Added some colours to the terminal output.

Cargo.lock

@@ -1,5 +1,14 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "ansi_term"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "arrayref"
 version = "0.3.6"
@@ -113,6 +122,7 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 name = "lek"
 version = "0.1.0"
 dependencies = [
+ "ansi_term",
  "phf",
  "rustyline",
 ]

Cargo.toml

@@ -13,3 +13,4 @@ panic = "abort"
 [dependencies]
 rustyline = "6.1.2"
 phf = { version = "0.8", features = ["macros"] }
+ansi_term = "0.12"

src/main.rs

@@ -7,9 +7,10 @@ mod parser;
 mod prelude;
 mod symbol_table;
 
+use ansi_term::Colour::{Cyan, Red};
+use ast::Unit;
 use rustyline::error::ReadlineError;
 use rustyline::Editor;
-use ast::Unit;
 
 fn main() {
     let mut parser = parser::Context::new();
@@ -24,7 +25,7 @@ fn main() {
     let mut rl = Editor::<()>::new();
 
     loop {
-        let readline = rl.readline(">> ");
+        let readline = rl.readline(&Cyan.paint(">> ").to_string());
 
         match readline {
             Ok(input) => {
@@ -50,7 +51,7 @@ fn eval(parser: &mut parser::Context, input: &str) {
     match parser::parse(parser, input, get_angle_unit()) {
         Ok(Some(result)) => println!("{}", result),
         Ok(None) => print!(""),
-        Err(err) => println!("{}", err),
+        Err(err) => println!("{}", Red.paint(err)),
     }
 }