/* * @copyright (c) 2016, Philipp Thürwächter & Pattrick Hüper * @copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos * @license BSD-3-Clause (see LICENSE in the root directory of this source tree) */ import { abstractMethodFail } from '../assert'; import { Enum } from '../Enum'; /** * Strategy for querying a temporal object. * * Queries are a key tool for extracting information from temporal objects. * They exist to externalize the process of querying, permitting different * approaches, as per the strategy design pattern. * Examples might be a query that checks if the date is the day before February 29th * in a leap year, or calculates the number of days to your next birthday. * * The {@link TemporalField} interface provides another mechanism for querying * temporal objects. That interface is limited to returning a `long`. * By contrast, queries can return any type. * * There are two equivalent ways of using a {@link TemporalQuery}. * The first is to invoke the method on this interface directly. * The second is to use {@link TemporalAccessor#query}: *
* // these two lines are equivalent, but the second approach is recommended * temporal = thisQuery.queryFrom(temporal); * temporal = temporal.query(thisQuery); ** It is recommended to use the second approach, {@link query}, * as it is a lot clearer to read in code. * * The most common implementations are method references, such as * {@link LocalDate::from} and {@link ZoneId::from}. * Further implementations are on {@link TemporalQueries}. * Queries may also be defined by applications. * * ### Specification for implementors * * This interface places no restrictions on the mutability of implementations, * however immutability is strongly recommended. * * @interface */ export class TemporalQuery extends Enum { /** * Queries the specified temporal object. * * This queries the specified temporal object to return an object using the logic * encapsulated in the implementing class. * Examples might be a query that checks if the date is the day before February 29th * in a leap year, or calculates the number of days to your next birthday. * * There are two equivalent ways of using this method. * The first is to invoke this method directly. * The second is to use {@link TemporalAccessor#query}: *
* // these two lines are equivalent, but the second approach is recommended
* temporal = thisQuery.queryFrom(temporal);
* temporal = temporal.query(thisQuery);
*
* It is recommended to use the second approach, {@link query},
* as it is a lot clearer to read in code.
*
* ### Specification for implementors
*
* The implementation must take the input object and query it.
* The implementation defines the logic of the query and is responsible for
* documenting that logic.
* It may use any method on {@link TemporalAccessor} to determine the result.
* The input object must not be altered.
*
* The input temporal object may be in a calendar system other than ISO.
* Implementations may choose to document compatibility with other calendar systems,
* or reject non-ISO temporal objects by querying the chronology (see {@link TemporalQueries#chronology}).
*
* This method may be called from multiple threads in parallel.
* It must be thread-safe when invoked.
*
* @param {TemporalAccessor} temporal the temporal object to query, not null
* @return the queried value, may return null to indicate not found
* @throws DateTimeException if unable to query
* @throws ArithmeticException if numeric overflow occurs
*/
// eslint-disable-next-line no-unused-vars
queryFrom(temporal){
abstractMethodFail('queryFrom');
}
}
/**
* @private
*
* Factory to create something similar to the JSR-310 {TemporalQuery} interface, takes a function and returns a new TemporalQuery object that presents that function
* as the queryFrom() function.
* @param name for the underlying Enum
* @param queryFromFunction
*/
export function createTemporalQuery(name, queryFromFunction) {
class ExtendedTemporalQuery extends TemporalQuery {
}
ExtendedTemporalQuery.prototype.queryFrom = queryFromFunction;
return new ExtendedTemporalQuery(name);
}