Source file src/golang.org/x/xerrors/example_FormatError_test.go

Documentation: golang.org/x/xerrors

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package xerrors_test
     6  
     7  import (
     8  	"fmt"
     9  
    10  	"golang.org/x/xerrors"
    11  )
    12  
    13  type MyError2 struct {
    14  	Message string
    15  	frame   xerrors.Frame
    16  }
    17  
    18  func (m *MyError2) Error() string {
    19  	return m.Message
    20  }
    21  
    22  func (m *MyError2) Format(f fmt.State, c rune) { // implements fmt.Formatter
    23  	xerrors.FormatError(m, f, c)
    24  }
    25  
    26  func (m *MyError2) FormatError(p xerrors.Printer) error { // implements xerrors.Formatter
    27  	p.Print(m.Message)
    28  	if p.Detail() {
    29  		m.frame.Format(p)
    30  	}
    31  	return nil
    32  }
    33  
    34  func ExampleFormatError() {
    35  	err := &MyError2{Message: "oops", frame: xerrors.Caller(1)}
    36  	fmt.Printf("%v\n", err)
    37  	fmt.Println()
    38  	fmt.Printf("%+v\n", err)
    39  }
    40  

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