Your IP : 216.73.216.17
var TUPLE_ID_KEY = Symbol('vega_id'),
TUPLE_ID = 1;
/**
* Resets the internal tuple id counter to one.
*/
export function reset() {
TUPLE_ID = 1;
}
/**
* Checks if an input value is a registered tuple.
* @param {*} t - The value to check.
* @return {boolean} True if the input is a tuple, false otherwise.
*/
export function isTuple(t) {
return !!(t && tupleid(t));
}
/**
* Returns the id of a tuple.
* @param {object} t - The input tuple.
* @return {*} the tuple id.
*/
export function tupleid(t) {
return t[TUPLE_ID_KEY];
}
/**
* Sets the id of a tuple.
* @param {object} t - The input tuple.
* @param {*} id - The id value to set.
* @return {object} the input tuple.
*/
function setid(t, id) {
t[TUPLE_ID_KEY] = id;
return t;
}
/**
* Ingest an object or value as a data tuple.
* If the input value is an object, an id field will be added to it. For
* efficiency, the input object is modified directly. A copy is not made.
* If the input value is a literal, it will be wrapped in a new object
* instance, with the value accessible as the 'data' property.
* @param datum - The value to ingest.
* @return {object} The ingested data tuple.
*/
export function ingest(datum) {
var t = (datum === Object(datum)) ? datum : {data: datum};
return tupleid(t) ? t : setid(t, TUPLE_ID++);
}
/**
* Given a source tuple, return a derived copy.
* @param {object} t - The source tuple.
* @return {object} The derived tuple.
*/
export function derive(t) {
return rederive(t, ingest({}));
}
/**
* Rederive a derived tuple by copying values from the source tuple.
* @param {object} t - The source tuple.
* @param {object} d - The derived tuple.
* @return {object} The derived tuple.
*/
export function rederive(t, d) {
for (var k in t) d[k] = t[k];
return d;
}
/**
* Replace an existing tuple with a new tuple.
* @param {object} t - The existing data tuple.
* @param {object} d - The new tuple that replaces the old.
* @return {object} The new tuple.
*/
export function replace(t, d) {
return setid(d, tupleid(t));
}