Tree - Methods

tip

The following is a list of commonly used methods; documentation updates may lag behind new features in the code. For more methods and examples, please refer to the code documentation: https://pkg.go.dev/github.com/gogf/gf/v2/container/gtree

NewBTree

• Description: NewBTree creates a BTree using m (maximum number of child nodes) and a custom comparator. The safe parameter specifies whether to use a concurrency-safe tree, with a default value of false.

• Note: The m parameter must be greater than or equal to 3, otherwise it will panic.

• Format:

NewBTree(m int, comparator func(v1, v2 interface{}) int, safe ...bool) *BTree

• Example:

func ExampleNewBTree() {
      bTree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          bTree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }
      fmt.Println(bTree.Map())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
}

NewBTreeFrom

• Description: NewBTreeFrom creates a BTree using m (maximum number of child nodes), a custom comparator, and data of type map[interface{}]interface{}. The safe parameter specifies whether to use a concurrency-safe tree, with a default value of false.

• Note: The m parameter must be greater than or equal to 3, otherwise it will panic.

• Format:

NewBTreeFrom(m int, comparator func(v1, v2 interface{}) int, data map[interface{}]interface{}, safe ...bool) *BTree

• Example:

func ExampleNewBTreeFrom() {
      bTree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          bTree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      otherBTree := gtree.NewBTreeFrom(3, gutil.ComparatorString, bTree.Map())
      fmt.Println(otherBTree.Map())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
}

Clone

• Description: Clone returns a new BTree, which is a copy of the current tree.

• Format:

Clone() *BTree

• Example:

func ExampleBTree_Clone() {
      b := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          b.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      tree := b.Clone()

      fmt.Println(tree.Map())
      fmt.Println(tree.Size())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
      // 6
}

Set

• Description: Set sets the key/value for the tree.

• Format:

Set(key interface{}, value interface{})

• Example:

func ExampleBTree_Set() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Map())
      fmt.Println(tree.Size())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
      // 6
}

Sets

• Description: Sets sets key/value for the tree in batches.

• Format:

Sets(data map[interface{}]interface{})

• Example:

func ExampleBTree_Sets() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)

      tree.Sets(map[interface{}]interface{}{
          "key1": "val1",
          "key2": "val2",
      })

      fmt.Println(tree.Map())
      fmt.Println(tree.Size())

      // Output:
      // map[key1:val1 key2:val2]
      // 2
}

Get

• Description: Get returns the value value corresponding to the parameter key. If key does not exist, it returns Nil.

• Format:

Get(key interface{}) (value interface{})

• Example:

func ExampleBTree_Get() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Get("key1"))
      fmt.Println(tree.Get("key10"))

      // Output:
      // val1
      // <nil>
}

GetOrSet

• Description: GetOrSet returns value if key exists; if key does not exist, it sets the key-value with key and value, then returns the value.

• Format:

GetOrSet(key interface{}, value interface{}) interface{}

• Example:

func ExampleBTree_GetOrSet() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetOrSet("key1", "newVal1"))
      fmt.Println(tree.GetOrSet("key6", "val6"))

      // Output:
      // val1
      // val6
}

GetOrSetFunc

• Description: GetOrSetFunc returns value if key exists; if key does not exist, it sets the key-value with key and the return value of func f, then returns the value.

• Format:

GetOrSetFunc(key interface{}, f func() interface{}) interface{}

• Example:

func ExampleBTree_GetOrSetFunc() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetOrSetFunc("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.GetOrSetFunc("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // val1
      // val6
}

GetOrSetFuncLock

• Description: GetOrSetFunc returns value if key exists; if key does not exist, it sets the key-value with key and the return value of func f, then returns the value.

• Note: The difference between GetOrSetFuncLock and GetOrSetFunc is that it executes the function f in a write lock.

• Format:

GetOrSetFuncLock(key interface{}, f func() interface{}) interface{}

• Example:

func ExampleBTree_GetOrSetFuncLock() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetOrSetFuncLock("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.GetOrSetFuncLock("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // val1
      // val6
}

GetVar

• Description: GetVar searches and returns the key value corresponding to the key name key, the type is *gvar.Var.

• Note: The returned gvar.Var is not concurrent safe.

• Format:

GetVar(key interface{}) *gvar.Var

• Example:

func ExampleBTree_GetVar() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetVar("key1").String())

      // Output:
      // val1
}

GetVarOrSet

• Description: GetVarOrSet returns the result of GetOrSet, the type is *gvar.Var.

• Note: The returned gvar.Var is not concurrent safe.

• Format:

GetVarOrSet(key interface{}, value interface{}) *gvar.Var

• Example:

func ExampleBTree_GetVarOrSet() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetVarOrSet("key1", "newVal1"))
      fmt.Println(tree.GetVarOrSet("key6", "val6"))

      // Output:
      // val1
      // val6
}

GetVarOrSetFunc

• Description: GetVarOrSetFunc returns the result of GetOrSetFunc, the type is *gvar.Var.
• Note: The returned gvar.Var is not concurrent safe.
• Format:

GetVarOrSetFunc(key interface{}, f func() interface{}) *gvar.Var

• Example:

func ExampleBTree_GetVarOrSetFunc() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetVarOrSetFunc("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.GetVarOrSetFunc("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // val1
      // val6
}

GetVarOrSetFuncLock

• Description: GetVarOrSetFuncLock returns the result of GetOrSetFuncLock, the type is *gvar.Var.

• Note: The returned gvar.Var is not concurrent safe.

• Format:

GetVarOrSetFuncLock(key interface{}, f func() interface{}) *gvar.Var

• Example:

func ExampleBTree_GetVarOrSetFuncLock() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.GetVarOrSetFuncLock("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.GetVarOrSetFuncLock("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // val1
      // val6
}

SetIfNotExist

• Description: If key does not exist, SetIfNotExist sets the key-value pair key/value for the map and returns true. If key exists, it returns false, and value will be ignored.

• Format:

SetIfNotExist(key interface{}, value interface{}) bool

• Example:

func ExampleBTree_SetIfNotExist() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.SetIfNotExist("key1", "newVal1"))
      fmt.Println(tree.SetIfNotExist("key6", "val6"))

      // Output:
      // false
      // true
}

SetIfNotExistFunc

• Description: If key does not exist, SetIfNotExistFunc sets the value to the return value of the function f and returns true. If key exists, it returns false, and value will be ignored.

• Format:

SetIfNotExistFunc(key interface{}, f func() interface{}) bool

• Example:

func ExampleBTree_SetIfNotExistFunc() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.SetIfNotExistFunc("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.SetIfNotExistFunc("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // false
      // true
}

SetIfNotExistFuncLock

• Description: If key does not exist, SetIfNotExistFunc sets the value to the return value of func c, then returns true. If key exists, it returns false, and value will be ignored.

• The difference between SetIfNotExistFuncLock and SetIfNotExistFunc is that it executes the function f within mutex.Lock.

• Format:

SetIfNotExistFuncLock(key interface{}, f func() interface{}) bool

• Example:

func ExampleBTree_SetIfNotExistFuncLock() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.SetIfNotExistFuncLock("key1", func() interface{} {
          return "newVal1"
      }))
      fmt.Println(tree.SetIfNotExistFuncLock("key6", func() interface{} {
          return "val6"
      }))

      // Output:
      // false
      // true
}

Contains

• Description: Contains checks if key exists in the tree. If key exists, it returns true; otherwise, it returns false.

• Format:

Contains(key interface{}) bool

• Example:

func ExampleBTree_Contains() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Contains("key1"))
      fmt.Println(tree.Contains("key6"))

      // Output:
      // true
      // false
}

Remove

• Description: Delete the value from tree according to the given key and return this deleted value.

• Format:

Remove(key interface{}) (value interface{})

• Example:

func ExampleBTree_Remove() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Remove("key1"))
      fmt.Println(tree.Remove("key6"))
      fmt.Println(tree.Map())

      // Output:
      // val1
      // <nil>
      // map[key0:val0 key2:val2 key3:val3 key4:val4 key5:val5]
}

Removes

• Description: Removes deletes value of tree in batches according to the given key.

• Format:

Removes(keys []interface{})

• Example:

func ExampleBTree_Removes() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      removeKeys := make([]interface{}, 2)
      removeKeys = append(removeKeys, "key1")
      removeKeys = append(removeKeys, "key6")

      tree.Removes(removeKeys)

      fmt.Println(tree.Map())

      // Output:
      // map[key0:val0 key2:val2 key3:val3 key4:val4 key5:val5]
}

IsEmpty

• Description: IsEmpty checks if tree is empty. If tree is empty, it returns true; otherwise, it returns false.

• Format:

IsEmpty() bool

• Example:

func ExampleBTree_IsEmpty() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)

      fmt.Println(tree.IsEmpty())

      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.IsEmpty())

      // Output:
      // true
      // false
}

Size

• Description: Size returns the size of the tree.

• Format:

Size() int

• Example:

func ExampleBTree_Size() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)

      fmt.Println(tree.Size())

      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Size())

      // Output:
      // 0
      // 6
}

Keys

• Description: Keys returns all keys in ascending order.

• Format:

Keys() []interface{}

• Example:

func ExampleBTree_Keys() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 6; i > 0; i-- {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Keys())

      // Output:
      // [key1 key2 key3 key4 key5 key6]
}

Values

• Description: Values returns all values in ascending order of key.

• Format:

Values() []interface{}

• Example:

func ExampleBTree_Values() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 6; i > 0; i-- {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Values())

      // Output:
      // [val1 val2 val3 val4 val5 val6]
}

Map

• Description: Map returns all key/value pairs in the form of a map.

• Format:

Map() map[interface{}]interface{}

• Example:

func ExampleBTree_Map() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Map())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
}

MapStrAny

• Description: MapStrAny returns all key/value pairs in the form of map[string]interface{}.

• Format:

MapStrAny() map[string]interface{}

• Example:

func ExampleBTree_MapStrAny() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set(1000+i, "val"+gconv.String(i))
      }

      fmt.Println(tree.MapStrAny())

      // Output:
      // map[1000:val0 1001:val1 1002:val2 1003:val3 1004:val4 1005:val5]
}

Clear

• Description: Clear deletes all data in the tree.

• Format:

Clear()

• Example:

func ExampleBTree_Clear() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set(1000+i, "val"+gconv.String(i))
      }
      fmt.Println(tree.Size())

      tree.Clear()
      fmt.Println(tree.Size())

      // Output:
      // 6
      // 0
}

Replace

• Description: Replace replaces the key/value in the tree with data of type map[interface{}]interface{}.

• Format:

Replace(data map[interface{}]interface{})

• Example:

func ExampleBTree_Replace() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Map())

      data := map[interface{}]interface{}{
          "newKey0": "newVal0",
          "newKey1": "newVal1",
          "newKey2": "newVal2",
      }

      tree.Replace(data)

      fmt.Println(tree.Map())

      // Output:
      // map[key0:val0 key1:val1 key2:val2 key3:val3 key4:val4 key5:val5]
      // map[newKey0:newVal0 newKey1:newVal1 newKey2:newVal2]
}

Height

• Description: Height returns the height of the tree.

• Format:

Height() int

• Example:

func ExampleBTree_Height() {
      tree := gtree.NewBTree(3, gutil.ComparatorInt)
      for i := 0; i < 100; i++ {
          tree.Set(i, i)
      }
      fmt.Println(tree.Height())

      // Output:
      // 6
}

Left

• Description: Left returns the leftmost (smallest) node of type *BTreeEntry, or nil if the tree is empty.

• Format:

Left() *BTreeEntry

• Example:

func ExampleBTree_Left() {
      tree := gtree.NewBTree(3, gutil.ComparatorInt)
      for i := 1; i < 100; i++ {
          tree.Set(i, i)
      }
      fmt.Println(tree.Left().Key, tree.Left().Value)

      emptyTree := gtree.NewBTree(3, gutil.ComparatorInt)
      fmt.Println(emptyTree.Left())

      // Output:
      // 1 1
      // <nil>
}

Right

• Description: Right returns the rightmost (largest) node of type *BTreeEntry, or nil if the tree is empty.

• Format:

Right() *BTreeEntry

• Example:

func ExampleBTree_Right() {
      tree := gtree.NewBTree(3, gutil.ComparatorInt)
      for i := 1; i < 100; i++ {
          tree.Set(i, i)
      }
      fmt.Println(tree.Right().Key, tree.Right().Value)

      emptyTree := gtree.NewBTree(3, gutil.ComparatorInt)
      fmt.Println(emptyTree.Left())

      // Output:
      // 99 99
      // <nil>
}

String

• Description: String returns a display (for debugging) of the node in the tree.

• Format:

String() string

• Example:

func ExampleBTree_String() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.String())

      // Output:
      // key0
      // key1
      //     key2
      // key3
      //     key4
      //     key5
}

Search

• Description: Search searches the tree using the parameter key. If the key is found, it returns its corresponding key-value and returns the parameter found as true, otherwise false.

• Format:

Search(key interface{}) (value interface{}, found bool)

• Example:

func ExampleBTree_Search() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      fmt.Println(tree.Search("key0"))
      fmt.Println(tree.Search("key6"))

      // Output:
      // val0 true
      // <nil> false
}

Print

• Description: Print prints the tree to standard output.

• Format:

Print()

• Example:

func ExampleBTree_Print() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      tree.Print()

      // Output:
      // key0
      // key1
      //     key2
      // key3
      //     key4
      //     key5
}

Iterator

• Description: Iterator is equivalent to IteratorAsc.

• Format:

Iterator(f func(key, value interface{}) bool)

• Example:

func ExampleBTree_Iterator() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 10; i++ {
          tree.Set(i, 10-i)
      }

      var totalKey, totalValue int
      tree.Iterator(func(key, value interface{}) bool {
          totalKey += key.(int)
          totalValue += value.(int)

          return totalValue < 20
      })

      fmt.Println("totalKey:", totalKey)
      fmt.Println("totalValue:", totalValue)

      // Output:
      // totalKey: 3
      // totalValue: 27
}

IteratorFrom

• Description: IteratorFrom is equivalent to IteratorAscFrom.

• Format:

IteratorFrom(key interface{}, match bool, f func(key, value interface{}) bool)

• Example:

func ExampleBTree_IteratorFrom() {
      m := make(map[interface{}]interface{})
      for i := 1; i <= 5; i++ {
          m[i] = i * 10
      }
      tree := gtree.NewBTreeFrom(3, gutil.ComparatorInt, m)

      tree.IteratorFrom(1, true, func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 1 , value: 10
      // key: 2 , value: 20
      // key: 3 , value: 30
      // key: 4 , value: 40
      // key: 5 , value: 50
}

IteratorAsc

• Description: IteratorAsc iterates over the tree in ascending order using a custom callback function f in read-only mode. If f returns true, it continues iterating; if it returns false, it stops.

• Format:

IteratorAsc(f func(key, value interface{}) bool)

• Example:

func ExampleBTree_IteratorAsc() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 10; i++ {
          tree.Set(i, 10-i)
      }

      tree.IteratorAsc(func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 0 , value: 10
      // key: 1 , value: 9
      // key: 2 , value: 8
      // key: 3 , value: 7
      // key: 4 , value: 6
      // key: 5 , value: 5
      // key: 6 , value: 4
      // key: 7 , value: 3
      // key: 8 , value: 2
      // key: 9 , value: 1
}

IteratorAscFrom

• Description: IteratorAscFrom iterates over the tree in ascending order using a custom callback function f in read-only mode. The parameter key specifies from which key to start iterating. When match is true, iteration starts from the complete match of key; otherwise, iteration uses index searching. If f returns true, it continues iterating; if it returns false, it stops.

• Format:

IteratorAscFrom(key interface{}, match bool, f func(key, value interface{}) bool)

• Example:

func ExampleBTree_IteratorAscFrom_Normal() {
      m := make(map[interface{}]interface{})
      for i := 1; i <= 5; i++ {
          m[i] = i * 10
      }
      tree := gtree.NewBTreeFrom(3, gutil.ComparatorInt, m)

      tree.IteratorAscFrom(1, true, func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 1 , value: 10
      // key: 2 , value: 20
      // key: 3 , value: 30
      // key: 4 , value: 40
      // key: 5 , value: 50
}
``` ```
func ExampleBTree_IteratorAscFrom_NoExistKey() {
      m := make(map[interface{}]interface{})
      for i := 1; i <= 5; i++ {
          m[i] = i * 10
      }
      tree := gtree.NewBTreeFrom(3, gutil.ComparatorInt, m)

      tree.IteratorAscFrom(0, true, func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
}
``` ```
func ExampleBTree_IteratorAscFrom_NoExistKeyAndMatchFalse() {
      m := make(map[interface{}]interface{})
      for i := 1; i <= 5; i++ {
          m[i] = i * 10
      }
      tree := gtree.NewBTreeFrom(3, gutil.ComparatorInt, m)

      tree.IteratorAscFrom(0, false, func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 1 , value: 10
      // key: 2 , value: 20
      // key: 3 , value: 30
      // key: 4 , value: 40
      // key: 5 , value: 50
}

IteratorDesc

• Description: IteratorDesc iterates over the tree in descending order using a custom callback function f in read-only mode. If f returns true, it continues iterating; if it returns false, it stops.

• Format:

IteratorDesc(f func(key, value interface{}) bool)

• Example:

func ExampleBTree_IteratorDesc() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 10; i++ {
          tree.Set(i, 10-i)
      }

      tree.IteratorDesc(func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 9 , value: 1
      // key: 8 , value: 2
      // key: 7 , value: 3
      // key: 6 , value: 4
      // key: 5 , value: 5
      // key: 4 , value: 6
      // key: 3 , value: 7
      // key: 2 , value: 8
      // key: 1 , value: 9
      // key: 0 , value: 10
}

IteratorDescFrom

• Description: IteratorDescFrom iterates over the tree in descending order using a custom callback function f in read-only mode. The parameter key specifies from which key to start iterating. When match is true, iteration starts from the complete match of key; otherwise, iteration uses index searching. If f returns true, it continues iterating; if it returns false, it stops.

• Format:

IteratorDescFrom(key interface{}, match bool, f func(key, value interface{}) bool)

• Example:

func ExampleBTree_IteratorDescFrom() {
      m := make(map[interface{}]interface{})
      for i := 1; i <= 5; i++ {
          m[i] = i * 10
      }
      tree := gtree.NewBTreeFrom(3, gutil.ComparatorInt, m)

      tree.IteratorDescFrom(5, true, func(key, value interface{}) bool {
          fmt.Println("key:", key, ", value:", value)
          return true
      })

      // Output:
      // key: 5 , value: 50
      // key: 4 , value: 40
      // key: 3 , value: 30
      // key: 2 , value: 20
      // key: 1 , value: 10
}

MarshalJson

• Description: MarshalJSON implements the json.Marshal interface.

• Format:

MarshalJSON() ([]byte, error)

• Example:

func ExampleBTree_MarshalJSON() {
      tree := gtree.NewBTree(3, gutil.ComparatorString)
      for i := 0; i < 6; i++ {
          tree.Set("key"+gconv.String(i), "val"+gconv.String(i))
      }

      bytes, err := json.Marshal(tree)
      if err == nil {
          fmt.Println(gconv.String(bytes))
      }

      // Output:
      // {"key0":"val0","key1":"val1","key2":"val2","key3":"val3","key4":"val4","key5":"val5"}
}