Lotus/lib.rs
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//! # Lotus
//! `Lotus` is a simple library to provide formatting for currency and numbers.
//! It makes pretty printing of monetary values convenient.
//!
//! # Usage
//! ```
//! # #[macro_use]
//! # use crate::Lotus::*;
//! // Builder format (recommended)
//! let rupee = LotusBuilder::default()
//! .symbol("Rs.")
//! .precision(1)
//! .format_positive("{symbol} {value}")
//! .format_negative("{symbol} ({value})")
//! .format_zero("{symbol} 0.00")
//! .decimal_str(".")
//! .thousand_str(" ")
//! .build()
//! .unwrap();
//! assert_eq!("Rs. 2 000 000.0", rupee.format(2_000_000));
//! assert_eq!("Rs. (2 000.0)", rupee.format(-2000));
//! assert_eq!("Rs. 0.00", rupee.format(0));
//!
//! // Using Lotus::new()
//! let dollar = Lotus::new("$", 3); // Lotus::new(symbol, precision)
//! assert_eq!("$ 50,000.035", dollar.format(50_000.035));
//!
//! // Using lotus! macro
//! let f = lotus!(150, "$"); // lotus!(number, symbol)
//! assert_eq!("$ 150.00", f);
//!
//! let g = lotus!(2_000_000); // lotus!(number)
//! assert_eq!("2,000,000.00", g);
//! ```
use std::default::Default;
#[macro_use]
extern crate derive_builder;
#[macro_use]
mod macros;
mod tests;
#[derive(Debug, Builder)]
#[builder(default)]
pub struct Lotus<'a> {
symbol: &'a str,
precision: u8,
thousand_str: &'a str,
decimal_str: &'a str,
format_positive: &'a str,
format_negative: &'a str,
format_zero: &'a str
}
impl<'a> Lotus<'a> {
/// Creates a Lotus instance with the give symbol and precision
/// and precision
///
/// # Example:
/// ```
/// use crate::Lotus::*;
/// let dollar = Lotus::new("$", 2);
/// let f = dollar.format(3500);
/// assert_eq!("$ 3,500.00", f);
/// ```
pub fn new(symbol: &str, precision: u8) -> Lotus {
Lotus {
symbol,
precision,
..Default::default()
}
}
/// Formats a (generic) number according to the object
/// configuration
///
/// # Example:
/// ```
/// use crate::Lotus::*;
/// let rupee = LotusBuilder::default()
/// .symbol("Rs.")
/// .precision(4)
/// .format_positive("{symbol} {value}")
/// .format_negative("{symbol} ({value})")
/// .format_zero("{symbol} 0.00")
/// .decimal_str(".")
/// .thousand_str(" ")
/// .build()
/// .unwrap();
/// assert_eq!("Rs. 2 000 000.0000", rupee.format(2_000_000));
/// ```
pub fn format<T: Into<f64>>(&self, in_number: T) -> String {
let number: f64 = in_number.into();
if number == 0. {
let value = format!("{:.*}", self.precision as usize, number);
let currencied = self.format_zero.replace("{value}", value.as_str());
return currencied.replace("{symbol}", self.symbol)
} else {
let value = format!("{:.*}", self.precision as usize, number.abs());
let mut float_iter = value.split(".");
let integral = float_iter.next().unwrap();
let fractional = float_iter.next().unwrap();
let mut formatted_integral = String::new();
for ( i, letter ) in integral.chars().rev().enumerate() {
if i % 3 == 0 && i != 0 && letter != '-' {
formatted_integral.push_str(&self.thousand_str[..]);
}
formatted_integral.push(letter);
}
let formatted_integral = formatted_integral.chars().rev().collect::<String>();
let formatted_float = format!("{}{}{}", formatted_integral, self.decimal_str, fractional);
let mut currencied = String::new();
if number.is_sign_negative() {
currencied.push_str(self.format_negative);
} else {
currencied.push_str(self.format_positive);
}
currencied = currencied.replace("{value}", formatted_float.as_str());
currencied = currencied.replace("{symbol}", &self.symbol[..]);
return currencied;
}
}
}
impl<'a> Default for Lotus<'a> {
fn default() -> Self {
Lotus {
symbol: "$",
precision: 2,
thousand_str: ",",
decimal_str: ".",
format_positive: "{symbol} {value}",
format_negative: "{symbol} ({value})",
format_zero: "{symbol} --",
}
}
}