression: there are no statements.
• Outputs are hashed based on the full input expression unless marked impure.
• Evaluation is lazy but deterministic.
• Errors include file and position information for debugging.

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📜 License

Beautiful zlib-license