github.com/songzhibin97/go-baseutils@v0.0.2-0.20240302024150-487d8ce9c082/base/bcomparator/comparator.go (about)

     1  package bcomparator
     2  
     3  import (
     4  	"encoding/json"
     5  	"fmt"
     6  	"strings"
     7  
     8  	"github.com/songzhibin97/go-baseutils/base/bmath"
     9  	"github.com/songzhibin97/go-baseutils/base/bternaryexpr"
    10  	"github.com/songzhibin97/go-baseutils/base/btype"
    11  )
    12  
    13  type Comparator[T any] func(a, b T) int
    14  
    15  func (c Comparator[T]) Marshal(t T) ([]byte, error) {
    16  	return json.Marshal(t)
    17  }
    18  
    19  type temporary[T any] struct {
    20  	Key T `json:"key"`
    21  }
    22  
    23  func (c Comparator[T]) Unmarshal(data []byte, v *T) error {
    24  	err := json.Unmarshal(data, v)
    25  	if err != nil {
    26  		switch err.(type) {
    27  		case *json.SyntaxError:
    28  			var temp temporary[T]
    29  			data = []byte(fmt.Sprintf(`{"key": "%s"}`, string(data)))
    30  			err = json.Unmarshal(data, &temp)
    31  			if err != nil {
    32  				return err
    33  			}
    34  			*v = temp.Key
    35  		default:
    36  			return err
    37  		}
    38  	}
    39  	return nil
    40  }
    41  
    42  func OrderedComparator[T btype.Ordered]() Comparator[T] {
    43  	return func(a T, b T) int {
    44  		return bternaryexpr.TernaryExpr[int](a == b, 0, bternaryexpr.TernaryExpr[int](a > b, 1, -1))
    45  	}
    46  }
    47  
    48  func ReverseComparator[T any](comparator Comparator[T]) Comparator[T] {
    49  	return func(a T, b T) int {
    50  		return comparator(a, b) * -1
    51  	}
    52  }
    53  
    54  // ------------------------------------------------ ---------------------------------------------------------------------
    55  
    56  // StringComparator 比较字符串
    57  func StringComparator() Comparator[string] {
    58  	return strings.Compare
    59  }
    60  
    61  // ------------------------------------------------ ---------------------------------------------------------------------
    62  
    63  func IntComparator() Comparator[int] {
    64  	return OrderedComparator[int]()
    65  }
    66  
    67  func Int8Comparator() Comparator[int8] {
    68  	return OrderedComparator[int8]()
    69  }
    70  
    71  func Int16Comparator() Comparator[int16] {
    72  	return OrderedComparator[int16]()
    73  }
    74  
    75  func Int32Comparator() Comparator[int32] {
    76  	return OrderedComparator[int32]()
    77  }
    78  
    79  func Int64Comparator() Comparator[int64] {
    80  	return OrderedComparator[int64]()
    81  }
    82  
    83  // ------------------------------------------------ ---------------------------------------------------------------------
    84  
    85  func UintComparator() Comparator[uint] {
    86  	return OrderedComparator[uint]()
    87  }
    88  
    89  func Uint8Comparator() Comparator[uint8] {
    90  	return OrderedComparator[uint8]()
    91  }
    92  
    93  func Uint16Comparator() Comparator[uint16] {
    94  	return OrderedComparator[uint16]()
    95  }
    96  
    97  func Uint32Comparator() Comparator[uint32] {
    98  	return OrderedComparator[uint32]()
    99  }
   100  
   101  func Uint64Comparator() Comparator[uint64] {
   102  	return OrderedComparator[uint64]()
   103  }
   104  
   105  // ------------------------------------------------ ---------------------------------------------------------------------
   106  
   107  func Float32Comparator() Comparator[float32] {
   108  	return func(a float32, b float32) int {
   109  		return bternaryexpr.TernaryExpr[int](bmath.Abs(float64(a-b)) < 0.0000001, 0, bternaryexpr.TernaryExpr[int](a > b, 1, -1))
   110  	}
   111  }
   112  
   113  func Float64Comparator() Comparator[float64] {
   114  	return func(a float64, b float64) int {
   115  		return bternaryexpr.TernaryExpr[int](bmath.Abs(a-b) < 0.0000001, 0, bternaryexpr.TernaryExpr[int](a > b, 1, -1))
   116  	}
   117  }
   118  
   119  // ------------------------------------------------ ---------------------------------------------------------------------
   120  
   121  // BoolComparator 布尔类型的比较器，默认是让false排在前面
   122  func BoolComparator() Comparator[bool] {
   123  	return func(a bool, b bool) int {
   124  		return bternaryexpr.TernaryExpr[int](a == b, 0, bternaryexpr.TernaryExpr[int](!a && b, -1, 1))
   125  	}
   126  }