enumstringer.go

Documentation: github.com/gogo/protobuf/plugin/enumstringer

     1  // Protocol Buffers for Go with Gadgets
     2  //
     3  // Copyright (c) 2013, The GoGo Authors. All rights reserved.
     4  // http://github.com/gogo/protobuf
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    13  // copyright notice, this list of conditions and the following disclaimer
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    26  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    27  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    28  
    29  /*
    30  The enumstringer (experimental) plugin generates a String method for each enum.
    31  
    32  It is enabled by the following extensions:
    33  
    34    - enum_stringer
    35    - enum_stringer_all
    36  
    37  This package is subject to change.
    38  
    39  */
    40  package enumstringer
    41  
    42  import (
    43  	"github.com/gogo/protobuf/gogoproto"
    44  	"github.com/gogo/protobuf/protoc-gen-gogo/generator"
    45  )
    46  
    47  type enumstringer struct {
    48  	*generator.Generator
    49  	generator.PluginImports
    50  	atleastOne bool
    51  	localName  string
    52  }
    53  
    54  func NewEnumStringer() *enumstringer {
    55  	return &enumstringer{}
    56  }
    57  
    58  func (p *enumstringer) Name() string {
    59  	return "enumstringer"
    60  }
    61  
    62  func (p *enumstringer) Init(g *generator.Generator) {
    63  	p.Generator = g
    64  }
    65  
    66  func (p *enumstringer) Generate(file *generator.FileDescriptor) {
    67  	p.PluginImports = generator.NewPluginImports(p.Generator)
    68  	p.atleastOne = false
    69  
    70  	p.localName = generator.FileName(file)
    71  
    72  	strconvPkg := p.NewImport("strconv")
    73  
    74  	for _, enum := range file.Enums() {
    75  		if !gogoproto.IsEnumStringer(file.FileDescriptorProto, enum.EnumDescriptorProto) {
    76  			continue
    77  		}
    78  		if gogoproto.IsGoEnumStringer(file.FileDescriptorProto, enum.EnumDescriptorProto) {
    79  			panic("Go enum stringer conflicts with new enumstringer plugin: please use gogoproto.goproto_enum_stringer or gogoproto.goproto_enum_string_all and set it to false")
    80  		}
    81  		p.atleastOne = true
    82  		ccTypeName := generator.CamelCaseSlice(enum.TypeName())
    83  		p.P("func (x ", ccTypeName, ") String() string {")
    84  		p.In()
    85  		p.P(`s, ok := `, ccTypeName, `_name[int32(x)]`)
    86  		p.P(`if ok {`)
    87  		p.In()
    88  		p.P(`return s`)
    89  		p.Out()
    90  		p.P(`}`)
    91  		p.P(`return `, strconvPkg.Use(), `.Itoa(int(x))`)
    92  		p.Out()
    93  		p.P(`}`)
    94  	}
    95  
    96  	if !p.atleastOne {
    97  		return
    98  	}
    99  
   100  }
   101  
   102  func init() {
   103  	generator.RegisterPlugin(NewEnumStringer())
   104  }
   105
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