github.com/mymmsc/gox@v1.3.33/util/arraylist/enumerable.go (about)

     1  // Copyright (c) 2015, Emir Pasic. 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 arraylist
     6  
     7  import (
     8  	"github.com/mymmsc/gox/util"
     9  )
    10  
    11  func assertEnumerableImplementation() {
    12  	var _ util.EnumerableWithIndex = (*List)(nil)
    13  }
    14  
    15  // Each calls the given function once for each element, passing that element's index and value.
    16  func (list *List) Each(f func(index int, value interface{})) {
    17  	iterator := list.Iterator()
    18  	for iterator.Next() {
    19  		f(iterator.Index(), iterator.Value())
    20  	}
    21  }
    22  
    23  // Map invokes the given function once for each element and returns a
    24  // container containing the values returned by the given function.
    25  func (list *List) Map(f func(index int, value interface{}) interface{}) *List {
    26  	newList := &List{}
    27  	iterator := list.Iterator()
    28  	for iterator.Next() {
    29  		newList.Add(f(iterator.Index(), iterator.Value()))
    30  	}
    31  	return newList
    32  }
    33  
    34  // Select returns a new container containing all elements for which the given function returns a true value.
    35  func (list *List) Select(f func(index int, value interface{}) bool) *List {
    36  	newList := &List{}
    37  	iterator := list.Iterator()
    38  	for iterator.Next() {
    39  		if f(iterator.Index(), iterator.Value()) {
    40  			newList.Add(iterator.Value())
    41  		}
    42  	}
    43  	return newList
    44  }
    45  
    46  // Any passes each element of the collection to the given function and
    47  // returns true if the function ever returns true for any element.
    48  func (list *List) Any(f func(index int, value interface{}) bool) bool {
    49  	iterator := list.Iterator()
    50  	for iterator.Next() {
    51  		if f(iterator.Index(), iterator.Value()) {
    52  			return true
    53  		}
    54  	}
    55  	return false
    56  }
    57  
    58  // All passes each element of the collection to the given function and
    59  // returns true if the function returns true for all elements.
    60  func (list *List) All(f func(index int, value interface{}) bool) bool {
    61  	iterator := list.Iterator()
    62  	for iterator.Next() {
    63  		if !f(iterator.Index(), iterator.Value()) {
    64  			return false
    65  		}
    66  	}
    67  	return true
    68  }
    69  
    70  // Find passes each element of the container to the given function and returns
    71  // the first (index,value) for which the function is true or -1,nil otherwise
    72  // if no element matches the criteria.
    73  func (list *List) Find(f func(index int, value interface{}) bool) (int, interface{}) {
    74  	iterator := list.Iterator()
    75  	for iterator.Next() {
    76  		if f(iterator.Index(), iterator.Value()) {
    77  			return iterator.Index(), iterator.Value()
    78  		}
    79  	}
    80  	return -1, nil
    81  }