Clean up code

Also do some type hinting

Author: boriel

src/arch/zx48k/backend/__init__.py

@@ -4,7 +4,12 @@
 
 import math
 import re
+
+from collections import defaultdict
+
+from typing import Dict
 from typing import List
+from typing import Set
 
 from . import errors
 from .errors import InvalidICError as InvalidIC

src/symbols/arrayaccess.py

@@ -38,7 +38,7 @@ class SymbolARRAYACCESS(SymbolCALL):
     """
 
     def __init__(self, entry, arglist, lineno):
-        super(SymbolARRAYACCESS, self).__init__(entry, arglist, lineno)
+        super().__init__(entry, arglist, lineno)
         assert all(gl.BOUND_TYPE == x.type_.type_ for x in arglist), "Invalid type for array index"
 
     @property

src/symbols/call.py

@@ -36,15 +36,15 @@ class SymbolCALL(Symbol):
         lineno: source code line where this call was made
     """
 
-    def __init__(self, entry: SymbolFUNCTION, arglist: Iterable[SymbolARGUMENT], lineno: int):
-        super(SymbolCALL, self).__init__()
+    def __init__(self, entry: Symbol, arglist: Iterable[SymbolARGUMENT], lineno: int):
+        super().__init__()
         assert isinstance(lineno, int)
         assert all(isinstance(x, SymbolARGUMENT) for x in arglist)
         self.entry = entry
         self.args = arglist  # Func. call / array access
         self.lineno = lineno
 
-        if entry.token == 'FUNCTION':
+        if isinstance(entry, SymbolFUNCTION):
             for arg, param in zip(arglist, entry.params):  # Sets dependency graph for each argument -> parameter
                 if arg.value is not None:
                     arg.value.add_required_symbol(param)