import { crossProduct } from './cross-product';
import { JOINS } from '../constants';
import { union } from './union';
/**
* {@link https://www.geeksforgeeks.org/extended-operators-in-relational-algebra/ | Left outer join} between two
* {@link /muze/docs/api-datamodel | DataModel} instances is a kind of join that ensures that all the tuples from the
* left {@link /muze/docs/api-datamodel | DataModel} are present in the resulatant
* {@link /muze/docs/api-datamodel | DataModel}. This operator takes a predicate which gets called for every
* combination of tuples (created by cartesian product). Based on the value of predicate the equality is established
* between two DataModel.
*
* @example
* //@preamble_start
* Promise.all([loadData('/static/cars.json'), loadData('/static/cars-schema.json')]).then(function (params) {
* const data = params[0];
* const schema = params[1];
* const DataModel = muze.DataModel;
* const dm = new DataModel(data, schema);
* //@preamble_end
* // DataModel instance is created from https://www.charts.com/static/cars.json data,
* // https://www.charts.com/static/cars-schema.json schema and assigned to variable dm. DataModel is extracted from
* // muze namespace and assigned to the variable DataModel.
*
* // Creates two small DataModel instance from the original DataModel instance, which will be joined using left outer
* // join.
* let makerDM = dm.groupBy(['Origin', 'Maker']).project(['Origin', 'Maker']);
* let nameDM = dm.project(['Name','Miles_per_Gallon']);
*
* const leftOuterJoin = DataModel.Operators.leftOuterJoin;
* let outputDM = leftOuterJoin(makerDM, nameDM,
* (makerDM, nameDM) => makerDM.Maker.value === nameDM.Name.value.split(/\s/)[0]);
* //@preamble_start
* printDM(outputDM);
* });
* //@preamble_end
*
* @public
* @segment Operators
*
* @param {DataModel} leftDm Instance of DataModel
* @param {DataModel} rightDm Instance of DataModel
* @param {SelectionPredicate} filterFn - The predicate function that will filter the result of the crossProduct.
*
* @return {DataModel} New DataModel instance created after the left outer join operation.
*/
export function leftOuterJoin (leftDm, rightDm, filterFn) {
return crossProduct(leftDm, rightDm, filterFn, false, JOINS.LEFTOUTER);
}
/**
* {@link https://www.geeksforgeeks.org/extended-operators-in-relational-algebra/ | Right outer join} between two
* {@link /muze/docs/api-datamodel | DataModel} instances is a kind of join that ensures that all the tuples from the
* right {@link /muze/docs/api-datamodel | DataModel} are present in the resulatant
* {@link /muze/docs/api-datamodel | DataModel}. This operator takes a predicate which gets called for every
* combination of tuples (created by cartesian product). Based on the value of predicate the equality is established
* between two DataModel.
*
* @example
* //@preamble_start
* Promise.all([loadData('/static/cars.json'), loadData('/static/cars-schema.json')]).then(function (params) {
* const data = params[0];
* const schema = params[1];
* const DataModel = muze.DataModel;
* const dm = new DataModel(data, schema);
* //@preamble_end
* // DataModel instance is created from https://www.charts.com/static/cars.json data,
* // https://www.charts.com/static/cars-schema.json schema and assigned to variable dm. DataModel is extracted from
* // muze namespace and assigned to the variable DataModel.
*
* // Creates two small DataModel instance from the original DataModel instance, which will be joined using left outer
* // join.
* let makerDM = dm.groupBy(['Origin', 'Maker']).project(['Origin', 'Maker']);
* let nameDM = dm.project(['Name','Miles_per_Gallon']);
*
* const rightOuterJoin = DataModel.Operators.rightOuterJoin;
* let outputDM = rightOuterJoin(makerDM, nameDM,
* (makerDM, nameDM) => makerDM.Maker.value === nameDM.Name.value.split(/\s/)[0]);
* //@preamble_start
* printDM(outputDM);
* });
* //@preamble_end
*
* @public
* @segment Operators
*
* @param {DataModel} leftDm Instance of DataModel
* @param {DataModel} rightDm Instance of DataModel
* @param {SelectionPredicate} filterFn - The predicate function that will filter the result of the crossProduct.
*
* @return {DataModel} New DataModel instance created after the left outer join operation.
*/
export function rightOuterJoin (dataModel1, dataModel2, filterFn) {
return crossProduct(dataModel2, dataModel1, (leftDmFields, rightDmFields) =>
filterFn(rightDmFields, leftDmFields), false, JOINS.RIGHTOUTER);
}
/**
* {@link https://www.geeksforgeeks.org/extended-operators-in-relational-algebra/ | Full outer join} between two
* {@link /muze/docs/api-datamodel | DataModel} instances is a kind of join that ensures that all the tuples from the
* left {@link /muze/docs/api-datamodel | DataModel} and right {@link /muze/docs/api-datamodel | DataModel} are present
* in the resulatant {@link /muze/docs/api-datamodel | DataModel}. This operator takes a predicate which gets
* called for every combination of tuples (created by cartesian product). Based on the value of predicate the equality
* is established between two DataModel.
*
* @example
* //@preamble_start
* Promise.all([loadData('/static/cars.json'), loadData('/static/cars-schema.json')]).then(function (params) {
* const data = params[0];
* const schema = params[1];
* const DataModel = muze.DataModel;
* const dm = new DataModel(data, schema);
* //@preamble_end
* // DataModel instance is created from https://www.charts.com/static/cars.json data,
* // https://www.charts.com/static/cars-schema.json schema and assigned to variable dm. DataModel is extracted from
* // muze namespace and assigned to the variable DataModel.
*
* // Creates two small DataModel instance from the original DataModel instance, which will be joined using left outer
* // join.
* let makerDM = dm.groupBy(['Origin', 'Maker']).project(['Origin', 'Maker']);
* let nameDM = dm.project(['Name','Miles_per_Gallon']);
*
* const fullOuterJoin = DataModel.Operators.fullOuterJoin;
* let outputDM = fullOuterJoin(makerDM, nameDM,
* (makerDM, nameDM) => makerDM.Maker.value === nameDM.Name.value.split(/\s/)[0]);
* //@preamble_start
* printDM(outputDM);
* });
* //@preamble_end
*
* @public
* @segment Operators
*
* @param {DataModel} leftDm Instance of DataModel
* @param {DataModel} rightDm Instance of DataModel
* @param {SelectionPredicate} filterFn - The predicate function that will filter the result of the crossProduct.
*
* @return {DataModel} New DataModel instance created after the left outer join operation.
*/
export function fullOuterJoin (dataModel1, dataModel2, filterFn) {
return union(leftOuterJoin(dataModel1, dataModel2, filterFn), rightOuterJoin(dataModel1, dataModel2, filterFn));
}