Kaval 🌱

Kaval is a lightweight, human-friendly configuration language for Go applications. It provides a simple syntax for expressing structured data with fields, lists, and key-value pairs.

Kaval, version=1.0.0, ^enabled, !deprecated, features=simple;human-readable;flexible, 
settings=theme:dark;indent:4;display:compact

✨ Features

🔤 Clean, minimal syntax
No curly braces, no complex nesting. Friendly to read and write by humans
📏 Compact
Minimal syntax overhead, no deep nesting to navigate
🔄 Convenient boolean toggles
Use ^feature to enable, !feature to disable
📋 Lists and maps
Simple syntax for collections: tags=red;green;blue font=family:Arial;size:12
⚡ Event-based parser
Efficient parsing and serialization with a streaming parser API
🔨 Fluent builder API
Programmatically create kaval strings
🧩 Zero dependencies
Just pure Go standard library, no reflect used

📦 Installation

go get -u github.com/0x5a17ed/kaval

🚀 Quick Start

🔍 Parsing Kaval

package main

import (
	"fmt"
	
	"github.com/0x5a17ed/kaval"
)

func main() {
	input := "^enabled, name=john, settings=theme:dark;fontSize:14"
	for event := range kaval.Parse(input) {
		switch e := event.(type) {
		case kaval.ListStartEvent:
			fmt.Printf(" ListStart:\n")
		case kaval.ListEndEvent:
			fmt.Printf("   ListEnd:\n")
		case kaval.MapStartEvent:
			fmt.Printf("  MapStart:\n")
		case kaval.MapEndEvent:
			fmt.Printf("    MapEnd:\n")
		case kaval.ValueEvent:
			fmt.Printf("     Value: %s\n", e.Value)
		case kaval.MapKeyEvent:
			fmt.Printf("       Key: %s\n", e.Value)
		}
	}
}

// Output:
//  MapStart:
//       Key: enabled (identifier)
//     Value: true (boolean)
//       Key: name (identifier)
//     Value: john (identifier)
//       Key: settings (identifier)
//  MapStart:
//       Key: theme (identifier)
//     Value: dark (identifier)
//       Key: fontSize (identifier)
//     Value: 14 (number)
//    MapEnd:
//    MapEnd:

✏️ Creating Kaval

package main

import (
	"fmt"

	"github.com/0x5a17ed/kaval"
)

func main() {
	builder := kaval.NewBuilder()
	result := builder.
		Enable("feature").
		Labeled("name", "john").
		LabeledList("tags", "dev", "prod").
		LabeledDict("settings", "theme", "dark", "fontSize", 14).
		String()

	fmt.Println(result)
}

// Output: ^feature,name=john,tags=dev;prod,settings=theme:dark;fontSize:14

📝 Syntax

Kaval uses a simple, flat structure:

Fields are comma-separated: name=john, age=30
Boolean toggles use prefixes: ^enabled, !disabled
Lists use semicolons: tags=red;green;blue
Maps (key-value pairs) use colon and semicolon: settings=theme:dark;fontSize:14
Blank spaces are allowed around syntax elements

🧪 Data Types

Strings: name=john or message="Hello, world!" (quotes for special chars)
Numbers: age=30, pi=3.14, hex=0xFF, binary=0b1010
Booleans: active=true or valid=false
Lists: colors=red;green;blue
Maps: settings=theme:dark;fontSize:14
Null: value=nil

📚 Detailed Usage

🛠️ Builder with Options

package main

import (
	"fmt"

	"github.com/0x5a17ed/kaval"
)

func main() {
	options := kaval.BuilderOptions{
		SpaceAfterFieldSeparator:   true,
		SpaceAfterListSeparator:    true,
		SpaceAfterPairsSeparator:   true,
		SpaceAroundFieldAssignment: true,
	}

	builder := kaval.NewBuilder(options)
	result := builder.
		Enable("feature").
		Labeled("name", "john").
		LabeledList("tags", "dev", "prod").
		LabeledDict("settings", "theme", "dark", "fontSize", 14).
		String()

	fmt.Println(result)
}

// Output: ^feature, name = john, tags = dev; prod, settings = theme: dark; fontSize: 14

📜 License

This project is licensed under the 0BSD Licence — see the LICENCE file for details.

Made with ❤️ for structured data 🌟

kaval-lang/kaval