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use nom::bytes::complete::{tag, take_while_m_n};
use nom::combinator::map_res;
use nom::sequence::tuple;
use nom::IResult;
#[derive(Debug, PartialEq)]
pub struct Color {
pub red: u8,
pub green: u8,
pub blue: u8,
}
fn from_hex(input: &str) -> Result<u8, std::num::ParseIntError> {
u8::from_str_radix(input, 16)
}
fn is_hex_digit(c: char) -> bool {
c.is_digit(16)
}
fn hex_primary(input: &str) -> IResult<&str, u8> {
map_res(take_while_m_n(2, 2, is_hex_digit), from_hex)(input)
}
fn hex_color(input: &str) -> IResult<&str, Color> {
let (input, _) = tag("#")(input)?;
let (input, (red, green, blue)) = tuple((hex_primary, hex_primary, hex_primary))(input)?;
Ok((input, Color { red, green, blue }))
}
#[test]
fn parse_color() {
assert_eq!(
hex_color("#2F14DF"),
Ok((
"",
Color {
red: 47,
green: 20,
blue: 223,
}
))
);
}