counter: use symbolic names for input pins, wait conditions, annotation rows

Replace magic numbers by symbolic references to (fixed and optional)
decoder input signals, .wait() conditions, as well as annotation rows.

Move some empty lines, to better reflect which code lines form groups of
similar activity ("blocks" that logically belong together).

diff --git a/decoders/counter/pd.py b/decoders/counter/pd.py
index 6dd8d918549dfe69a9117360f7410b262b5e9e72..696c8e9f4ec1c82d32918c69d28fccc65737ced6 100644 (file)
--- a/decoders/counter/pd.py
+++ b/decoders/counter/pd.py
@@ -19,6 +19,9 @@
 
 import sigrokdecode as srd
 
+(PIN_DATA, PIN_RESET) = range(2)
+(ROW_EDGE, ROW_WORD, ROW_RESET) = range(3)
+
 class Decoder(srd.Decoder):
     api_version = 3
     id = 'counter'
@@ -40,9 +43,9 @@ class Decoder(srd.Decoder):
         ('word_reset', 'Word reset'),
     )
     annotation_rows = (
-        ('edge_counts', 'Edges', (0,)),
-        ('word_counts', 'Words', (1,)),
-        ('word_resets', 'Word resets', (2,)),
+        ('edge_counts', 'Edges', (ROW_EDGE,)),
+        ('word_counts', 'Words', (ROW_WORD,)),
+        ('word_resets', 'Word resets', (ROW_RESET,)),
     )
     options = (
         {'id': 'data_edge', 'desc': 'Edges to count (data)', 'default': 'any',
@@ -77,23 +80,24 @@ class Decoder(srd.Decoder):
     def decode(self):
         opt_edge_map = {'rising': 'r', 'falling': 'f', 'any': 'e'}
 
-        condition = [{0: opt_edge_map[self.edge]}]
-
-        if self.has_channel(1):
-            self.have_reset = True
-            condition.append({1: opt_edge_map[self.options['reset_edge']]})
+        condition = [{PIN_DATA: opt_edge_map[self.edge]}]
+        self.have_reset = self.has_channel(PIN_RESET)
+        if self.have_reset:
+            cond_reset = len(condition)
+            condition.append({PIN_RESET: opt_edge_map[self.options['reset_edge']]})
 
         while True:
             self.wait(condition)
-            if self.have_reset and self.matched[1]:
+
+            if self.have_reset and self.matched[cond_reset]:
                 self.edge_count = 0
                 self.word_count = 0
-                self.putc(2, ['Word reset', 'Reset', 'Rst', 'R'])
+                self.putc(ROW_RESET, ['Word reset', 'Reset', 'Rst', 'R'])
                 continue
 
             self.edge_count += 1
+            self.putc(ROW_EDGE, [str(self.edge_count)])
 
-            self.putc(0, [str(self.edge_count)])
             if self.divider > 0 and (self.edge_count % self.divider) == 0:
                 self.word_count += 1
-                self.putc(1, [str(self.word_count)])
+                self.putc(ROW_WORD, [str(self.word_count)])