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#![crate_name = "rspark"]
pub mod rspark {
use std::error::Error;
use std::fmt;
const TICKS: [char; 8] = [
'\u{2581}', '\u{2582}', '\u{2583}', '\u{2584}', '\u{2585}', '\u{2586}', '\u{2587}',
'\u{2588}',
];
pub fn render(v: &Vec<i32>) -> Result<String, RenderError> {
let mut s = String::new();
render_to(v, &mut s)
.map(|ok_val| ok_val.to_string())
.map_err(|err_val| err_val)
}
pub fn render_to<'a>(v: &Vec<i32>, s: &'a mut String) -> Result<&'a str, RenderError> {
if v.len() < 2 {
return Err(RenderError::InvalidVectorParameter);
}
let max = v.iter().max().unwrap();
let min = v.iter().min().unwrap();
let scale = (max - min) as f32 / 7.;
for e in v.iter() {
let i = (e - min) / scale as i32;
(*s).push_str(&TICKS[i as usize].to_string());
}
Ok(&s[..])
}
#[derive(Debug)]
pub enum RenderError {
InvalidVectorParameter,
}
impl fmt::Display for RenderError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
RenderError::InvalidVectorParameter => f.write_str("InvalidVectorParameter"),
}
}
}
impl Error for RenderError {
fn description(&self) -> &str {
match *self {
RenderError::InvalidVectorParameter => "Invalid vector parameter",
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_render() {
let v = vec![2, 250, 670, 890, 2, 430, 11, 908, 123, 57];
let res = rspark::render(&v).unwrap();
println!("{}", res);
assert_eq!("▁▂▆▇▁▄▁█▁▁", res);
}
#[test]
fn test_render_to() {
let v = vec![2, 250, 670, 890, 2, 430, 11, 908, 123, 57];
let mut s = String::new();
let res = rspark::render_to(&v, &mut s).unwrap();
println!("{}", res);
assert_eq!("▁▂▆▇▁▄▁█▁▁", res);
}
#[test]
fn test_render_err() {
let v = vec![2];
let res = rspark::render(&v);
match res {
Ok(_) => panic!("Error expected."),
_ => (),
}
}
}