new label-slice syntax in format.py; switch to doctest

1 files changed, 37 insertions, 1 deletions

diff --git a/subv.py b/subv.py
index b53639d..146d544 100644
--- a/subv.py
+++ b/subv.py
@@ -1,6 +1,8 @@
 import re
 white = re.compile('[ \t\.\n]+')
 hex = re.compile(r'^\-?(0x)?[0-9a-f]+$')
+slice_re = re.compile(r'^([^\[]+)(?:\[(\d+):(\d+)\])?$')
+field_re = re.compile(r'^(imm|off)(\d+)$')
 
 # parsing
 
@@ -22,6 +24,26 @@ def parse_segment(line):
 def parse_label(line):
     return line[:-1]
 
+def parse_reference(part):
+    ref = part[0]
+    field = part[1]
+
+    label, hi, lo = slice_re.match(ref).groups()
+    mode, size = field_re.match(field).groups()
+    
+    ref = {
+        'label': label,
+        'mode': mode,
+        'size': int(size),
+        'meta': part[2:],
+    }
+
+    if hi is not None:
+        ref['hi'] = int(hi)
+        ref['lo'] = int(lo)
+
+    return ref
+
 def classify(line):
     if line == '':
         return 'empty'
@@ -71,7 +93,7 @@ def untag(part, expect=None):
 def format_part(part):
     if not is_lref(part):
         first = '{:02x}'.format(part[0])
-        part = (first,) + part[1:]
+        part = (first, *part[1:])
     return '/'.join([str(p) for p in part])
 
 def format_instr(inst, comment=None):
@@ -80,6 +102,10 @@ def format_instr(inst, comment=None):
         packed = packed + '  # ' + comment
     return packed
 
+def join_all(gen):
+    res = '\n'.join(gen)
+    return res
+
 import unittest
 class TestParsing(unittest.TestCase):
     def test_parse_part(self):
@@ -101,6 +127,16 @@ class TestParsing(unittest.TestCase):
         self.assertEqual(parse_part('label:suff/tag*'), ('label:suff', 'tag*'))
         self.assertEqual(parse_part('$label:suff/tag*'), ('$label:suff', 'tag*'))
 
+    def test_parse_reference(self):
+        self.assertEqual(
+            parse_reference(('lbl', 'imm32')),
+            { 'label': 'lbl', 'hi': None, 'lo': None, 'mode': 'imm', 'size': 32, 'meta': () }
+        )
+        self.assertEqual(
+            parse_reference(('x[11:0]', 'off12')),
+            { 'label': 'x', 'hi': 11, 'lo': 0, 'mode': 'off', 'size': 12, 'meta': () }
+        )
+
 class TestChecks(unittest.TestCase):
     def test_is_lref(self):
         self.assertTrue(is_lref(('hello',)))