Handle boxing ternary operators

They list two operators. We just need the first of these in "tokens".

Author: rocky

mathics_scanner/tokeniser.py

@@ -210,11 +210,17 @@ def init_module():
         ("VerticalSeparator", r" \uF432 "),
     ]
 
-    for table in ("box-operators", "no-meaning-infix-operators"):
-        table_info = OPERATOR_DATA[table]
+    for table_name in ("box-operators", "no-meaning-infix-operators"):
+        table_info = OPERATOR_DATA[table_name]
         for operator_name, unicode in table_info.items():
-            if any([tup[0] == operator_name for tup in tokens]):
-                print(f"Please remove {operator_name}")
+            # if any([tup[0] == operator_name for tup in tokens]):
+            #     print(f"Please remove {operator_name}")
+
+            # Ternary operators have two character symbols
+            # in a list. For tokens, we just want the first
+            # of the pair
+            if isinstance(unicode, list):
+                unicode = unicode[0]
             tokens.append((operator_name, f" {unicode} "))
 
     literal_tokens = {
@@ -264,14 +270,14 @@ def init_module():
             "FormBox",
             "FractionBox",
             "InterpretedBox",
-            "OverunderscriptBox",
             "OverscriptBox",
             "RadicalBox",
             "RawBackslash",
             "SqrtBox",
             "SubscriptBox",
             "SuperscriptBox",
             "UnderscriptBox",
+            "UnderoverscriptBox",
         ],
         "]": ["RawRightBracket"],
         "^": ["UpSetDelayed", "UpSet", "Power"],