go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/flag/fieldslice.go (about)

     1  // Copyright 2018 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package flag
    16  
    17  import (
    18  	"flag"
    19  	"strings"
    20  
    21  	"google.golang.org/api/googleapi"
    22  )
    23  
    24  // fieldSliceFlag is a flag.Getter implementation representing a []googleapi.Field.
    25  type fieldSliceFlag []googleapi.Field
    26  
    27  // String returns a comma-separated string representation of the flag values.
    28  func (f fieldSliceFlag) String() string {
    29  	r := make([]string, len(f))
    30  	for i, s := range f {
    31  		r[i] = string(s)
    32  	}
    33  	return strings.Join(r, ", ")
    34  }
    35  
    36  // Set records seeing a flag value.
    37  func (f *fieldSliceFlag) Set(val string) error {
    38  	*f = append(*f, googleapi.Field(val))
    39  	return nil
    40  }
    41  
    42  // Get retrieves the flag value.
    43  func (f fieldSliceFlag) Get() any {
    44  	return []googleapi.Field(f)
    45  }
    46  
    47  // FieldSlice returns a flag.Getter which reads flags into the given []googleapi.Field pointer.
    48  func FieldSlice(f *[]googleapi.Field) flag.Getter {
    49  	return (*fieldSliceFlag)(f)
    50  }