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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/rust/rust_decimal/README.md | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/rust_decimal/README.md')
-rw-r--r-- | third_party/rust/rust_decimal/README.md | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/third_party/rust/rust_decimal/README.md b/third_party/rust/rust_decimal/README.md new file mode 100644 index 0000000000..7a7a6b88d8 --- /dev/null +++ b/third_party/rust/rust_decimal/README.md @@ -0,0 +1,302 @@ +# Decimal   [![Build Status]][actions] [![Latest Version]][crates.io] [![Docs Badge]][docs] + +[Build Status]: https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Fpaupino%2Frust-decimal%2Fbadge&label=build&logo=none +[actions]: https://actions-badge.atrox.dev/paupino/rust-decimal/goto +[Latest Version]: https://img.shields.io/crates/v/rust-decimal.svg +[crates.io]: https://crates.io/crates/rust-decimal +[Docs Badge]: https://docs.rs/rust_decimal/badge.svg +[docs]: https://docs.rs/rust_decimal + +A Decimal number implementation written in pure Rust suitable for financial calculations that require significant integral and fractional digits with no round-off errors. + +The binary representation consists of a 96 bit integer number, a scaling factor used to specify the decimal fraction and a 1 bit sign. Because of this representation, trailing zeros are preserved and may be exposed when in string form. These can be truncated using the `normalize` or `round_dp` functions. + +## Installing + +Using [`cargo-edit`](https://crates.io/crates/cargo-edit): + +```sh +$ cargo add rust_decimal +``` + +In addition, if you would like to use the optimized macro for convenient creation of decimals: + +```sh +$ cargo add rust_decimal_macros +``` + +Alternatively, you can edit your `Cargo.toml` directly and run `cargo update`: + +```toml +[dependencies] +rust_decimal = "1.27" +rust_decimal_macros = "1.27" +``` + +## Usage + +Decimal numbers can be created in a few distinct ways. The easiest and most efficient method of creating a Decimal is to use the procedural macro within the `rust_decimal_macros` crate: + +```rust +// Procedural macros need importing directly +use rust_decimal_macros::dec; + +let number = dec!(-1.23) + dec!(3.45); +assert_eq!(number, dec!(2.22)); +assert_eq!(number.to_string(), "2.22"); +``` + +Alternatively you can also use one of the Decimal number convenience functions ([see the docs](https://docs.rs/rust_decimal/) for more details): + +```rust +// Using the prelude can help importing trait based functions (e.g. core::str::FromStr). +use rust_decimal::prelude::*; + +// Using an integer followed by the decimal points +let scaled = Decimal::new(202, 2); +assert_eq!("2.02", scaled.to_string()); + +// From a 128 bit integer +let balance = Decimal::from_i128_with_scale(5_897_932_384_626_433_832, 2); +assert_eq!("58979323846264338.32", balance.to_string()); + +// From a string representation +let from_string = Decimal::from_str("2.02").unwrap(); +assert_eq!("2.02", from_string.to_string()); + +// From a string representation in a different base +let from_string_base16 = Decimal::from_str_radix("ffff", 16).unwrap(); +assert_eq!("65535", from_string_base16.to_string()); + +// From scientific notation +let sci = Decimal::from_scientific("9.7e-7").unwrap(); +assert_eq!("0.00000097", sci.to_string()); + +// Using the `Into` trait +let my_int: Decimal = 3_i32.into(); +assert_eq!("3", my_int.to_string()); + +// Using the raw decimal representation +let pi = Decimal::from_parts(1_102_470_952, 185_874_565, 1_703_060_790, false, 28); +assert_eq!("3.1415926535897932384626433832", pi.to_string()); +``` + +Once you have instantiated your `Decimal` number you can perform calculations with it just like any other number: + +```rust +use rust_decimal::prelude::*; +use rust_decimal_macros::dec; + +let amount = dec!(25.12); +let tax_percentage = dec!(0.085); +let total = amount + (amount * tax_percentage).round_dp(2); +assert_eq!(total, dec!(27.26)); +``` + +## Features + +**Behavior / Functionality** + +* [borsh](#borsh) +* [c-repr](#c-repr) +* [legacy-ops](#legacy-ops) +* [maths](#maths) +* [rkyv](#rkyv) +* [rocket-traits](#rocket-traits) +* [rust-fuzz](#rust-fuzz) +* [std](#std) + +**Database** + +* [db-postgres](#db-postgres) +* [db-tokio-postgres](#db-tokio-postgres) +* [db-diesel-postgres](#db-diesel-postgres) +* [db-diesel-mysql](#db-diesel-mysql) + +**Serde** + +* [serde-float](#serde-float) +* [serde-str](#serde-str) +* [serde-arbitrary-precision](#serde-arbitrary-precision) +* [serde-with-float](#serde-with-float) +* [serde-with-str](#serde-with-str) +* [serde-with-arbitrary-precision](#serde-with-arbitrary-precision) + +### `borsh` + +Enables [Borsh](https://borsh.io/) serialization for `Decimal`. + +### `c-repr` + +Forces `Decimal` to use `[repr(C)]`. The corresponding target layout is 128 bit aligned. + +### `db-postgres` + +Enables a PostgreSQL communication module. It allows for reading and writing the `Decimal` +type by transparently serializing/deserializing into the `NUMERIC` data type within PostgreSQL. + +### `db-tokio-postgres` + +Enables the tokio postgres module allowing for async communication with PostgreSQL. + +### `db-diesel-postgres` + +Enable `diesel` PostgreSQL support. By default, this enables version `1.4` of `diesel`. If you wish to use the `2.0` +version of `diesel` then you can do so by using the feature `db-diesel2-postgres`. Please note, if both features are +enabled then version 2 will supersede version 1. + +### `db-diesel-mysql` + +Enable `diesel` MySQL support. By default, this enables version `1.4` of `diesel`. If you wish to use the `2.0` +version of `diesel` then you can do so by using the feature `db-diesel2-mysql`. Please note, if both features are +enabled then version 2 will supersede version 1. + +### `legacy-ops` + +**Warning:** This is deprecated and will be removed from a future versions. + +As of `1.10` the algorithms used to perform basic operations have changed which has benefits of significant speed improvements. +To maintain backwards compatibility this can be opted out of by enabling the `legacy-ops` feature. + +### `maths` + +The `maths` feature enables additional complex mathematical functions such as `pow`, `ln`, `enf`, `exp` etc. +Documentation detailing the additional functions can be found on the +[`MathematicalOps`](https://docs.rs/rust_decimal/latest/rust_decimal/trait.MathematicalOps.html) trait. + +Please note that `ln` and `log10` will panic on invalid input with `checked_ln` and `checked_log10` the preferred functions +to curb against this. When the `maths` feature was first developed the library would return `0` on invalid input. To re-enable this +non-panicking behavior, please use the feature: `maths-nopanic`. + +### `rand` + +Implements `rand::distributions::Distribution<Decimal>` to allow the creation of random instances. + +Note: When using `rand::Rng` trait to generate a decimal between a range of two other decimals, the scale of the randomly-generated +decimal will be the same as the scale of the input decimals (or, if the inputs have different scales, the higher of the two). + +### `rkyv` +Enables [rkyv](https://github.com/rkyv/rkyv) serialization for `Decimal`. +Supports rkyv's safe API when the `rkyv-safe` feature is enabled as well. + +### `rocket-traits` + +Enable support for Rocket forms by implementing the `FromFormField` trait. + +### `rust-fuzz` + +Enable `rust-fuzz` support by implementing the `Arbitrary` trait. + +### `serde-float` + +**Note:** it is recommended to use the `serde-with-*` features for greater control. This allows configurability at the data +level. + +Enable this so that JSON serialization of `Decimal` types are sent as a float instead of a string (default). + +e.g. with this turned on, JSON serialization would output: +```json +{ + "value": 1.234 +} +``` + +### `serde-str` + +**Note:** it is recommended to use the `serde-with-*` features for greater control. This allows configurability at the data +level. + +This is typically useful for `bincode` or `csv` like implementations. + +Since `bincode` does not specify type information, we need to ensure that a type hint is provided in order to +correctly be able to deserialize. Enabling this feature on its own will force deserialization to use `deserialize_str` +instead of `deserialize_any`. + +If, for some reason, you also have `serde-float` enabled then this will use `deserialize_f64` as a type hint. Because +converting to `f64` _loses_ precision, it's highly recommended that you do NOT enable this feature when working with +`bincode`. That being said, this will only use 8 bytes so is slightly more efficient in terms of storage size. + +### `serde-arbitrary-precision` + +**Note:** it is recommended to use the `serde-with-*` features for greater control. This allows configurability at the data +level. + +This is used primarily with `serde_json` and consequently adds it as a "weak dependency". This supports the +`arbitrary_precision` feature inside `serde_json` when parsing decimals. + +This is recommended when parsing "float" looking data as it will prevent data loss. + +### `serde-with-float` + +Enable this to access the module for serializing `Decimal` types to a float. This can be use in `struct` definitions like so: + +```rust +#[derive(Serialize, Deserialize)] +pub struct FloatExample { + #[serde(with = "rust_decimal::serde::float")] + value: Decimal, +} +``` +```rust +#[derive(Serialize, Deserialize)] +pub struct OptionFloatExample { + #[serde(with = "rust_decimal::serde::float_option")] + value: Option<Decimal>, +} +``` + +### `serde-with-str` + +Enable this to access the module for serializing `Decimal` types to a `String`. This can be use in `struct` definitions like so: + +```rust +#[derive(Serialize, Deserialize)] +pub struct StrExample { + #[serde(with = "rust_decimal::serde::str")] + value: Decimal, +} +``` +```rust +#[derive(Serialize, Deserialize)] +pub struct OptionStrExample { + #[serde(with = "rust_decimal::serde::str_option")] + value: Option<Decimal>, +} +``` + +### `serde-with-arbitrary-precision` + +Enable this to access the module for serializing `Decimal` types to a `String`. This can be use in `struct` definitions like so: + +```rust +#[derive(Serialize, Deserialize)] +pub struct ArbitraryExample { + #[serde(with = "rust_decimal::serde::arbitrary_precision")] + value: Decimal, +} +``` +```rust +#[derive(Serialize, Deserialize)] +pub struct OptionArbitraryExample { + #[serde(with = "rust_decimal::serde::arbitrary_precision_option")] + value: Option<Decimal>, +} +``` + +### `std` + +Enable `std` library support. This is enabled by default, however in the future will be opt in. For now, to support `no_std` +libraries, this crate can be compiled with `--no-default-features`. + +## Building + +Please refer to the [Build document](BUILD.md) for more information on building and testing Rust Decimal. + +## Minimum Rust Compiler Version + +The current _minimum_ compiler version is [`1.60.0`](https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1600-2022-04-07) +which was released on `2022-04-07`. + +This library maintains support for rust compiler versions that are 4 minor versions away from the current stable rust compiler version. +For example, if the current stable compiler version is `1.50.0` then we will guarantee support up to and including `1.46.0`. +Of note, we will only update the minimum supported version if and when required. |