Function cache

docs/tests/v2/es6/js/sanddance.js:135647–135676

(scope, ds, name, optype, field, counts, index)

}

function cache(scope, ds, name, optype, field, counts, index) {
  var cache = ds[name] || (ds[name] = {}),
      sort = (0, _util.sortKey)(counts),
      k = fieldKey(field),
      v,
      op;

  if (k != null) {
    scope = ds.scope;
    k = k + (sort ? '|' + sort : '');
    v = cache[k];
  }

  if (!v) {
    var params = counts ? {
      field: _util.keyFieldRef,
      pulse: ds.countsRef(scope, field, counts)
    } : {
      field: scope.fieldRef(field),
      pulse: (0, _util.ref)(ds.output)
    };
    if (sort) params.sort = scope.sortRef(counts);
    op = scope.add((0, _util.entry)(optype, undefined, params));
    if (index) ds.index[field] = op;
    v = (0, _util.ref)(op);
    if (k != null) cache[k] = v;
  }

  return v;
}

prototype.tuplesRef = function () {
  return (0, _util.ref)(this.values);