Add pattern statement

lib/propane/grammar.rb

@@ -32,6 +32,7 @@ class Propane
       elsif parse_comment_line!
       elsif parse_module_statement!
       elsif parse_class_statement!
+      elsif parse_pattern_statement!
       elsif parse_token_statement!
       elsif parse_tokenid_statement!
       elsif parse_drop_statement!
@@ -125,6 +126,18 @@ class Propane
       end
     end
 
+    def parse_pattern_statement!
+      if pattern = parse_pattern!
+        consume!(/\s+/)
+        unless code = parse_code_block!
+          raise Error.new("Line #{@line_number}: expected code block to follow pattern")
+        end
+        code_id = @code_id
+        @code_id += 1
+        @patterns << Pattern.new(pattern: pattern, line_number: @line_number, code: code, code_id: code_id)
+      end
+    end
+
     def parse_pattern!
       if md = consume!(%r{/})
         pattern = ""

lib/propane/lexer.rb

@@ -19,8 +19,10 @@ class Propane
             TOKEN_NONE
           elsif state.accepts.drop?
             TOKEN_DROP
-          else
+          elsif state.accepts.token
             state.accepts.token.id
+          else
+            TOKEN_NONE
           end
         code_id =
           if state.accepts && state.accepts.code_id