Header Config Parser

A Rust library for parsing hierarchical configuration files using Markdown-style headers, transforming nested sections into flat key-value pairs with namespaced keys.

Features

📂 Header-based namespacing
➕ Automatic key hierarchy flattening
🧹 Whitespace-tolerant parsing
🚦 Empty value handling
🔍 Simple string-based lookups

Installation

Add to your Cargo.toml:

[dependencies]
header-config = "0.1"

Usage

use header_config::{parse_config, parse_config_str};

let from_file = parse_config(std::path::Path::new("config.md"))?;
let from_text = parse_config_str("# Section\n\nkey value\n")?;

Both return an IndexMap<Box<str>, Box<str>> of namespaced keys; parse_config_str parses an in-memory string (for example a section embedded in a larger file or a network response).

File Format Specification

Basic Syntax

# Server Config

port 8080
timeout 30

# Database

host localhost
user admin

## Replica

host replica.db

Key Features

Headers create namespaces using # symbols
Keys are whitespace-separated from values
Empty values allowed (key without value)
Nesting with subheaders (## Subsection)

Parsing Rules

Header levels determine namespace depth
It's not allowed to go more than one header level deeper at once
Keys inherit all parent header namespaces
Case-sensitive matching
Duplicates aren't allowed

Example

The format looks like this:

key1 value
key2

# HeaderA

key1 value
key2

# HeaderB

key1 value
key2

## SubheaderA

key1 value
key2

## SubheaderB

key1 value
key2

The created mapping will be something like this:

"key1" -> "value"
"key2" -> ""
"HeaderA:key1" -> "value"
"HeaderA:key2" -> ""
"HeaderB:key1" -> "value"
"HeaderB:key2" -> ""
"HeaderB:SubheaderA:key1" -> "value"
"HeaderB:SubheaderA:key2" -> ""
"HeaderB:SubheaderB:key1" -> "value"
"HeaderB:SubheaderB:key2" -> ""

header-config 0.1.7