Function parseParameter

docs/tests/v2/es6/js/sanddance.js:131436–131448

* Parse a single parameter.

(spec, ctx, params)

function parseParameter(spec, ctx, params) {
  if (!spec || !(0, _vegaUtil.isObject)(spec)) return spec;

  for (var i = 0, n = PARSERS.length, p; i < n; ++i) {
    p = PARSERS[i];

    if ((0, _vegaUtil.hasOwnProperty)(spec, p.key)) {
      return p.parse(spec, ctx, params);
    }
  }

  return spec;
}
/** Reference parsers. */