Files
darkfi/src/util/parse.rs
2024-03-05 08:47:43 +01:00

105 lines
3.2 KiB
Rust

/* This file is part of DarkFi (https://dark.fi)
*
* Copyright (C) 2020-2024 Dyne.org foundation
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
use std::str::FromStr;
use crate::{Error, Result};
pub fn decode_base10(amount: &str, decimal_places: usize, strict: bool) -> Result<u64> {
let mut s: Vec<char> = amount.to_string().chars().collect();
// Get rid of the decimal point:
let point: usize = if let Some(p) = amount.find('.') {
s.remove(p);
p
} else {
s.len()
};
// Only digits should remain
for i in &s {
if !i.is_ascii_digit() {
return Err(Error::ParseFailed("Found non-digits"))
}
}
// Add digits to the end if there are too few:
let actual_places = s.len() - point;
if actual_places < decimal_places {
s.extend(vec!['0'; decimal_places - actual_places])
}
// Remove digits from the end if there are too many:
let mut round = false;
if actual_places > decimal_places {
let end = point + decimal_places;
for i in &s[end..s.len()] {
if *i != '0' {
round = true;
break
}
}
s.truncate(end);
}
if strict && round {
return Err(Error::ParseFailed("Would end up rounding while strict"))
}
// Convert to an integer
let number = u64::from_str(&String::from_iter(&s))?;
// Round and return
if round && number == u64::MAX {
return Err(Error::ParseFailed("u64 overflow"))
}
Ok(number + round as u64)
}
pub fn encode_base10(amount: u64, decimal_places: usize) -> String {
let mut s: Vec<char> =
format!("{:0width$}", amount, width = 1 + decimal_places).chars().collect();
s.insert(s.len() - decimal_places, '.');
String::from_iter(&s).trim_end_matches('0').trim_end_matches('.').to_string()
}
#[cfg(test)]
mod tests {
use super::{decode_base10, encode_base10};
#[test]
fn test_decode_base10() {
assert_eq!(124, decode_base10("12.33", 1, false).unwrap());
assert_eq!(1233000, decode_base10("12.33", 5, false).unwrap());
assert_eq!(1200000, decode_base10("12.", 5, false).unwrap());
assert_eq!(1200000, decode_base10("12", 5, false).unwrap());
assert!(decode_base10("12.33", 1, true).is_err());
}
#[test]
fn test_encode_base10() {
assert_eq!("23.4321111", &encode_base10(234321111, 7));
assert_eq!("23432111.1", &encode_base10(234321111, 1));
assert_eq!("234321.1", &encode_base10(2343211, 1));
assert_eq!("2343211", &encode_base10(2343211, 0));
assert_eq!("0.00002343", &encode_base10(2343, 8));
}
}