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chain: touch up amount docs

This commit is contained in:
Henry de Valence 2020-08-15 22:18:30 -07:00
parent d0ee7a9961
commit 9766d32fa6
1 changed files with 26 additions and 5 deletions
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31
zebra-chain/src/amount.rs
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@ -1,4 +1,9 @@
//! Strongly-typed zatoshi amounts that prevent under/overflows.
//!
//! The [`Amount`] type is parameterized by a [`Constraint`] implementation that
//! declares the range of allowed values. In contrast to regular arithmetic
//! operations, which return values, arithmetic on [`Amount`]s returns
//! [`Result`]s.
use std::{
convert::{TryFrom, TryInto},
@ -201,9 +206,17 @@ pub enum Error {
},
}
/// Marker type for `Amount` that allows negative values.
///
/// ```
/// # use zebra_chain::amount::{Constraint, MAX_MONEY, NegativeAllowed};
/// assert_eq!(
/// NegativeAllowed::valid_range(),
/// -MAX_MONEY..=MAX_MONEY,
/// );
/// ```
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
/// Marker type for `Amount` that restricts the values to `-MAX_MONEY..=MAX_MONEY`
pub enum NegativeAllowed {}
pub struct NegativeAllowed {}
impl Constraint for NegativeAllowed {
fn valid_range() -> RangeInclusive<i64> {
@ -211,9 +224,17 @@ impl Constraint for NegativeAllowed {
}
}
/// Marker type for `Amount` that requires nonnegative values.
///
/// ```
/// # use zebra_chain::amount::{Constraint, MAX_MONEY, NonNegative};
/// assert_eq!(
/// NonNegative::valid_range(),
/// 0..=MAX_MONEY,
/// );
/// ```
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
/// Marker type for `Amount` that restricts the value to positive numbers `0..=MAX_MONEY`
pub enum NonNegative {}
pub struct NonNegative {}
impl Constraint for NonNegative {
fn valid_range() -> RangeInclusive<i64> {
@ -221,7 +242,7 @@ impl Constraint for NonNegative {
}
}
/// The max amount of money that can be obtained in zatoshis
/// The maximum zatoshi amount.
pub const MAX_MONEY: i64 = 21_000_000 * 100_000_000;
/// A trait for defining constraints on `Amount`