Beginning of beautifuler rustc --explain

src/librustc_driver/lib.rs

@@ -263,6 +263,135 @@ pub trait CompilerCalls<'a> {
     fn build_controller(&mut self, &Session) -> CompileController<'a>;
 }
 
+enum Color {
+    Black = 30,
+    Red = 31,
+    Green = 32,
+    Yellow = 33,
+    Blue = 34,
+    Magenta = 35,
+    Cyan = 36,
+    Grey = 37,
+    White = 49
+}
+
+enum Style {
+    NoStyle = 0,
+    Bold = 1
+}
+
+fn get_color(color: Color, style: Style, text: &str) -> String {
+    format!("\x1b[{};1m{}\x1b[0m", color as i32, /*style as i32, */text)
+}
+
+fn parse_input(input: &str) -> String {
+    let lines : Vec<&str> = input.split('\n').collect();
+    let mut out = String::new();
+
+    for line in lines {
+        let words : Vec<&str> = line.split(' ').collect();
+        let mut it = 0;
+
+        while it < words.len() {
+            let word : &str = words[it];
+
+            if word.starts_with("#") {
+                out.push_str(&get_color(Color::White, Style::NoStyle, word));
+                it += 1;
+                continue;
+            }
+            match word {
+                "pub" | "const" | "static" | "crate" | "extern" => {
+                    out.push_str(&get_color(Color::Red, Style::NoStyle, word));
+                }
+                "fn" | "struct" | "mod" | "type" | "enum" | "let" | "match" | "trait" => {
+                    out.push_str(&get_color(Color::Red, Style::NoStyle, word));
+                    out.push_str(&get_color(Color::Red, Style::NoStyle, " "));
+                    it += 1;
+                    if it < words.len() {
+                        out.push_str(&get_color(Color::Blue, Style::NoStyle, words[it]));
+                    }
+                }
+                _ => {
+                    if word.find(' ').is_some() {
+                        let funcs : Vec<&str> = word.split('.').collect();
+
+                        match funcs[funcs.len() - 1].find('(') {
+                            Some(_) => {
+                                let mut i = 0;
+
+                                if funcs.len() > 1 {
+                                    while i < funcs.len() - 2 {
+                                        out.push_str(&get_color(Color::Blue, Style::NoStyle, funcs[i]));
+                                        out.push('.');
+                                        i += 1;
+                                    }
+                                    if i < funcs.len() {
+                                        let func_name : Vec<&str> = funcs[i].split('(').collect();
+                                        out.push_str(&get_color(Color::Blue, Style::NoStyle, func_name[0]));
+                                        i = 1;
+
+                                        while i < func_name.len() {
+                                            out.push('(');
+                                            out.push_str(func_name[i]);
+                                            i += 1;
+                                        }
+                                    }
+                                } else {
+                                    out.push_str(funcs[0]);
+                                }
+                            }
+                            None => {
+                                out.push_str(word);
+                            }
+                        }
+                    } else {
+                        let func_name : Vec<&str> = word.split('(').collect();
+
+
+                        if func_name.len() > 1 {
+                            out.push_str(&get_color(Color::Blue, Style::NoStyle, func_name[0]));
+                            let mut i = 1;
+
+                            while i < func_name.len() {
+                                out.push('(');
+                                out.push_str(func_name[i]);
+                                i += 1;
+                            }
+                        } else {
+                            out.push_str(word);
+                        }
+                    }
+                }
+            }
+            it += 1;
+            if it < words.len() {
+                out.push(' ');
+            }
+        }
+        out.push('\n');
+    }
+    out
+}
+
+fn beautiful_error_printing(splits: &[&str]) -> String {
+    let mut i = 1;
+    let mut s = String::new();
+
+    while i < splits.len() {
+        s.push_str(splits[i - 1]);
+        //s.push_str(&format!("\x1b[{}m", GREEN));
+        s.push_str(&parse_input(splits[i]));
+        //s.push_str(splits[i]);
+        //s.push_str(&format!("\x1b[{}m", NORMAL));
+        i += 2;
+    }
+    if i - 1 < splits.len() {
+        s.push_str(splits[i - 1])
+    }
+    s
+}
+
 // CompilerCalls instance for a regular rustc build.
 #[derive(Copy, Clone)]
 pub struct RustcDefaultCalls;
@@ -277,7 +406,13 @@ impl<'a> CompilerCalls<'a> for RustcDefaultCalls {
                 match descriptions.find_description(&code[..]) {
                     Some(ref description) => {
                         // Slice off the leading newline and print.
-                        print!("{}", &description[1..]);
+                        let tmp_print : Vec<&str> = (&description[1..]).split("```\n").collect();
+
+                        if tmp_print.len() < 2 {
+                            print!("{}", tmp_print[0]);
+                        } else {
+                            print!("{}", beautiful_error_printing(&tmp_print));
+                        }
                     }
                     None => {
                         early_error(&format!("no extended information for {}", code));