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//! The crate contains macros for generating fixed-size fixed-point numeric types
//! that exactly fit your domain. The types are fully equipped for performing mathematical
//! computations and are easy to use.
//!
//! With a simple macro call you get a numeric type that:
//!
//! - has no representation errors in the range, defined by the type parameters,
//! - supports arithmetic operations: `+`, `-`, `*`, `/`, `%`, `<<`, `>>`,
//! - comes with mathematical functions: `abs()`, `powi()`, `sqrt()`,
//! - has special values NaN and ±Infinity, and uses them instead of panicing,
//! - provides basic mathematical constants,
//! - seamlessly interacts with Rust's primitive types,
//! - converts values to/from byte arrays,
//! - creates values and performs math operations on stack, avoiding heap allocations.
//!
//! ## When to Use
//!
//! You should probably give fdec a try if:
//!
//! - you need primitive types like `i256` or `i1408`, which Rust doesn't provide,
//! - your business domain is not tolerant to representation errors that may add up during computations (like working with money in finance),
//! - other libraries that provide decimal numbers are not fast enough for you when it comes to doing math,
//! - you need to store lots of decimal numbers, and you'd prefer it to be memory-efficient,
//! - you're just curious to see how it works.
//!
//! # How to Use
//!
//! Add the dependency on `fdec` to your `Cargo.toml`:
//!
//! ```toml
//! [dependencies]
//! fdec = "0.3.1"
//! ```
//!
//! Import it at your crate's root with the `macro_use` attribute:
//!
//! ```
//! #[macro_use]
//! extern crate fdec;
//! # fn main() {}
//! ```
//!
//! Add custom numeric types to your project by calling `fdec*` macros:
//!
//! ```
//! # #[macro_use] extern crate fdec;
//! fdec64! { // Use 64-bit units
//! module bigdec, // Put all the generated code into the `bigdec` module
//! name BigDec, // The name for the generated type
//! length 5, // 5 * 64-bit units = 320 bits to store numbers
//! scale 50 // Use 50 decimal places
//! }
//! ```
//!
//! # Example
//!
//! Here we define the `Decimal` structure that represents 160-bit numbers
//! with 30 decimal places.
//!
//! ```
//! #[macro_use]
//! extern crate fdec;
//!
//! fdec32! { // Use 32-bit units
//! module dec, // Put all the generated code into the `dec` module
//! name Decimal, // Name the main struct `Decimal`
//! length 5, // 5 * 32-bit units = 160 bits to store numbers
//! scale 30 // Use 30 decimal places
//! }
//!
//! use dec::*; // Bring the generated stuff to the scope
//!
//! fn main() {
//! // Use it
//! let a = Decimal::one();
//! let b = Decimal::from(14);
//! let c = dec!(9);
//! let result = a + 30 * (b / c).powi(3);
//! println!("{} + 30 * ({} / {})^3 = {}", a, b, c, result);
//! // 1 + 30 * (14 / 9)^3 = 113.92181069958847736625514403278
//! }
//! ```
//!
//! [More examples](https://github.com/alygin/fdec/tree/master/examples) come with the crate's
//! source code.
//!
//! See the [`Number`] trait to find out what the generated types are capable of.
extern crate lazy_static;
use std::fmt::{Debug, Display};
use std::ops::{Add, Div, Mul, Neg, Rem, Shr, Sub};
use std::str::FromStr;
#[doc(hidden)]
pub use lazy_static::*;
#[cfg(test)]
mod binomial;
#[doc(hidden)]
pub mod consts;
mod number;
mod prim;
/// Trait of types that can create values from other types with scaling.
pub trait WithScale<T> {
/// Creates a number from the given value, applying the given scale to it.
fn with_scale(v: T, scale: usize) -> Self;
}
/// Trait that is implemented by all numeric types, generated by `fdec`.
pub trait Number:
Default
+ Display
+ Debug
+ PartialEq
+ PartialOrd
+ Neg<Output = Self>
+ Add<Output = Self>
+ Sub<Output = Self>
+ Mul<Output = Self>
+ Div<Output = Self>
+ Rem<Output = Self>
+ FromStr
+ From<u8>
+ From<u16>
+ From<u32>
+ From<u64>
+ WithScale<u8>
+ WithScale<u16>
+ WithScale<u32>
+ WithScale<u64>
+ Shr<usize>
{
/// Number of decimal places in numbers.
const SCALE: usize;
/// Number of units that are used to store numbers.
const LENGTH: usize;
/// Returns the zero value.
fn zero() -> Self;
/// Returns the `1` value.
fn one() -> Self;
/// Returns the smallest positive value.
fn ulp() -> Self;
/// Returns the largest normal value.
fn max() -> Self;
/// Returns the smallest normal value.
fn min() -> Self;
/// Returns the value that represents positive infinity.
fn infinity() -> Self;
/// Returns the value that represents negative infinity.
fn neg_infinity() -> Self;
/// Returns the value that represents NaN (Not a Number).
fn nan() -> Self;
/// Returns `true` if the number is negative (including -Infinity) and `false` if the number is zero or positive.
fn is_sign_negative(&self) -> bool;
/// Returns `true` if the number is zero or positive (including +Infinity) and `false` if the number is negative.
fn is_sign_positive(&self) -> bool;
/// Returns `true` if this value is positive infinity or negative infinity and `false` otherwise.
fn is_infinite(&self) -> bool;
/// Returns `true` if this value is NaN (Not a Number) and `false` otherwise.
fn is_nan(&self) -> bool;
/// Returns `true` if this values is NaN or ±Infinity.
fn is_special(&self) -> bool;
/// Returns `true` if the number is zero.
fn is_zero(&self) -> bool;
/// Returns the absolute value of the number.
fn abs(&self) -> Self;
/// Returns the integral part of the number.
fn trunc(&self) -> Self;
/// Returns the fraction part of the number.
fn fract(&self) -> Self;
/// Returns the square root of the number.
fn sqrt(&self) -> Self;
/// Returns the number raised to the given integer power.
fn powi(&self, n: i32) -> Self;
}
/// Represents errors that can be produced when strings are parsed to numbers.
#[derive(PartialEq, Eq, Debug)]
pub enum ParseNumberError {
/// String has invalid format and cannot be parsed.
InvalidFormat,
/// String represents a value that doesn't fit into the numeric type.
Overflow,
}
/// Represents errors that can be produces when byte arrays are converted to numbers.
#[derive(PartialEq, Eq, Debug)]
pub enum FromBytesError {
/// Flags-byte has invalid value.
InvalidFlags,
}
/// Generates a fixed-size fixed-point numeric type that uses `u8`'s as building blocks.
///
/// # Examples
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec8! { // Use 8-bit units as building blocks
/// module decimal, // Name of the module that will contain all the generated code
/// name Dec, // Name of the numeric type to be generated
/// length 7, // 56-bit number (7 * 8-bit units)
/// scale 8 // 8 decimal places
/// }
///
/// # fn main() {
/// use std::str::FromStr;
/// use decimal::*;
///
/// let a = Dec::from(13);
/// let b = Dec::from_str("2.47").unwrap();
/// assert_eq!(a + b, Dec::with_scale(1547, 2));
/// # }
/// ```
///
/// The `scale` parameter can be omitted. In this case, the generated type represents integer
/// numbers:
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec8! { // Use 8-bit units as building blocks
/// module int, // Name of the module that will contain all the generated code
/// name Int, // Name of the numeric type to be generated
/// length 10 // 80-bit number (10 * 8-bit units)
/// }
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! fdec8 {
(module $modname:ident, name $name:ident, length $mlen:expr) => {
fdec8!(module $modname, name $name, length $mlen, scale 0);
};
(module $modname:ident, name $name:ident, length $mlen:expr, scale $scale:expr) => {
/// Module that contains the generated numeric type
#[allow(non_upper_case_globals)]
#[macro_use]
pub mod $modname {
fdec!(
u8, u16, i16, 8, 100_u8, 2, 0xff,
module $modname, name $name, length $mlen, scale $scale
);
impl_big_primitive_interop!($name, u16, i16, i16);
impl_big_primitive_interop!($name, u32, i32, i32);
impl_big_primitive_interop!($name, u64, i64, i64);
}
};
}
/// Generates a fixed-size fixed-point numeric type that uses `u16`'s as building blocks.
///
/// # Examples
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec16! { // Use 16-bit units as building blocks
/// module decimal, // Name of the module that will contain all the generated code
/// name Dec, // Name of the numeric type to be generated
/// length 6, // 96-bit number (6 * 16-bit units)
/// scale 12 // 12 decimal places
/// }
///
/// # fn main() {
/// use std::str::FromStr;
/// use decimal::*;
///
/// let a = Dec::from(13);
/// let b = Dec::from_str("2.47").unwrap();
/// assert_eq!(a + b, Dec::with_scale(1547, 2));
/// # }
/// ```
///
/// The `scale` parameter can be omitted. In this case, the generated type represents integer
/// numbers:
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec16! { // Use 16-bit units as building blocks
/// module int, // Name of the module that will contain all the generated code
/// name Int, // Name of the numeric type to be generated
/// length 5 // 80-bit number (5 * 16-bit units)
/// }
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! fdec16 {
(module $modname:ident, name $name:ident, length $mlen:expr) => {
fdec16!(module $modname, name $name, length $mlen, scale 0);
};
(module $modname:ident, name $name:ident, length $mlen:expr, scale $scale:expr) => {
/// Module that contains the generated numeric type
#[allow(non_upper_case_globals)]
#[macro_use]
pub mod $modname {
fdec!(
u16, u32, i32, 16, 10_000_u16, 4, 0xffff,
module $modname, name $name, length $mlen, scale $scale
);
impl_unit_primitive_interop!($name, u16, i16, i16);
impl_big_primitive_interop!($name, u32, i32, i32);
impl_big_primitive_interop!($name, u64, i64, i64);
}
};
}
/// Generates a fixed-size fixed-point numeric type that uses `u32`'s as building blocks.
///
/// # Examples
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec32! { // Use 32-bit units as building blocks
/// module decimal, // Name of the module that will contain all the generated code
/// name Dec, // Name of the numeric type to be generated
/// length 4, // 128-bit number (4 * 32-bit units)
/// scale 8 // 8 decimal places
/// }
///
/// # fn main() {
/// use std::str::FromStr;
/// use decimal::*;
///
/// let a = Dec::from(13);
/// let b = Dec::from_str("2.47").unwrap();
/// assert_eq!(a + b, Dec::with_scale(1547, 2));
/// # }
/// ```
///
/// The `scale` parameter can be omitted. In this case, the generated type represents integer
/// numbers:
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec32! { // Use 32-bit units as building blocks
/// module int, // Name of the module that will contain all the generated code
/// name Int, // Name of the numeric type to be generated
/// length 4 // 128-bit number (4 * 32-bit units)
/// }
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! fdec32 {
(module $modname:ident, name $name:ident, length $mlen:expr) => {
fdec32!(module $modname, name $name, length $mlen, scale 0);
};
(module $modname:ident, name $name:ident, length $mlen:expr, scale $scale:expr) => {
/// Module that contains the generated numeric type
#[allow(non_upper_case_globals)]
#[macro_use]
pub mod $modname {
fdec!(
u32, u64, i64, 32, 1_000_000_000_u32, 9, 0xffffffff,
module $modname, name $name, length $mlen, scale $scale
);
impl_unit_primitive_interop!($name, u16, i16, i16);
impl_unit_primitive_interop!($name, u32, i32, i32);
impl_big_primitive_interop!($name, u64, i64, i64);
}
};
}
/// Generates a fixed-size fixed-point numeric type that uses `u64`'s as building blocks.
///
/// # Examples
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec64! { // Use 64-bit units as building blocks
/// module decimal, // Name of the module that will contain all the generated code
/// name Dec, // Name of the numeric type to be generated
/// length 15, // 960-bit number (15 * 64-bit units)
/// scale 100 // 100 decimal places
/// }
///
/// # fn main() {
/// use std::str::FromStr;
/// use decimal::*;
///
/// let a = Dec::from(13);
/// let b = Dec::from_str("2.47").unwrap();
/// assert_eq!(a + b, Dec::with_scale(1547, 2));
/// # }
/// ```
///
/// The `scale` parameter can be omitted. In this case, the generated type represents integer
/// numbers:
///
/// ```
/// # #[macro_use] extern crate fdec;
/// fdec64! { // Use 64-bit units as building blocks
/// module int, // Name of the module that will contain all the generated code
/// name Int, // Name of the numeric type to be generated
/// length 5 // 320-bit number (5 * 64-bit units)
/// }
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! fdec64 {
(module $modname:ident, name $name:ident, length $mlen:expr) => {
fdec64!(module $modname, name $name, length $mlen, scale 0);
};
(module $modname:ident, name $name:ident, length $mlen:expr, scale $scale:expr) => {
/// Module that contains the generated numeric type
#[allow(non_upper_case_globals)]
#[macro_use]
pub mod $modname {
fdec!(
u64, u128, i128, 64, 10_000_000_000_000_000_000_u64, 19, 0xffffffffffffffff,
module $modname, name $name, length $mlen, scale $scale
);
impl_unit_primitive_interop!($name, u16, i16, i16);
impl_unit_primitive_interop!($name, u32, i32, i32);
impl_unit_primitive_interop!($name, u64, i64, i64);
}
};
}
/// Basic information about the string to be parsed
#[doc(hidden)]
pub struct StrInfo<'a> {
str: &'a str, // String witout leading or trailing zeros
neg: bool, // Indicates that the number is negative
point: Option<usize>, // Position of the decimal point
}
impl<'a> StrInfo<'a> {
#[inline(always)]
pub fn new(str: &'a str, neg: bool, point: Option<usize>) -> StrInfo<'a> {
StrInfo { str, neg, point }
}
#[inline(always)]
pub fn str(&'a self) -> &'a str {
self.str
}
#[inline(always)]
pub fn neg(&self) -> bool {
self.neg
}
#[inline(always)]
pub fn point(&self) -> Option<usize> {
self.point
}
}