# `fastobo` [](https://github.com/fastobo/fastobo/stargazers)
*Faultless AST for Open Biomedical Ontologies.*
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[](https://github.com/fastobo/fastobo)
[](https://crates.io/crates/fastobo)
[](https://docs.rs/fastobo)
[](https://github.com/fastobo/fastobo/blob/master/CHANGELOG.md)
[](https://github.com/fastobo/fastobo/issues)
## Overview
This library provides a mostly-complete implementation of the
[OBO flat file format 1.4](http://owlcollab.github.io/oboformat/doc/obo-syntax.html).
* **Data structures** - `fastobo` provides a complete owned AST for the
OBO language, with constructors and covenience traits where applicable.
There is a plan to provide borrowed data structures as well, to be able
to build a view of an OBO document from borrowed data.
* **Parsing** - The parser is implemented using [pest](http://pest.rs/),
and is reexported from the [`fastobo-syntax`](https://crates.io/crates/fastobo-syntax)
crate. Most structures implement the [`FromPair`](./parser/trait.FromPair.html)
trait which allows to build a data structure from a stream of pest tokens.
* **Errors** - All functions in that crate that return a `Result` will
always use the `Error` struct defined in the `error` module. Errors
reported by pest are very meaningful, and can give the exact location
of a syntax error encountered by the parser.
* **Semantics** - This library exports specific methods that can be used
to edit an OBO syntax tree with the semantics expected in the format
guide: mapping identifiers to URLs, adding default namespaces, or
expanding entity frames using `treat-xrefs` macros.
*Warning: this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html),
but the API is likely to change a lot before the release of a stable 1.0.*
## Features
All the following features are enabled by default, but can be disabled and
cherry-picked using the `default-features = false` option in the `Cargo.toml`
manifest of your project:
* **`memchr`** - Use the `memchr` library to improve parser speed when
searching for a particular character in a buffer.
* **`semantics`** - Compile additional methods to check the validity of an OBO
document on the semantic level, and implementation of macros to transform OBO
documents in place.
## Usage
Add `fastobo` to the `[dependencies]` sections of your `Cargo.toml` manifest:
```toml
[dependencies]
fastobo = "0.3.0"
```
The `OboDoc` struct acts as the root of the AST. Use `OboDoc::from_stream` to load an OBO document
from a [`BufRead`](https://doc.rust-lang.org/std/io/trait.BufRead.html) implementor
(use [`std::io::BufReader`](https://doc.rust-lang.org/std/io/struct.BufReader.html) if needed):
```rust
extern crate fastobo;
extern crate ureq;
fn main() {
let response = ureq::get("http://purl.obolibrary.org/obo/ms.obo").call();
let mut reader = std::io::BufReader::new(response.into_reader());
match fastobo::ast::OboDoc::from_stream(&mut reader) {
Ok(doc) => println!("Number of MS entities: {}", doc.entities().len()),
Err(e) => panic!("Could not parse the Mass-Spec Ontology: {}", e),
}
}
```
## See also
* [`fastobo-syntax`](https://crates.io/crates/fastobo-syntax): Standalone `pest` parser for the OBO
format version 1.4.
* [`fastobo-py`](https://pypi.org/project/fastobo/): Idiomatic Python bindings to this crate.
* [`fastobo-validator`](https://pypi.org/project/fastobo/): Standalone CLI to validate OBO files against the specification.
## Feedback
Found a bug ? Have an enhancement request ? Head over to the
[GitHub issue tracker](https://github.com/fastobo/fastobo/issues) of the project if
you need to report or ask something. If you are filling in on a bug, please include as much
information as you can about the issue, and try to recreate the same bug in a simple, easily
reproducible situation.
## About
This project is currently being developed by [Martin Larralde](https://github.com/althonos)
as part of a Master's Degree internship in the [BBOP team](http://berkeleybop.org/) of the
[Lawrence Berkeley National Laboratory](https://www.lbl.gov/), under the supervision of
[Chris Mungall](http://biosciences.lbl.gov/profiles/chris-mungall/).