github.com/aacfactory/fns@v1.2.86-0.20240310083819-80d667fc0a17/context/operators/map.go (about)

     1  /*
     2   * Copyright 2023 Wang Min Xiang
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   * 	http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   *
    16   */
    17  
    18  package operators
    19  
    20  import "github.com/aacfactory/fns/context"
    21  
    22  type MapFn[S any, D any] func(ctx context.Context, src S) (dst D, err error)
    23  
    24  func Map[S any, D any](ctx context.Context, src S, fn MapFn[S, D]) (dst D, err error) {
    25  	dst, err = fn(ctx, src)
    26  	return
    27  }
    28  
    29  func MapSlice[S any, D any](ctx context.Context, src []S, fn MapFn[S, D]) (dst []D, err error) {
    30  	dst = make([]D, 0, 1)
    31  	if src == nil || len(src) == 0 {
    32  		return
    33  	}
    34  	for _, s := range src {
    35  		d, mapErr := fn(ctx, s)
    36  		if mapErr != nil {
    37  			err = mapErr
    38  			return
    39  		}
    40  		dst = append(dst, d)
    41  	}
    42  	return
    43  }