diff --git a/src/lexer.cr b/src/lexer.cr
index 04bf093..a515baf 100644
--- a/src/lexer.cr
+++ b/src/lexer.cr
@@ -10,37 +10,44 @@ module Tartrazine
   # Get the lexer object for a language name
   # FIXME: support mimetypes
   def self.lexer(name : String? = nil, filename : String? = nil) : BaseLexer
-    if name.nil? && filename.nil?
-      lexer_file_name = LEXERS_BY_NAME["plaintext"]
-    elsif name && name != "autodetect"
-      lexer_file_name = LEXERS_BY_NAME.fetch(name.downcase, nil)
-      if lexer_file_name.nil? && name.includes? "+"
-        # Delegating lexer
-        language, root = name.split("+", 2)
-        language_lexer = lexer(language)
-        root_lexer = lexer(root)
-        return DelegatingLexer.new(language_lexer, root_lexer)
-      elsif lexer_file_name.nil?
-        raise Exception.new("Unknown lexer: #{name}")
-      end
-    else
-      # Guess by filename
-      candidates = Set(String).new
-      LEXERS_BY_FILENAME.each do |k, v|
-        candidates += v.to_set if File.match?(k, File.basename(filename.to_s))
-      end
-      case candidates.size
-      when 0
-        lexer_file_name = LEXERS_BY_NAME["plaintext"]
-      when 1
-        lexer_file_name = candidates.first
-      else
-        raise Exception.new("Multiple lexers match the filename: #{candidates.to_a.join(", ")}")
-      end
-    end
+    return lexer_by_name(name) if name && name != "autodetect"
+    return lexer_by_filename(filename) if filename
+  
+    Lexer.from_xml(LexerFiles.get("/#{LEXERS_BY_NAME["plaintext"]}.xml").gets_to_end)
+  end
+  
+  private def self.lexer_by_name(name : String) : BaseLexer
+    lexer_file_name = LEXERS_BY_NAME.fetch(name.downcase, nil)
+    return create_delegating_lexer(name) if lexer_file_name.nil? && name.includes? "+"
+    raise Exception.new("Unknown lexer: #{name}") if lexer_file_name.nil?
+  
     Lexer.from_xml(LexerFiles.get("/#{lexer_file_name}.xml").gets_to_end)
   end
-
+  
+  private def self.lexer_by_filename(filename : String) : BaseLexer
+    candidates = Set(String).new
+    LEXERS_BY_FILENAME.each do |k, v|
+      candidates += v.to_set if File.match?(k, File.basename(filename))
+    end
+  
+    case candidates.size
+    when 0
+      lexer_file_name = LEXERS_BY_NAME["plaintext"]
+    when 1
+      lexer_file_name = candidates.first
+    else
+      raise Exception.new("Multiple lexers match the filename: #{candidates.to_a.join(", ")}")
+    end
+  
+    Lexer.from_xml(LexerFiles.get("/#{lexer_file_name}.xml").gets_to_end)
+  end
+  
+  private def self.create_delegating_lexer(name : String) : BaseLexer
+    language, root = name.split("+", 2)
+    language_lexer = lexer(language)
+    root_lexer = lexer(root)
+    DelegatingLexer.new(language_lexer, root_lexer)
+  end
   # Return a list of all lexers
   def self.lexers : Array(String)
     LEXERS_BY_NAME.keys.sort!