Use colored in symbol table debug

Cargo.lock

@@ -728,6 +728,7 @@ dependencies = [
 name = "schala-lang"
 version = "0.1.0"
 dependencies = [
+ "colored 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "derivative 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",

schala-lang/language/Cargo.toml

@@ -13,6 +13,7 @@ failure = "0.1.5"
 ena = "0.11.0"
 stopwatch = "0.0.7"
 derivative = "1.0.3"
+colored = "1.8"
 
 schala-lang-codegen = { path = "../codegen" }
 schala-repl = { path = "../../schala-repl" }

schala-lang/language/src/lib.rs

@@ -17,6 +17,7 @@ extern crate schala_repl;
 extern crate schala_lang_codegen;
 extern crate ena;
 extern crate derivative;
+extern crate colored;
 
 
 macro_rules! bx {

schala-lang/language/src/symbol_table.rs

@@ -32,13 +32,14 @@ pub struct ScopeSegment {
 
 impl fmt::Display for ScopeSegment {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    use colored::*;
     use ScopeSegmentKind::*;
     let kind = match self.kind {
-      Function => "fn",
-      Type => "ty",
-      Terminal => "tr",
+      Function => "[fn]".green(),
+      Type => "[ty]".red(),
+      Terminal => "[tr]".blue(),
     };
-    write!(f, "{}({})", self.name, kind)
+    write!(f, "{}{}", self.name, kind)
   }
 }