HuwCampbell / piano

A library for lookup of times for entities in a chord descriptor.

Piano

a musical instrument in which hammers, operated from a keyboard of ivories, strike its cast of strings

Overview

This library provides parsing of ivory chord descriptor files and functionality to lookup the times associated with an entity.

Chord Descriptor Format

Unsorted, pipe-separated, entity and inclusive date.

<entity>|<inclusive date>

For example:

E+0072|2016-07-25
E+8680|2016-02-29
E+3787|2016-07-18
E+0190|2016-03-14
E+0022|2016-05-10

API

This library is primarily designed to be consumed from C using the following API:

//
// Lookup an entity in the chord descriptor.
//
// If the entity is found, its array of chord times are returned, sorted oldest
// to newest. The times returned are an exclusive bound on the scope of the
// chord query for the entity requested.
//
// Times are in seconds since 1600-03-01 (ivory epoch).
//
// If the entity is not found, the |out_count| will be set to 0.
//
error_t piano_lookup (
    piano_t *piano
  , size_t entity_size
  , const char *entity
  , int64_t *out_count
  , int64_t *out_times
  );