Added a pre-class directive

History.txt

@@ -5,6 +5,7 @@
     disabled with the custom_initialize variable:
 
       %% custom_initialize = true
+  * Added a pre-class directive for adding class comments
 
 * Bug fixes
   * Hoe plugin now overwrites generated files

README.rdoc

@@ -183,6 +183,8 @@ Kpeg allows the following directives:
 
 header::
   Placed before any generated code
+pre-class::
+  Placed before the class definition to provide a class comment
 
 == Generating and running your parser
 

lib/kpeg/code_generator.rb

@@ -339,7 +339,13 @@ def output
         code << "\n"
       end
 
+      pre_class = @grammar.directives['pre-class']
+
       if @standalone
+        if pre_class
+          code << pre_class.action.strip
+          code << "\n"
+        end
         code << "class #{@name}\n"
 
         cp  = standalone_region("compiled_parser.rb")
@@ -351,6 +357,10 @@ def output
         code << cp  << "\n"
       else
         code << "require 'kpeg/compiled_parser'\n\n"
+        if pre_class
+          code << pre_class.action.strip
+          code << "\n"
+        end
         code << "class #{@name} < KPeg::CompiledParser\n"
       end
 

test/test_kpeg_code_generator.rb

@@ -1455,6 +1455,49 @@ def _root
     assert cg.parse("hello")
   end
 
+  def test_directive_pre_class
+    gram = KPeg.grammar do |g|
+      g.root = g.dot
+      g.directives['pre-class'] = g.action("\n# some comment\n")
+    end
+
+    str = <<-STR
+require 'kpeg/compiled_parser'
+
+# some comment
+class Test < KPeg::CompiledParser
+
+  # root = .
+  def _root
+    _tmp = get_byte
+    set_failed_rule :_root unless _tmp
+    return _tmp
+  end
+
+  Rules = {}
+  Rules[:_root] = rule_info("root", ".")
+end
+    STR
+
+    cg = KPeg::CodeGenerator.new "Test", gram
+
+    assert_equal str, cg.output
+
+    assert cg.parse("hello")
+  end
+
+  def test_directive_pre_class_standalone
+    gram = KPeg.grammar do |g|
+      g.root = g.dot
+      g.directives['pre-class'] = g.action("\n# some comment\n")
+    end
+
+    cg = KPeg::CodeGenerator.new "Test", gram
+    cg.standalone = true
+
+    assert_match %r%^# some comment%, cg.output
+  end
+
   def test_setup_actions
     gram = KPeg.grammar do |g|
       g.root = g.dot