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| -rw-r--r-- | README.md | 31 |
1 files changed, 19 insertions, 12 deletions
@@ -135,10 +135,14 @@ is implemented to act similarly to the built-in Go `map` type. It is implemented as a [Hash-Array Mapped Trie](https://lampwww.epfl.ch/papers/idealhashtrees.pdf). Maps require a `Hasher` to hash keys and check for equality. There are built-in -hasher implementations for most primitive types such as `int`, `uint`, `string`, -and `[]byte` keys. You may pass in a `nil` hasher to `NewMap()` if you are using +hasher implementations for most primitive types such as `int`, `uint`, and +`string` keys. You may pass in a `nil` hasher to `NewMap()` if you are using one of these key types. +Currently `[]byte` keys are not supported since Go doesn't included them in +`constraints.Ordered` unline strings. For now `Ordered` constraint it used even +for `Map` where key order is unimportant but this could be relaxed in the +future. ### Setting map key/value pairs @@ -234,9 +238,9 @@ Builders are invalid after the call to `Map()`. ### Implementing a custom Hasher -If you need to use a key type besides `int`, `uint`, `string`, or `[]byte` then -you'll need to create a custom `Hasher` implementation and pass it to `NewMap()` -on creation. +If you need to use a key type besides `int`, `uint`, or `string` then you'll +need to create a custom `Hasher` implementation and pass it to `NewMap()` on +creation. Hashers are fairly simple. They only need to generate hashes for a given key and check equality given two keys. @@ -259,9 +263,12 @@ Unlike the `Map`, however, keys can be iterated over in-order. It is implemented as a B+tree. Sorted maps require a `Comparer` to sort keys and check for equality. There are -built-in comparer implementations for `int`, `uint`, `string`, and `[]byte` keys. -You may pass a `nil` comparer to `NewSortedMap()` if you are using one of these -key types. +built-in comparer implementations for `int`, `uint`, and `string` keys. You may +pass a `nil` comparer to `NewSortedMap()` if you are using one of these key +types. + +Currently `[]byte` keys are not supported since Go doesn't included them in +`constraints.Ordered` unline strings. The API is identical to the `Map` implementation. The sorted map also has a companion `SortedMapBuilder` for more efficiently building maps. @@ -269,8 +276,8 @@ companion `SortedMapBuilder` for more efficiently building maps. ### Implementing a custom Comparer -If you need to use a key type besides `int`, `uint`, `string`, or `[]byte` -then you'll need to create a custom `Comparer` implementation and pass it to +If you need to use a key type besides `int`, `uint`, or `string` then you'll +need to create a custom `Comparer` implementation and pass it to `NewSortedMap()` on creation. Comparers on have one method—`Compare()`. It works the same as the @@ -283,8 +290,8 @@ type Comparer[K constraints.Ordered] interface { } ``` -Please see the internal `intComparer`, `uintComparer`, `stringComparer`, and -`byteSliceComparer` for examples. +Please see the internal `intComparer`, `uintComparer`, and `stringComparer` for +examples. |