github.com/isyscore/isc-gobase@v1.5.3-0.20231218061332-cbc7451899e9/isc/find.go (about)

     1  package isc
     2  
     3  import "reflect"
     4  
     5  func Find[T any](list []T, f func(T) bool) *T {
     6  	var n *T = nil
     7  	for _, e := range list {
     8  		if f(e) {
     9  			n = &e
    10  			break
    11  		}
    12  	}
    13  	return n
    14  }
    15  
    16  func FindLast[T any](list []T, f func(T) bool) *T {
    17  	var n *T = nil
    18  	for i := len(list) - 1; i >= 0; i-- {
    19  		e := list[i]
    20  		if f(e) {
    21  			n = &e
    22  			break
    23  		}
    24  	}
    25  	return n
    26  }
    27  
    28  func First[T any](list []T) T {
    29  	return list[0]
    30  }
    31  
    32  func Last[T any](list []T) T {
    33  	return list[len(list)-1]
    34  }
    35  
    36  func FirstOrNull[T any](list []T) *T {
    37  	var n *T = nil
    38  	if len(list) > 0 {
    39  		n = &list[0]
    40  	}
    41  	return n
    42  }
    43  
    44  func LastOrNull[T any](list []T) *T {
    45  	var n *T = nil
    46  	if len(list) > 0 {
    47  		n = &list[len(list)-1]
    48  	}
    49  	return n
    50  }
    51  
    52  //IndexOf 判断元素item是否在分片中，示例res := IndexOf[int](list,item),使用时须指明类型
    53  func IndexOf[T any](list []T, item T) int {
    54  	idx := -1
    55  	for i, e := range list {
    56  		if reflect.DeepEqual(e, item) {
    57  			idx = i
    58  			break
    59  		}
    60  	}
    61  	return idx
    62  }
    63  
    64  func LastIndexOf[T any](list []T, item T) int {
    65  	idx := -1
    66  	for i := len(list) - 1; i >= 0; i-- {
    67  		e := list[i]
    68  		if reflect.DeepEqual(e, item) {
    69  			idx = i
    70  			break
    71  		}
    72  	}
    73  	return idx
    74  }
    75  
    76  func IndexOfCondition[T any](list []T, f func(T) bool) int {
    77  	idx := -1
    78  	for i, e := range list {
    79  		if f(e) {
    80  			idx = i
    81  			break
    82  		}
    83  	}
    84  	return idx
    85  }
    86  
    87  func LastIndexOfCondition[T any](list []T, f func(T) bool) int {
    88  	idx := -1
    89  	for i := len(list) - 1; i >= 0; i-- {
    90  		e := list[i]
    91  		if f(e) {
    92  			idx = i
    93  			break
    94  		}
    95  	}
    96  	return idx
    97  }