content: /*
   * Copyright © 2018-2025 Commonwealth Scientific and Industrial Research
   * Organisation (CSIRO) ABN 41 687 119 230.
   *
   * 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 au.csiro.pathling.fhirpath.function;
  
  import static java.util.Objects.requireNonNull;
  
  import au.csiro.pathling.fhirpath.annotations.Name;
  import au.csiro.pathling.fhirpath.collection.Collection;
  import jakarta.annotation.Nonnull;
  
  /**
   * Represents a function in FHIRPath.
   *
   * @author John Grimes
   */
  public interface NamedFunction {
  
    /**
     * @return the name of this function
     */
    @Nonnull
    default String name() {
      return requireNonNull(this.getClass().getAnnotation(Name.class)).value();
    }
  
    /**
     * Invokes this function with the specified inputs.
     *
     * @param input a {@link FunctionInput} object
     * @return a {@link Collection} object representing the resulting expression
     */
    @Nonnull
    default Collection invoke(@Nonnull final FunctionInput input) {
      throw new UnsupportedOperationException("Not implemented: " + name());
    }
  
  }
  