D3 Helpers

d3-helpers is a collection of small, functional utility functions designed to streamline common D3 callback patterns, particularly for D3.js version 3.0. It aims to improve code readability by allowing a left-to-right composition style for data property access and function application within D3's data-driven methods, such as `d3.svg.line().x()`. The package, currently at version 0.3.0, was last published in 2014 and is not actively maintained. It was developed to abstract away repetitive callback definitions like `function (d) { return x(new Date(d.date)); }` into more concise and explicit chains like `d3h('date', d3h.newDate, x)`. Its primary differentiator was simplifying D3's functional programming aspects at a time when D3's API encouraged verbose callback structures. It offers utilities for property access, type conversion, and handling data `d` and index `i` arguments in a declarative manner.