Refactor things into separate files for easier reading

src/formatters/ansi.cr

@@ -0,0 +1,37 @@
+require "../formatter"
+
+module Tartrazine
+  class Ansi < Formatter
+    def format(text : String, lexer : Lexer, theme : Theme) : String
+      output = String.build do |outp|
+        lexer.tokenize(text).each do |token|
+          outp << self.colorize(token[:value], token[:type], theme)
+        end
+      end
+      output
+    end
+
+    def colorize(text : String, token : String, theme : Theme) : String
+      style = theme.styles.fetch(token, nil)
+      return text if style.nil?
+      if theme.styles.has_key?(token)
+        s = theme.styles[token]
+      else
+        # Themes don't contain information for each specific
+        # token type. However, they may contain information
+        # for a parent style. Worst case, we go to the root
+        # (Background) style.
+        s = theme.styles[theme.style_parents(token).reverse.find { |parent|
+          theme.styles.has_key?(parent)
+        }]
+      end
+      colorized = text.colorize
+      s.color.try { |c| colorized = colorized.fore(c.colorize) }
+      # Intentionally not setting background color
+      colorized.mode(:bold) if s.bold
+      colorized.mode(:italic) if s.italic
+      colorized.mode(:underline) if s.underline
+      colorized.to_s
+    end
+  end
+end