gps.py: Improve setting the valid bits in O responses

Instead of checking each value twice for NaN, this commit integrates
setting the valid bit with the conversion in function default().

Is it correct that there's no valid bit for the track error (fix.epd)?

1 files changed, 27 insertions, 28 deletions

diff --git a/gps.py b/gps.py
index 01a48872..56c5e75b 100755
--- a/gps.py
+++ b/gps.py
@@ -306,47 +306,46 @@ class gps(gpsdata):
                         self.fix.mode = MODE_NO_FIX
                     else:
                         self.timings.sentence_tag = fields[0]
-                        def default(i, cnv=float):
+                        def default(i, vbit=0, cnv=float):
                             if fields[i] == '?':
                                 return NaN
                             else:
-                                return cnv(fields[i])
+                                try:
+                                    value = cnv(fields[i])
+                                except ValueError:
+                                    return NaN
+                                self.valid |= vbit
+                                return value
+                        # clear all valid bits that might be set again below
+                        self.valid &= ~(
+                            TIME_SET | TIMERR_SET | LATLON_SET | ALTITUDE_SET |
+                            HERR_SET | VERR_SET | TRACK_SET | SPEED_SET |
+                            CLIMB_SET | SPEEDERR_SET | CLIMBERR_SET | MODE_SET
+                        )
                         self.utc = fields[1]
-                        self.fix.time = default(1)
+                        self.fix.time = default(1, TIME_SET)
                         if not isnan(self.fix.time):
                             self.utc = isotime(self.fix.time)
-                        self.fix.ept = default(2)
-                        self.fix.latitude = default(3)
+                        self.fix.ept = default(2, TIMERR_SET)
+                        self.fix.latitude = default(3, LATLON_SET)
                         self.fix.longitude = default(4)
-                        self.fix.altitude = default(5)
-                        self.fix.eph = default(6)
-                        self.fix.epv = default(7)
-                        self.fix.track = default(8)
-                        self.fix.speed = default(9)
-                        self.fix.climb = default(10)
+                        self.fix.altitude = default(5, ALTITUDE_SET)
+                        self.fix.eph = default(6, HERR_SET)
+                        self.fix.epv = default(7, VERR_SET)
+                        self.fix.track = default(8, TRACK_SET)
+                        self.fix.speed = default(9, SPEED_SET)
+                        self.fix.climb = default(10, CLIMB_SET)
                         self.fix.epd = default(11)
-                        self.fix.eps = default(12)
-                        self.fix.epc = default(13)
+                        self.fix.eps = default(12, SPEEDERR_SET)
+                        self.fix.epc = default(13, CLIMBERR_SET)
                         if len(fields) > 14:
-                            self.fix.mode = default(14, int)
+                            self.fix.mode = default(14, MODE_SET, int)
                         else:
-                            if isnan(self.fix.altitude):
+                            if self.valid & ALTITUDE_SET:
                                 self.fix.mode = MODE_2D
                             else:
                                 self.fix.mode = MODE_3D
-                        self.valid = TIME_SET | TIMERR_SET | LATLON_SET | MODE_SET
-                        if self.fix.mode == MODE_3D:
-                            self.valid |= ALTITUDE_SET | CLIMB_SET
-                        if not isnan(self.fix.eph):
-                            self.valid |= HERR_SET
-                        if not isnan(self.fix.epv):
-                            self.valid |= VERR_SET
-                        if not isnan(self.fix.track):
-                            self.valid |= TRACK_SET | SPEED_SET
-                        if not isnan(self.fix.eps):
-                            self.valid |= SPEEDERR_SET
-                        if not isnan(self.fix.epc):
-                            self.valid |= CLIMBERR_SET
+                            self.valid |= MODE_SET
                 elif cmd == 'P':
                     (self.fix.latitude, self.fix.longitude) = map(float, data.split())
                     self.valid |= LATLON_SET