move compiler to bosl and get first test working (adjusting syntax as i go)

lib/bosl/compiler/function_expression.rb

@@ -0,0 +1,37 @@
+module Bosl
+  module Compiler
+#    function attr_reader  :name, :params, :body , :receiver
+    def self.compile_function  expression, method
+      return_type , name , parameters, kids = *expression
+      name =  name.to_a.first
+      args = parameters.to_a.collect do |p|
+        raise "error, argument must be a identifier, not #{p}" unless p.type == :field
+        p[2]
+      end
+
+      if expression[:receiver]
+        # compiler will always return slot. with known value or not
+        r = Compiler.compile(expression.receiver, method )
+        if( r.value.is_a? Parfait::Class )
+          class_name = r.value.name
+        else
+          raise "unimplemented case in function #{r}"
+        end
+      else
+        r = Virtual::Self.new()
+        class_name = method.for_class.name
+      end
+      new_method = Virtual::MethodSource.create_method(class_name, name , args )
+      new_method.source.receiver = r
+      new_method.for_class.add_instance_method new_method
+
+      #frame = frame.new_frame
+      kids.to_a.each do |ex|
+        return_type = Compiler.compile(ex,new_method  )
+        raise return_type.inspect if return_type.is_a? Virtual::Instruction
+      end
+      new_method.source.return_type = return_type
+      Virtual::Return.new(return_type)
+    end
+  end
+end