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

lib/bosl/compiler/callsite_expression.rb

@@ -0,0 +1,36 @@
+module Bosl
+  module Compiler
+  # operators are really function calls
+
+#    call_site - attr_reader  :name, :args , :receiver
+
+    def self.compile_call expession , method
+      name , arguments , receiver = *expession
+      name = name.to_a.first
+
+      me = Compiler.compile( receiver.to_a.first , method )
+
+      ## need two step process, compile and save to frame
+      # then move from frame to new message
+      method.source.add_code Virtual::NewMessage.new
+      method.source.add_code Virtual::Set.new( me , Virtual::NewSelf.new(me.type))
+      method.source.add_code Virtual::Set.new( name.to_sym , Virtual::NewMessageName.new())
+      compiled_args = []
+      arguments.to_a.each_with_index do |arg , i|
+        #compile in the running method, ie before passing control
+        val = Compiler.compile( arg , method)
+        # move the compiled value to it's slot in the new message
+        # + 1 as this is a ruby 0-start , but 0 is the last message ivar.
+        # so the next free is +1
+        to = Virtual::NewArgSlot.new(i + 1 ,val.type , val)
+        # (doing this immediately, not after the loop, so if it's a return it won't get overwritten)
+        method.source.add_code Virtual::Set.new( val , to )
+        compiled_args << to
+      end
+      method.source.add_code Virtual::MessageSend.new(name , me , compiled_args) #and pass control
+      # the effect of the method is that the NewMessage Return slot will be filled, return it
+      # (this is what is moved _inside_ above loop for such expressions that are calls (or constants))
+      Virtual::Return.new( method.source.return_type )
+    end
+  end
+end