Added docparse

sly/ast.py

@@ -0,0 +1,25 @@
+# sly/ast.py
+import sys
+
+class AST(object):
+    
+    @classmethod
+    def __init_subclass__(cls, **kwargs):
+        mod = sys.modules[cls.__module__]
+        if not hasattr(cls, '__annotations__'):
+            return
+
+        hints = list(cls.__annotations__.items())
+
+        def __init__(self, *args, **kwargs):
+            if len(hints) != len(args):
+                raise TypeError(f'Expected {len(hints)} arguments')
+            for arg, (name, val) in zip(args, hints):
+                if isinstance(val, str):
+                    val = getattr(mod, val)
+                if not isinstance(arg, val):
+                    raise TypeError(f'{name} argument must be {val}')
+                setattr(self, name, arg)
+
+        cls.__init__ = __init__
+

sly/docparse.py

@@ -0,0 +1,60 @@
+# docparse.py
+#
+# Support doc-string parsing classes
+
+__all__ = [ 'DocParseMeta' ]
+
+class DocParseMeta(type):
+    '''
+    Metaclass that processes the class docstring through a parser and
+    incorporates the result into the resulting class definition. This
+    allows Python classes to be defined with alternative syntax. 
+    To use this class, you first need to define a lexer and parser:
+
+        from sly import Lexer, Parser
+        class MyLexer(Lexer):
+           ...
+
+        class MyParser(Parser):
+           ...
+
+    You then need to define a metaclass that inherits from DocParseMeta.
+    This class must specify the associated lexer and parser classes.
+    For example:
+
+        class MyDocParseMeta(DocParseMeta):
+            lexer = MyLexer
+            parser = MyParser
+
+    This metaclass is then used as a base for processing user-defined
+    classes:
+
+        class Base(metaclass=MyDocParseMeta):
+            pass
+
+        class Spam(Base):
+            """
+            doc string is parsed
+            ...
+            """
+
+    It is expected that the MyParser() class would return a dictionary. 
+    This dictionary is used to create the final class Spam in this example.
+    '''
+
+    @staticmethod
+    def __new__(meta, clsname, bases, clsdict):
+        if '__doc__' in clsdict:
+            lexer = meta.lexer()
+            parser = meta.parser()
+            lexer.cls_name = parser.cls_name = clsname
+            lexer.cls_qualname = parser.cls_qualname = clsdict['__qualname__']
+            lexer.cls_module = parser.cls_module = clsdict['__module__']
+            parsedict = parser.parse(lexer.tokenize(clsdict['__doc__']))
+            assert isinstance(parsedict, dict), 'Parser must return a dictionary'
+            clsdict.update(parsedict)
+        return super().__new__(meta, clsname, bases, clsdict)
+
+    @classmethod
+    def __init_subclass__(cls):
+        assert hasattr(cls, 'parser') and hasattr(cls, 'lexer')