github.com/kaydxh/golang@v0.0.131/go/net/resolver/build_option.go (about)

     1  /*
     2   *Copyright (c) 2022, kaydxh
     3   *
     4   *Permission is hereby granted, free of charge, to any person obtaining a copy
     5   *of this software and associated documentation files (the "Software"), to deal
     6   *in the Software without restriction, including without limitation the rights
     7   *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     8   *copies of the Software, and to permit persons to whom the Software is
     9   *furnished to do so, subject to the following conditions:
    10   *
    11   *The above copyright notice and this permission notice shall be included in all
    12   *copies or substantial portions of the Software.
    13   *
    14   *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    15   *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    16   *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    17   *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    18   *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    19   *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    20   *SOFTWARE.
    21   */
    22  package resolver
    23  
    24  // A ResolverBuildOption sets options.
    25  type ResolverBuildOption interface {
    26  	apply(*ResolverBuildOptions)
    27  }
    28  
    29  // EmptyResolverBuildUrlOption does not alter the ResolverBuilduration. It can be embedded
    30  // in another structure to build custom options.
    31  //
    32  // This API is EXPERIMENTAL.
    33  type EmptyResolverBuildOption struct{}
    34  
    35  func (EmptyResolverBuildOption) apply(*ResolverBuildOptions) {}
    36  
    37  // ResolverBuildOptionFunc wraps a function that modifies ResolverBuildOptions into an
    38  // implementation of the ResolverBuildOption interface.
    39  type ResolverBuildOptionFunc func(*ResolverBuildOptions)
    40  
    41  func (f ResolverBuildOptionFunc) apply(do *ResolverBuildOptions) {
    42  	f(do)
    43  }
    44  
    45  // sample code for option, default for nothing to change
    46  func _ResolverBuildOptionWithDefault() ResolverBuildOption {
    47  	return ResolverBuildOptionFunc(func(*ResolverBuildOptions) {
    48  		// nothing to change
    49  	})
    50  }
    51  func (o *ResolverBuildOptions) ApplyOptions(options ...ResolverBuildOption) *ResolverBuildOptions {
    52  	for _, opt := range options {
    53  		if opt == nil {
    54  			continue
    55  		}
    56  		opt.apply(o)
    57  	}
    58  	return o
    59  }