Crate quandl_v3

Rust bindings for Quandl v3 API.

The goal of this crate is to offer a well documented, complete and easy to use interface to Quandl’s RESTful API.

This crate uses the rustc_serialize crate extensively and thus suffers from some of its limitation. Namely,

• When querying for the metadata of a dataset, the field type will be missing. This is due to type being a keyword in Rust. Use of this crate assumes knowledge of the layout of the queried data, so that field was not very important fortunately.

• Most public enum’s variants have non camel case names to match the naming convention of the API. The deserializer need the names to match to work properly, thus you will see Order::asc instead of the more readable Order::Ascending.

Some other design choices of this crate includes

• No runtime checking of the query created. This crate makes it as hard as statically possible to create an invalid query. However, the query will be checked by the Quandl API directly. On the bright side, we forward Quandl’s error messages/codes without pruning any information; and their error-reporting is very good.

• The inclusion of a batch_query function that allows users to submit a bunch of query at the same time. The function returns an iterator which gives the benefit of multithreading downloads and asynchronicity which are indispensable when doing data mining.

• We use the JSON Quandl API for everything but data queries as it often returns more information. When it comes to the data queries we use the CSV subset of the API as it is faster and allows to use the rust-csv crates which allow you to define your own structs to receive the data.

Simple example

extern crate quandl_v3;

use quandl_v3::Result;
use quandl_v3::prelude::*;

fn main() {
    let query = {
        let mut query = DataQuery::new("WIKI", "AAPL");

         query.order(Order::asc)
              .end_date(2016, 2, 29)
              .start_date(2016, 2, 1)
              .column_index(4);

         query
    };

    let response: Vec<(String, f64)> = query.send().unwrap();

    // Print the date and closing price for Apple's stock for the month of February 2016.
    for data in &response {
        println!("{} - {}", data.0, data.1);
    }
}

This crate is written in the hope it will be useful. I am in no way affiliated to Quandl and Quandl is not endorsing this crate in any way.

Some of the documentation in this crate has been directly copied from Quandl’s API Documentation (which is made evident from the links to that documentation directly in this crate’s documentation). Those obiously remains the intellectual property of Quandl and were paraphrased to make the use of this crate simpler.

Quandl’s Terms of Use

Modules

• prelude
  This crate’s public interface.

Structs

• ApiErrorResponse
  Struct for storing a Quandl API error response as-is.
• QuandlError
  Struct holding Quandl’s error code and corresponding message.

Enums

• Error
  Crate-wide error value. This enumerate the only four possible source of failures in this crate.

Type Aliases

• Result
  Crate-wide return type for functions which may fail.