Zini

A high-performance, zero-allocation INI-style configuration file parser for .NET 10 with Microsoft.Extensions.Configuration integration.

Features

• Zero-allocation hot path — uses SearchValues<char> for SIMD-accelerated parsing
• Immutable output — returns ConfigDocument backed by FrozenDictionary instances
• Round-trip support — ConfigWriter serializes back to INI with smart quoting and quote escaping
• Case-insensitive sections and keys with OrdinalIgnoreCase comparison
• Section merging — duplicate sections merge automatically (last-write-wins for keys)
• Quoted values — preserves whitespace and comment characters inside "..."
• Inline comments — # and ; stripped from unquoted values
• Global keys — keys before any section header are supported
• Configuration integration — drop-in IConfigurationBuilder.AddConfigFile() extension

Installation

Package	Status
Zini
Zini.Configuration

dotnet add package Zini.Configuration  # IConfigurationBuilder support

Quick Start

Direct Parsing

using Zini;

var doc = ConfigParser.Parse("""
    # Application settings
    app_name = MyApp

    [Server]
    host = localhost
    port = 8080

    [Database]
    connection = "Server=db;Port=5432;User=""admin"""
    """);

// Indexer access
var host = doc["Server"]["host"];           // "localhost"

// Safe access (returns null if missing)
var port = doc.GetValue("Server", "port");  // "8080"
var appName = doc.GetGlobalValue("app_name"); // "MyApp"

// Metadata
doc.SectionNames           // ["Server", "Database"]
doc.HasGlobalKeys          // true
doc.ContainsSection("Server") // true

Writing Back to INI

var doc = ConfigParser.Parse(input);

// Write to string
var output = ConfigWriter.Write(doc);

// Write to TextWriter (sync or async)
ConfigWriter.Write(textWriter, doc);
await ConfigWriter.WriteAsync(streamWriter, doc);

With Microsoft.Extensions.Configuration

using Microsoft.Extensions.Configuration;
using Zini.Configuration;

var configuration = new ConfigurationBuilder()
    .AddConfigFile("appsettings.ini", optional: false, reloadOnChange: true)
    .Build();

var host = configuration["Server:host"];   // "localhost"
var appName = configuration["app_name"];   // "MyApp" (global keys have no prefix)

Format Specification

See docs/config-format-spec.md for the full format specification including quoting rules, merging behavior, and error handling.

Building

dotnet build Zini.slnx
dotnet test Zini.slnx

License

MIT