d3-array#InternMap JavaScript Examples

The following examples show how to use d3-array#InternMap. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source File: ordinal.js    From cs-wiki with GNU General Public License v3.0 5 votes vote down vote up 
export default function ordinal() {
  var index = new InternMap(),
      domain = [],
      range = [],
      unknown = implicit;

  function scale(d) {
    let i = index.get(d);
    if (i === undefined) {
      if (unknown !== implicit) return unknown;
      index.set(d, i = domain.push(d) - 1);
    }
    return range[i % range.length];
  }

  scale.domain = function(_) {
    if (!arguments.length) return domain.slice();
    domain = [], index = new InternMap();
    for (const value of _) {
      if (index.has(value)) continue;
      index.set(value, domain.push(value) - 1);
    }
    return scale;
  };

  scale.range = function(_) {
    return arguments.length ? (range = Array.from(_), scale) : range.slice();
  };

  scale.unknown = function(_) {
    return arguments.length ? (unknown = _, scale) : unknown;
  };

  scale.copy = function() {
    return ordinal(domain, range).unknown(unknown);
  };

  initRange.apply(scale, arguments);

  return scale;
}