refact: use Python's Enum for classes

Author: boriel

src/api/constants.py

@@ -26,12 +26,13 @@
     os.path.abspath(os.path.dirname(os.path.abspath(__file__))), os.path.pardir)
 )
 
+
 # ----------------------------------------------------------------------
 # Class enums
 # ----------------------------------------------------------------------
 
-
-class CLASS:
+@enum.unique
+class CLASS(str, enum.Enum):
     """ Enums class constants
     """
     unknown = 'unknown'  # 0
@@ -41,35 +42,24 @@ class CLASS:
     label = 'label'  # 4 Labels
     const = 'const'  # 5  # constant literal value e.g. 5 or "AB"
     sub = 'sub'  # 6  # subroutine
-    type_ = 'type'  # 7  # type
-
-    _CLASS_NAMES = {
-        unknown: '(unknown)',
-        var: 'var',
-        array: 'array',
-        function: 'function',
-        label: 'label',
-        const: 'const',
-        sub: 'sub',
-        type_: 'type'
-    }
+    type = 'type'  # 7  # type
 
     @classproperty
     def classes(cls):
         return (cls.unknown, cls.var, cls.array, cls.function, cls.sub,
                 cls.const, cls.label)
 
     @classmethod
-    def is_valid(cls, class_):
+    def is_valid(cls, class_: Union[str, 'CLASS']):
         """ Whether the given class is
         valid or not.
         """
-        return class_ in cls.classes
+        return class_ in set(CLASS)
 
     @classmethod
-    def to_string(cls, class_):
+    def to_string(cls, class_: 'CLASS'):
         assert cls.is_valid(class_)
-        return cls._CLASS_NAMES[class_]
+        return class_.value
 
 
 class ARRAY:

src/api/symboltable.py

@@ -321,7 +321,7 @@ def entry_size(var_entry: Union[SymbolVAR, SymbolVARARRAY]):
         offset = 0
 
         for entry in entries:  # Symbols of the current level
-            if entry.class_ in (CLASS.function, CLASS.label, CLASS.type_):
+            if entry.class_ in (CLASS.function, CLASS.label, CLASS.type):
                 continue
 
             # Local variables offset
@@ -832,7 +832,7 @@ def check_labels(self):
         """ Checks if all the labels has been declared
         """
         for entry in self.labels:
-            self.check_is_declared(entry.name, entry.lineno, CLASS.label)
+            self.check_is_declared(entry.name, entry.lineno, CLASS.label.value)
 
     def check_classes(self, scope=-1):
         """ Check if pending identifiers are defined or not. If not,

src/symbols/type_.py

@@ -29,7 +29,7 @@ def __init__(self, name: str, lineno: int, *children):
         self.lineno = lineno  # The line the type was defined. Line 0 = basic type
         self.final = self  # self.final always return the original aliased type (if this type is an alias)
         self.caseins = OPTIONS.case_insensitive  # Whether this ID is case insensitive or not
-        self.class_ = CLASS.type_
+        self.class_ = CLASS.type
         self.accessed = False  # Whether this type has been used or not
 
     def __repr__(self):