come_from_opt handles and/or precidence properly

main.py: give a better error message when file is not found.

uncompyle6/main.py

@@ -94,6 +94,11 @@ def main(in_base, out_base, files, codes, outfile=None,
 
     for filename in files:
         infile = os.path.join(in_base, filename)
+        if not os.path.exists(infile):
+            sys.stderr.write("File '%s' doesn't exist. Skipped\n"
+                             % infile)
+            continue
+
         # print (infile, file=sys.stderr)
 
         if of: # outfile was given as parameter

uncompyle6/parser.py

@@ -223,9 +223,16 @@ class PythonParser(GenericASTBuilder):
         list_iter ::= list_if_not
         list_iter ::= lc_body
 
+        # Zero or more COME_FROM
+        # loops can have this
         _come_from ::= _come_from COME_FROM
         _come_from ::=
 
+        # Zero or one COME_FROM
+        # And/or expressions have this
+        come_from_opt ::= COME_FROM
+        come_from_opt ::=
+
         list_if ::= expr jmp_false list_iter
         list_if_not ::= expr jmp_true list_iter
 
@@ -337,8 +344,8 @@ class PythonParser(GenericASTBuilder):
         _mklambda ::= mklambda
 
         or   ::= expr JUMP_IF_TRUE_OR_POP expr COME_FROM
-        or   ::= expr jmp_true expr _come_from
-        and  ::= expr jmp_false expr _come_from
+        or   ::= expr jmp_true expr come_from_opt
+        and  ::= expr jmp_false expr come_from_opt
         and  ::= expr JUMP_IF_FALSE_OR_POP expr COME_FROM
         and2 ::= _jump jmp_false COME_FROM expr COME_FROM