Basic functionality

.gitignore

+/target
+.idea
\ No newline at end of file

Cargo.lock

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Cargo.toml

+[package]
+name = "lolcatrs"
+version = "0.1.0"
+authors = ["Stephen <webmaster@scd31.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+colored = "2.0"
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\ No newline at end of file

README.md

+# Lolcat.rs
+
+Why?
+
+```
+$ time echo hi | lolcat
+real    0m0.422s
+user    0m0.393s
+sys	    0m0.028s
+```
+
+I use lolcat in my `.bashrc` file, so this amount of time is not ideal for me.
+

src/lol.rs

+use colored::{ColoredString, Colorize};
+use std::f64::consts;
+use std::io::{stdout, Write};
+use std::process::exit;
+
+fn rainbow(freq: f64, i: f64) -> (u8, u8, u8) {
+    let red = ((freq * i).sin() * 127.0) as u8 + 128;
+    let green = ((freq * i + 2.0 * consts::PI / 3.0).sin() * 127.0) as i16 + 128;
+    let blue = ((freq * i + 4.0 * consts::PI / 3.0).sin() * 127.0) as i16 + 128;
+    (red as u8, green as u8, blue as u8)
+}
+
+pub fn print_rainbow(line: &str, freq: f64, seed: f64, spread: f64, invert: bool) {
+    let t = line
+        .chars()
+        .enumerate()
+        .map(|(i, c)| {
+            let (r, g, b) = rainbow(freq, seed + i as f64 / spread);
+            if invert {
+                if c == '\n' || c == '\r' {
+                    c.to_string().normal()
+                } else {
+                    c.to_string().on_truecolor(r, g, b)
+                }
+            } else {
+                c.to_string().truecolor(r, g, b)
+            }
+        })
+        .fold("".to_string(), |acc, v| format!("{}{}", acc, v));
+    if stdout().write_all(t.as_bytes()).is_err() {
+        exit(0);
+    }
+}

src/main.rs

+use std::io;
+use std::process::exit;
+mod lol;
+
+fn read_line() -> Option<(String, usize)> {
+    let mut input = String::new();
+    match io::stdin().read_line(&mut input) {
+        Ok(n) => Some((input, n)),
+        _ => None,
+    }
+}
+
+fn main() {
+    let mut seed: f64 = rand::random::<f64>() * 1_000_000.0;
+    while let Some((x, n)) = read_line() {
+        lol::print_rainbow(&x, 0.1, seed, 3.0, true);
+        if n == 0 {
+            // EOF
+            exit(0);
+        }
+        seed += 1.0;
+    }
+}