From 5e2dcf2100947f1414333375d623802b9417e128 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Ne=C4=8Dada?= <marek@necada.org>
Date: Thu, 15 Aug 2019 15:19:54 +0300
Subject: [PATCH] VSWFNorm IntFlag / IntEnum fallback

Former-commit-id: f1cc46f208bdceac972409836a238a56966277a4
---
 qpms/cybspec.pyx    | 36 +++++++++++++++++++++++++-----------
 qpms/qpms_cdefs.pxd |  1 +
 qpms/qpms_types.h   |  4 +++-
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/qpms/cybspec.pyx b/qpms/cybspec.pyx
index 7e6ad16..d3ff8bf 100644
--- a/qpms/cybspec.pyx
+++ b/qpms/cybspec.pyx
@@ -1,17 +1,31 @@
 import numpy as np
 import enum
 from .cycommon import get_mn_y, tlm2uvswfi
+__VSWF_norm_dict = {
+    'INVERSE' : QPMS_NORMALISATION_INVERSE,
+    'REVERSE_AZIMUTHAL_PHASE' : QPMS_NORMALISATION_REVERSE_AZIMUTHAL_PHASE,
+    'SPHARM_REAL' : QPMS_NORMALISATION_SPHARM_REAL,
+    'M_I' : QPMS_NORMALISATION_M_I,
+    'M_MINUS' : QPMS_NORMALISATION_M_MINUS,
+    'N_I' : QPMS_NORMALISATION_N_I,
+    'N_MINUS' : QPMS_NORMALISATION_N_MINUS,
+    'L_I' : QPMS_NORMALISATION_L_I,
+    'L_MINUS' : QPMS_NORMALISATION_L_MINUS,
+    'CSPHASE' : QPMS_NORMALISATION_CSPHASE,
+    'UNNORM' : QPMS_NORMALISATION_NORM_NONE,
+    'UNNORM_CS' : QPMS_NORMALISATION_NORM_NONE | QPMS_NORMALISATION_CSPHASE,
+    'POWERNORM' : QPMS_NORMALISATION_NORM_POWER,
+    'POWERNORM_CS' : QPMS_NORMALISATION_NORM_POWER | QPMS_NORMALISATION_CSPHASE,
+    'SPHARMNORM' : QPMS_NORMALISATION_NORM_SPHARM,
+    'SPHARMNORM_CS' : QPMS_NORMALISATION_NORM_SPHARM | QPMS_NORMALISATION_CSPHASE,
+    'UNDEF' : QPMS_NORMALISATION_UNDEF,
+    'DEFAULT' : QPMS_NORMALISATION_DEFAULT,
+}
 
-class VSWFNorm(enum.IntEnum):
-    # TODO try to make this an enum.IntFlag if supported
-    # TODO add the other flags from qpms_normalisation_t as well
-    UNNORM = QPMS_NORMALISATION_NORM_NONE
-    UNNORM_CS = QPMS_NORMALISATION_NORM_NONE | QPMS_NORMALISATION_CSPHASE
-    POWERNORM = QPMS_NORMALISATION_NORM_POWER
-    POWERNORM_CS = QPMS_NORMALISATION_NORM_POWER | QPMS_NORMALISATION_CSPHASE
-    SPHARMNORM = QPMS_NORMALISATION_NORM_SPHARM
-    SPHARMNORM_CS = QPMS_NORMALISATION_NORM_SPHARM | QPMS_NORMALISATION_CSPHASE
-    UNDEF = QPMS_NORMALISATION_UNDEF
+try:
+    VSWFNorm = enum.IntFlag('VSWFNorm', names=__VSWF_norm_dict, module=__name__)
+except AttributeError: # For older Python versions, use IntEnum instead
+    VSWFNorm = enum.IntEnum('VSWFNorm', names=__VSWF_norm_dict, module=__name__)
 
 cdef class BaseSpec:
     '''Cython wrapper over qpms_vswf_set_spec_t.
@@ -50,7 +64,7 @@ cdef class BaseSpec:
         if 'norm' in kwargs.keys():
             self.s.norm = kwargs['norm']
         else:
-            self.s.norm = <qpms_normalisation_t>(QPMS_NORMALISATION_NORM_POWER | QPMS_NORMALISATION_CSPHASE)
+            self.s.norm = <qpms_normalisation_t>(QPMS_NORMALISATION_DEFAULT)
         # set the other metadata
         cdef qpms_l_t l
         self.s.lMax_L = -1
diff --git a/qpms/qpms_cdefs.pxd b/qpms/qpms_cdefs.pxd
index 9d7378a..2474e20 100644
--- a/qpms/qpms_cdefs.pxd
+++ b/qpms/qpms_cdefs.pxd
@@ -56,6 +56,7 @@ cdef extern from "qpms_types.h":
         QPMS_NORMALISATION_CONVENTION_KRISTENSSON_REAL
         QPMS_NORMALISATION_CONVENTION_KRISTENSSON
         QPMS_NORMALISATION_CONVENTION_SCUFF
+        QPMS_NORMALISATION_DEFAULT
     ctypedef enum qpms_bessel_t:
         QPMS_BESSEL_REGULAR
         QPMS_BESSEL_SINGULAR
diff --git a/qpms/qpms_types.h b/qpms/qpms_types.h
index 4d7955f..fd73ce0 100644
--- a/qpms/qpms_types.h
+++ b/qpms/qpms_types.h
@@ -158,7 +158,9 @@ typedef enum {
 	/// VSWF convention used in SCUFF-EM \cite reid_electromagnetism_2016
 	QPMS_NORMALISATION_CONVENTION_SCUFF = QPMS_NORMALISATION_NORM_POWER
 		| QPMS_NORMALISATION_CSPHASE | QPMS_NORMALISATION_M_I
-		| QPMS_NORMALISATION_N_MINUS
+		| QPMS_NORMALISATION_N_MINUS,
+	/// Default VSWF convention. We might encourage the compiler to expect this one.
+	QPMS_NORMALISATION_DEFAULT = QPMS_NORMALISATION_CONVENTION_KRISTENSSON
 } qpms_normalisation_t;
 
 /// Determine whether the convention includes Condon-Shortley phase (-1) or not (+1).