locat 0.1.0

A blazing fast, zero-copy ISO 6709 geographic coordinate parser and writer in Rust.

Features

Zero-copy: CRS identifiers borrow directly from the input string
no_std compatible: works without the standard library
All ISO 6709 notation forms: decimal degrees, degrees+minutes, DMS
Altitude & CRS: optional altitude (meters) and coordinate reference system identifier
Round-trip: Display impls produce valid ISO 6709 output
DFA-powered lexer: logos-based tokenizer classifies components in a single pass

Installation

[dependencies]
locat = "0.1"

Quick Start

use locat::parse;

// Decimal degrees (New York City)
let coord = parse("+40.7128-074.0060/").unwrap();
let (lat, lon): (f64, f64) = coord.to_decimal_degrees();
assert!((lat - 40.7128).abs() < 1e-10);
assert!((lon - (-74.006)).abs() < 1e-10);

// Degrees, minutes, seconds
let coord = parse("+404243-0740002/").unwrap();

// With altitude and CRS (Mount Everest)
let coord = parse("+27.5916+086.5640+8848CRSepsg4326/").unwrap();
assert!(coord.altitude().is_some());
assert_eq!(coord.crs().unwrap().as_str(), "epsg4326");

// Round-trip
let input = "+40.7128-074.0060/";
let coord = parse(input).unwrap();
assert_eq!(coord.to_string(), input);

Supported Formats

Form	Latitude	Longitude	Example
Degrees	`±DD[.D+]`	`±DDD[.D+]`	`+40.7128-074.0060/`
Deg+Min	`±DDMM[.M+]`	`±DDDMM[.M+]`	`+4042.77-07400.36/`
DMS	`±DDMMSS[.S+]`	`±DDDMMSS[.S+]`	`+404243.0-0740002.0/`

Optional trailing components: [±Altitude][CRS<id>]/

Benchmarks

Measured on Apple Silicon with cargo bench (Criterion). All times are per-operation.

Parse (single coordinate)

Format	Time	Throughput
Minimal (`+00+000/`)	~18 ns	424 MiB/s
DMS integer (`+404243-0740002/`)	~22 ns	704 MiB/s
Decimal degrees (`+40.7128-074.0060/`)	~27 ns	634 MiB/s
Deg+Min (`+4042.7700-07400.3600/`)	~30 ns	708 MiB/s
DMS decimal (`+404243.123000-0740002.456000/`)	~34 ns	840 MiB/s
With altitude (`+27.5916+086.5640+8848/`)	~32 ns	680 MiB/s
With altitude+CRS (`+27.5916+086.5640+8848CRSepsg4326/`)	~37 ns	884 MiB/s

Round-trip (parse + `Display`)

Format	Time
DMS integer	~184 ns
Minimal	~180 ns
DMS decimal	~339 ns
Decimal degrees	~489 ns
Deg+Min	~497 ns
With altitude	~556 ns
With altitude+CRS	~622 ns

Conversion

to_decimal_degrees() completes in ~1 ns regardless of input format.

Batch throughput

Parsing 1,000 mixed-format coordinates: ~48 µs (~430 MiB/s).

Run benchmarks yourself:

cargo bench

License

locat is under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE, LICENSE-MIT for details.