content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package io.activej.common.function;
  
  import io.activej.common.exception.FatalErrorHandler;
  import io.activej.common.exception.UncheckedException;
  
  import java.util.function.Supplier;
  
  import static io.activej.common.exception.FatalErrorHandler.handleError;
  
  /**
   * Represents a {@link Supplier} capable of throwing exceptions
   */
  @FunctionalInterface
  public interface SupplierEx<T> {
  	T get() throws Exception;
  
  	/**
  	 * Creates a {@code SupplierEx} out of {@link Supplier}
  	 * <p>
  	 * If given supplier throws {@link UncheckedException}, its cause will be propagated
  	 *
  	 * @param uncheckedFn original {@link Supplier}
  	 * @return a supplier capable of throwing exceptions
  	 */
  	static <T> SupplierEx<T> of(Supplier<T> uncheckedFn) {
  		return () -> {
  			try {
  				return uncheckedFn.get();
  			} catch (UncheckedException ex) {
  				throw ex.getCause();
  			}
  		};
  	}
  
  	/**
  	 * Creates a {@link Supplier} out of {@code SupplierEx}
  	 * <p>
  	 * If given supplier throws a checked exception, it will be wrapped into {@link UncheckedException}
  	 * and rethrown
  	 * <p>
  	 * Unchecked exceptions will be handled by thread's {@link FatalErrorHandler}
  	 *
  	 * @param checkedFn original {@code SupplierEx}
  	 * @return a supplier
  	 */
  	static <T> Supplier<T> uncheckedOf(SupplierEx<T> checkedFn) {
  		return () -> {
  			try {
  				return checkedFn.get();
  			} catch (Exception ex) {
  				handleError(ex, checkedFn);
  				throw UncheckedException.of(ex);
  			}
  		};
  	}
  }
  