loxi_ir: Moved to its own package
to group ir and related functionality. Also introduce a dedicated
frontend_ir model, and adds a unit test
diff --git a/loxi_front_end/frontend_ir.py b/loxi_front_end/frontend_ir.py
new file mode 100644
index 0000000..a927f94
--- /dev/null
+++ b/loxi_front_end/frontend_ir.py
@@ -0,0 +1,141 @@
+# Copyright 2013, Big Switch Networks, Inc.
+#
+# LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
+# the following special exception:
+#
+# LOXI Exception
+#
+# As a special exception to the terms of the EPL, you may distribute libraries
+# generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
+# that copyright and licensing notices generated by LoxiGen are not altered or removed
+# from the LoxiGen Libraries and the notice provided below is (i) included in
+# the LoxiGen Libraries, if distributed in source code form and (ii) included in any
+# documentation for the LoxiGen Libraries, if distributed in binary form.
+#
+# Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
+#
+# You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
+# a copy of the EPL at:
+#
+# http://www.eclipse.org/legal/epl-v10.html
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# EPL for the specific language governing permissions and limitations
+# under the EPL.
+
+from generic_utils import find
+from collections import namedtuple
+
+# This module is represents the frontend IR.
+__all__ = [
+ 'OFInput',
+ 'OFClass',
+ 'OFDataMember',
+ 'OFTypeMember',
+ 'OFDiscriminatorMember',
+ 'OFLengthMember',
+ 'OFFieldLengthMember',
+ 'OFPadMember',
+ 'OFEnum',
+ 'OFEnumEntry'
+]
+
+"""
+One input file
+
+@param wire_versions Set of integer wire versions this file applies to
+@param classes List of OFClass objects in the same order as in the file
+@param enums List of Enum objects in the same order as in the file
+"""
+OFInput = namedtuple('OFInput', ['filename', 'wire_versions', 'classes', 'enums'])
+
+"""
+An OpenFlow class
+
+All compound objects like messages, actions, instructions, etc are
+uniformly represented by this class.
+
+The members are in the same order as on the wire.
+
+@param name
+@param superclass name of the super class
+@param members List of *Member objects
+@param params optional dictionary of parameters
+"""
+OFClass = namedtuple('OFClass', ['name', 'superclass', 'members', 'virtual', 'params'])
+
+"""
+Normal field
+
+@param name
+@param oftype C-like type string
+
+Example: packet_in.buffer_id
+"""
+OFDataMember = namedtuple('OFDataMember', ['name', 'oftype'])
+
+"""
+Field that declares that this is an abstract super-class and
+that the sub classes will be discriminated based on this field.
+E.g., 'type' is the discriminator member of the abstract superclass
+of_action.
+
+@param name
+"""
+OFDiscriminatorMember = namedtuple('OFDiscriminatorMember', ['name', 'oftype'])
+
+"""
+Field used to determine the type of an OpenFlow object
+
+@param name
+@param oftype C-like type string
+@param value Fixed type value
+
+Example: packet_in.type, flow_add._command
+"""
+OFTypeMember = namedtuple('OFTypeMember', ['name', 'oftype', 'value'])
+
+"""
+Field with the length of the containing object
+
+@param name
+@param oftype C-like type string
+
+Example: packet_in.length, action_output.len
+"""
+OFLengthMember = namedtuple('OFLengthMember', ['name', 'oftype'])
+
+"""
+Field with the length of another field in the containing object
+
+@param name
+@param oftype C-like type string
+@param field_name Peer field whose length this field contains
+
+Example: packet_out.actions_len (only usage)
+"""
+OFFieldLengthMember = namedtuple('OFFieldLengthMember', ['name', 'oftype', 'field_name'])
+
+"""
+Zero-filled padding
+
+@param length Length in bytes
+
+Example: packet_in.pad
+"""
+OFPadMember = namedtuple('OFPadMember', ['length'])
+
+"""
+An OpenFlow enumeration
+
+All values are Python ints.
+
+@param name
+@param entries List of OFEnumEntry objects in input order
+@params dict of optional params. Currently defined:
+ - wire_type: the low_level type of the enum values (uint8,...)
+"""
+OFEnum = namedtuple('OFEnum', ['name', 'entries', 'params'])
+OFEnumEntry = namedtuple('OFEnumEntry', ['name', 'value', 'params'])