Package maps
Package maps defines various functions useful with maps of any type.
This package does not have any special handling for non-reflexive keys
(keys k where k != k), such as floating-point NaNs.
- func All[Map ~map[K]V, K comparable, V any](m Map) iter.Seq2[K, V]
- func Clone[M ~map[K]V, K comparable, V any](m M) M
- func Collect[K comparable, V any](seq iter.Seq2[K, V]) map[K]V
- func Copy[M1 ~map[K]V, M2 ~map[K]V, K comparable, V any](dst M1, src M2)
- func DeleteFunc[M ~map[K]V, K comparable, V any](m M, del func(K, V) bool)
- func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool
- func EqualFunc[M1 ~map[K]V1, M2 ~map[K]V2, K comparable, V1, V2 any](m1 M1, m2 M2, eq func(V1, V2) bool) bool
- func Insert[Map ~map[K]V, K comparable, V any](m Map, seq iter.Seq2[K, V])
- func Keys[Map ~map[K]V, K comparable, V any](m Map) iter.Seq[K]
- func Values[Map ~map[K]V, K comparable, V any](m Map) iter.Seq[V]
Package files
iter.go
maps.go
func All[Map ~map[K]V, K comparable, V any](m Map) iter.Seq2[K, V]
All returns an iterator over key-value pairs from m.
The iteration order is not specified and is not guaranteed
to be the same from one call to the next.
func Clone[M ~map[K]V, K comparable, V any](m M) M
Clone returns a copy of m. This is a shallow clone:
the new keys and values are set using ordinary assignment.
▾ Example
Code:
m1 := map[string]int{
"key": 1,
}
m2 := maps.Clone(m1)
m2["key"] = 100
fmt.Println(m1["key"])
fmt.Println(m2["key"])
m3 := map[string][]int{
"key": {1, 2, 3},
}
m4 := maps.Clone(m3)
fmt.Println(m4["key"][0])
m4["key"][0] = 100
fmt.Println(m3["key"][0])
fmt.Println(m4["key"][0])
Output:
1
100
1
100
100
func Collect[K comparable, V any](seq iter.Seq2[K, V]) map[K]V
Collect collects key-value pairs from seq into a new map
and returns it.
func Copy[M1 ~map[K]V, M2 ~map[K]V, K comparable, V any](dst M1, src M2)
Copy copies all key/value pairs in src adding them to dst.
When a key in src is already present in dst,
the value in dst will be overwritten by the value associated
with the key in src.
▾ Example
Code:
m1 := map[string]int{
"one": 1,
"two": 2,
}
m2 := map[string]int{
"one": 10,
}
maps.Copy(m2, m1)
fmt.Println("m2 is:", m2)
m2["one"] = 100
fmt.Println("m1 is:", m1)
fmt.Println("m2 is:", m2)
m3 := map[string][]int{
"one": {1, 2, 3},
"two": {4, 5, 6},
}
m4 := map[string][]int{
"one": {7, 8, 9},
}
maps.Copy(m4, m3)
fmt.Println("m4 is:", m4)
m4["one"][0] = 100
fmt.Println("m3 is:", m3)
fmt.Println("m4 is:", m4)
Output:
m2 is: map[one:1 two:2]
m1 is: map[one:1 two:2]
m2 is: map[one:100 two:2]
m4 is: map[one:[1 2 3] two:[4 5 6]]
m3 is: map[one:[100 2 3] two:[4 5 6]]
m4 is: map[one:[100 2 3] two:[4 5 6]]
func DeleteFunc[M ~map[K]V, K comparable, V any](m M, del func(K, V) bool)
DeleteFunc deletes any key/value pairs from m for which del returns true.
▾ Example
Code:
m := map[string]int{
"one": 1,
"two": 2,
"three": 3,
"four": 4,
}
maps.DeleteFunc(m, func(k string, v int) bool {
return v%2 != 0
})
fmt.Println(m)
Output:
map[four:4 two:2]
func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool
Equal reports whether two maps contain the same key/value pairs.
Values are compared using ==.
▾ Example
Code:
m1 := map[int]string{
1: "one",
10: "Ten",
1000: "THOUSAND",
}
m2 := map[int]string{
1: "one",
10: "Ten",
1000: "THOUSAND",
}
m3 := map[int]string{
1: "one",
10: "ten",
1000: "thousand",
}
fmt.Println(maps.Equal(m1, m2))
fmt.Println(maps.Equal(m1, m3))
Output:
true
false
func EqualFunc[M1 ~map[K]V1, M2 ~map[K]V2, K comparable, V1, V2 any](m1 M1, m2 M2, eq func(V1, V2) bool) bool
EqualFunc is like Equal, but compares values using eq.
Keys are still compared with ==.
▾ Example
Code:
m1 := map[int]string{
1: "one",
10: "Ten",
1000: "THOUSAND",
}
m2 := map[int][]byte{
1: []byte("One"),
10: []byte("Ten"),
1000: []byte("Thousand"),
}
eq := maps.EqualFunc(m1, m2, func(v1 string, v2 []byte) bool {
return strings.ToLower(v1) == strings.ToLower(string(v2))
})
fmt.Println(eq)
Output:
true
func Insert[Map ~map[K]V, K comparable, V any](m Map, seq iter.Seq2[K, V])
Insert adds the key-value pairs from seq to m.
If a key in seq already exists in m, its value will be overwritten.
func Keys[Map ~map[K]V, K comparable, V any](m Map) iter.Seq[K]
Keys returns an iterator over keys in m.
The iteration order is not specified and is not guaranteed
to be the same from one call to the next.
func Values[Map ~map[K]V, K comparable, V any](m Map) iter.Seq[V]
Values returns an iterator over values in m.
The iteration order is not specified and is not guaranteed
to be the same from one call to the next.