assemble module: move functions into Assembler class

Author: ThomasWaldmann

esp32_ulp/__main__.py

@@ -1,13 +1,14 @@
 import sys
 
-from .assemble import assemble
+from .assemble import Assembler
 
 
 def main(fn):
     with open(fn) as f:
         lines = f.readlines()
 
-    symbols, code = assemble(lines)
+    assembler = Assembler()
+    symbols, code = assembler.assemble(lines)
 
     print('Symbols:')
     for name, value in sorted(symbols.items()):

esp32_ulp/assemble.py

@@ -4,60 +4,62 @@
 
 from . import opcodes
 
+class Assembler:
+    def __init__(self):
+        self.symbols = {}
+        self.code = []
+        self.addr = 0
 
-def parse_line(line):
-    """
-    parse one line of assembler into label, opcode, args
-
-    a line looks like (label, opcode, args, comment are all optional):
-
-    label:    opcode arg1, arg2, ...    # rest-of-line comment
-    """
-    line = line.split('#', 1)[0].rstrip()
-    if not line:
-        return
-    has_label = line[0] not in '\t '
-    if has_label:
-        label_line = line.split(None, 1)
-        if len(label_line) == 2:
-            label, line = label_line
-        else:  # 1
-            label, line = label_line[0], None
-        label = label.rstrip(':')
-    else:
-        label, line = None, line.lstrip()
-    if line is None:
-        opcode, args = None, ()
-    else:
-        opcode_args = line.split(None, 1)
-        if len(opcode_args) == 2:
-            opcode, args = opcode_args
-            args = tuple(arg.strip() for arg in args.split(','))
-        else:  # 1
-            opcode, args = opcode_args[0], ()
-    return label, opcode, args
-
-
-def parse(lines):
-    parsed = [parse_line(line) for line in lines]
-    return [p for p in parsed if p is not None]
-
-
-def assemble(lines):
-    symbols = {}
-    code = []
-    addr = 0
-    for label, opcode, args in parse(lines):
-        if label is not None:
-            if label in symbols:
-                raise Exception('label %s is already defined.' % label)
-            symbols[label] = addr
-        if opcode is not None:
-            func = getattr(opcodes, 'i_' + opcode, None)
-            if func is None:
-                raise Exception('Unknown opcode: %s' % opcode)
-            instruction = func(*args)
-            code.append(instruction)
-            addr += 1
-    return symbols, code
+    def parse_line(self, line):
+        """
+        parse one line of assembler into label, opcode, args
+
+        a line looks like (label, opcode, args, comment are all optional):
+
+        label:    opcode arg1, arg2, ...    # rest-of-line comment
+        """
+        line = line.split('#', 1)[0].rstrip()
+        if not line:
+            return
+        has_label = line[0] not in '\t '
+        if has_label:
+            label_line = line.split(None, 1)
+            if len(label_line) == 2:
+                label, line = label_line
+            else:  # 1
+                label, line = label_line[0], None
+            label = label.rstrip(':')
+        else:
+            label, line = None, line.lstrip()
+        if line is None:
+            opcode, args = None, ()
+        else:
+            opcode_args = line.split(None, 1)
+            if len(opcode_args) == 2:
+                opcode, args = opcode_args
+                args = tuple(arg.strip() for arg in args.split(','))
+            else:  # 1
+                opcode, args = opcode_args[0], ()
+        return label, opcode, args
+
+
+    def parse(self, lines):
+        parsed = [self.parse_line(line) for line in lines]
+        return [p for p in parsed if p is not None]
+
+
+    def assemble(self, lines):
+        for label, opcode, args in self.parse(lines):
+            if label is not None:
+                if label in self.symbols:
+                    raise Exception('label %s is already defined.' % label)
+                self.symbols[label] = self.addr
+            if opcode is not None:
+                func = getattr(opcodes, 'i_' + opcode, None)
+                if func is None:
+                    raise Exception('Unknown opcode: %s' % opcode)
+                instruction = func(*args)
+                self.code.append(instruction)
+                self.addr += 1
+        return self.symbols, self.code
 

tests/assemble.py

@@ -1,4 +1,4 @@
-from esp32_ulp.assemble import parse_line, parse, assemble
+from esp32_ulp.assemble import Assembler
 
 src = """\
 # line 1
@@ -14,28 +14,31 @@
 
 
 def test_parse_line():
+    a = Assembler()
     lines = src.splitlines()
     # note: line number = index + 1
-    assert parse_line(lines[0]) == None
-    assert parse_line(lines[1]) == None
-    assert parse_line(lines[2]) == ('start', 'wait', ('42', ))
-    assert parse_line(lines[3]) == None
-    assert parse_line(lines[4]) == None
-    assert parse_line(lines[5]) == (None, 'ld', ('r0', 'r1', '0', ))
-    assert parse_line(lines[6]) == (None, 'st', ('r0', 'r1', '0', ))
-    assert parse_line(lines[7]) == (None, 'halt', ())
-    assert parse_line(lines[8]) == ('end', None, ())
+    assert a.parse_line(lines[0]) == None
+    assert a.parse_line(lines[1]) == None
+    assert a.parse_line(lines[2]) == ('start', 'wait', ('42', ))
+    assert a.parse_line(lines[3]) == None
+    assert a.parse_line(lines[4]) == None
+    assert a.parse_line(lines[5]) == (None, 'ld', ('r0', 'r1', '0', ))
+    assert a.parse_line(lines[6]) == (None, 'st', ('r0', 'r1', '0', ))
+    assert a.parse_line(lines[7]) == (None, 'halt', ())
+    assert a.parse_line(lines[8]) == ('end', None, ())
 
 
 def test_parse():
+    a = Assembler()
     lines = src.splitlines()
-    result = parse(lines)
+    result = a.parse(lines)
     assert None not in result
 
 
 def test_assemble():
+    a = Assembler()
     lines = src.splitlines()
-    symbols, code = assemble(lines)
+    symbols, code = a.assemble(lines)
     assert {'start', 'end'} <= set(symbols)
     assert symbols['start'] == 0
     assert symbols['end'] == 4