rust/src/libcoretest/hash/mod.rs

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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
use std::mem;
use std::hash::{Hash, Hasher, Writer};
use std::default::Default;
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
struct MyHasher {
hash: u64,
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
impl Default for MyHasher {
fn default() -> MyHasher {
MyHasher { hash: 0 }
}
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
impl Writer for MyHasher {
// Most things we'll just add up the bytes.
fn write(&mut self, buf: &[u8]) {
for byte in buf.iter() {
self.hash += *byte as u64;
}
}
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
impl Hasher for MyHasher {
type Output = u64;
fn reset(&mut self) { self.hash = 0; }
fn finish(&self) -> u64 { self.hash }
}
#[test]
fn test_writer_hasher() {
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
fn hash<T: Hash<MyHasher>>(t: &T) -> u64 {
::std::hash::hash::<_, MyHasher>(t)
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&()), 0);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&5u8), 5);
assert_eq!(hash(&5u16), 5);
assert_eq!(hash(&5u32), 5);
assert_eq!(hash(&5u64), 5);
2015-01-31 10:23:42 -06:00
assert_eq!(hash(&5us), 5);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&5i8), 5);
assert_eq!(hash(&5i16), 5);
assert_eq!(hash(&5i32), 5);
assert_eq!(hash(&5i64), 5);
2015-01-31 10:23:42 -06:00
assert_eq!(hash(&5is), 5);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&false), 0);
assert_eq!(hash(&true), 1);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&'a'), 97);
let s: &str = "a";
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(& s), 97 + 0xFF);
// FIXME (#18283) Enable test
//let s: Box<str> = box "a";
//assert_eq!(hasher.hash(& s), 97 + 0xFF);
let cs: &[u8] = &[1u8, 2u8, 3u8];
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(& cs), 9);
let cs: Box<[u8]> = box [1u8, 2u8, 3u8];
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(& cs), 9);
// FIXME (#18248) Add tests for hashing Rc<str> and Rc<[T]>
unsafe {
2015-01-31 10:23:42 -06:00
let ptr: *const i32 = mem::transmute(5us);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&ptr), 5);
}
unsafe {
2015-01-31 10:23:42 -06:00
let ptr: *mut i32 = mem::transmute(5us);
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
assert_eq!(hash(&ptr), 5);
}
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
struct Custom { hash: u64 }
struct CustomHasher { output: u64 }
impl Hasher for CustomHasher {
type Output = u64;
fn reset(&mut self) { self.output = 0; }
fn finish(&self) -> u64 { self.output }
}
impl Default for CustomHasher {
fn default() -> CustomHasher {
CustomHasher { output: 0 }
}
}
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
impl Hash<CustomHasher> for Custom {
fn hash(&self, state: &mut CustomHasher) {
state.output = self.hash;
}
}
#[test]
fn test_custom_state() {
std: Stabilize the std::hash module This commit aims to prepare the `std::hash` module for alpha by formalizing its current interface whileholding off on adding `#[stable]` to the new APIs. The current usage with the `HashMap` and `HashSet` types is also reconciled by separating out composable parts of the design. The primary goal of this slight redesign is to separate the concepts of a hasher's state from a hashing algorithm itself. The primary change of this commit is to separate the `Hasher` trait into a `Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was actually just a factory for various states, but hashing had very little control over how these states were used. Additionally the old `Hasher` trait was actually fairly unrelated to hashing. This commit redesigns the existing `Hasher` trait to match what the notion of a `Hasher` normally implies with the following definition: trait Hasher { type Output; fn reset(&mut self); fn finish(&self) -> Output; } This `Hasher` trait emphasizes that hashing algorithms may produce outputs other than a `u64`, so the output type is made generic. Other than that, however, very little is assumed about a particular hasher. It is left up to implementors to provide specific methods or trait implementations to feed data into a hasher. The corresponding `Hash` trait becomes: trait Hash<H: Hasher> { fn hash(&self, &mut H); } The old default of `SipState` was removed from this trait as it's not something that we're willing to stabilize until the end of time, but the type parameter is always required to implement `Hasher`. Note that the type parameter `H` remains on the trait to enable multidispatch for specialization of hashing for particular hashers. Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is simply used as part `derive` and the implementations for all primitive types. With these definitions, the old `Hasher` trait is realized as a new `HashState` trait in the `collections::hash_state` module as an unstable addition for now. The current definition looks like: trait HashState { type Hasher: Hasher; fn hasher(&self) -> Hasher; } The purpose of this trait is to emphasize that the one piece of functionality for implementors is that new instances of `Hasher` can be created. This conceptually represents the two keys from which more instances of a `SipHasher` can be created, and a `HashState` is what's stored in a `HashMap`, not a `Hasher`. Implementors of custom hash algorithms should implement the `Hasher` trait, and only hash algorithms intended for use in hash maps need to implement or worry about the `HashState` trait. The entire module and `HashState` infrastructure remains `#[unstable]` due to it being recently redesigned, but some other stability decision made for the `std::hash` module are: * The `Writer` trait remains `#[experimental]` as it's intended to be replaced with an `io::Writer` (more details soon). * The top-level `hash` function is `#[unstable]` as it is intended to be generic over the hashing algorithm instead of hardwired to `SipHasher` * The inner `sip` module is now private as its one export, `SipHasher` is reexported in the `hash` module. And finally, a few changes were made to the default parameters on `HashMap`. * The `RandomSipHasher` default type parameter was renamed to `RandomState`. This renaming emphasizes that it is not a hasher, but rather just state to generate hashers. It also moves away from the name "sip" as it may not always be implemented as `SipHasher`. This type lives in the `std::collections::hash_map` module as `#[unstable]` * The associated `Hasher` type of `RandomState` is creatively called... `Hasher`! This concrete structure lives next to `RandomState` as an implemenation of the "default hashing algorithm" used for a `HashMap`. Under the hood this is currently implemented as `SipHasher`, but it draws an explicit interface for now and allows us to modify the implementation over time if necessary. There are many breaking changes outlined above, and as a result this commit is a: [breaking-change]
2014-12-09 14:37:23 -06:00
fn hash<T: Hash<CustomHasher>>(t: &T) -> u64 {
::std::hash::hash::<_, CustomHasher>(t)
}
assert_eq!(hash(&Custom { hash: 5 }), 5);
}