github.com/qiniu/x@v1.11.9/errors/go113.go (about)

     1  //go:build go1.13
     2  // +build go1.13
     3  
     4  /*
     5   Copyright 2022 Qiniu Limited (qiniu.com)
     6  
     7   Licensed under the Apache License, Version 2.0 (the "License");
     8   you may not use this file except in compliance with the License.
     9   You may obtain a copy of the License at
    10  
    11       http://www.apache.org/licenses/LICENSE-2.0
    12  
    13   Unless required by applicable law or agreed to in writing, software
    14   distributed under the License is distributed on an "AS IS" BASIS,
    15   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    16   See the License for the specific language governing permissions and
    17   limitations under the License.
    18  */
    19  
    20  package errors
    21  
    22  import (
    23  	"errors"
    24  )
    25  
    26  // --------------------------------------------------------------------
    27  
    28  // Unwrap returns the result of calling the Unwrap method on err, if err's
    29  // type contains an Unwrap method returning error.
    30  // Otherwise, Unwrap returns nil.
    31  func Unwrap(err error) error {
    32  	return errors.Unwrap(err)
    33  }
    34  
    35  // Is reports whether any error in err's chain matches target.
    36  //
    37  // The chain consists of err itself followed by the sequence of errors obtained by
    38  // repeatedly calling Unwrap.
    39  //
    40  // An error is considered to match a target if it is equal to that target or if
    41  // it implements a method Is(error) bool such that Is(target) returns true.
    42  //
    43  // An error type might provide an Is method so it can be treated as equivalent
    44  // to an existing error. For example, if MyError defines
    45  //
    46  //	func (m MyError) Is(target error) bool { return target == os.ErrExist }
    47  //
    48  // then Is(MyError{}, os.ErrExist) returns true. See syscall.Errno.Is for
    49  // an example in the standard library.
    50  func Is(err, target error) bool {
    51  	return errors.Is(err, target)
    52  }
    53  
    54  // As finds the first error in err's chain that matches target, and if so, sets
    55  // target to that error value and returns true. Otherwise, it returns false.
    56  //
    57  // The chain consists of err itself followed by the sequence of errors obtained by
    58  // repeatedly calling Unwrap.
    59  //
    60  // An error matches target if the error's concrete value is assignable to the value
    61  // pointed to by target, or if the error has a method As(interface{}) bool such that
    62  // As(target) returns true. In the latter case, the As method is responsible for
    63  // setting target.
    64  //
    65  // An error type might provide an As method so it can be treated as if it were a
    66  // a different error type.
    67  //
    68  // As panics if target is not a non-nil pointer to either a type that implements
    69  // error, or to any interface type.
    70  func As(err error, target interface{}) bool {
    71  	return errors.As(err, target)
    72  }
    73  
    74  // --------------------------------------------------------------------