Make the "Method" scanner action a direct feature of the embedded Plex,...

Make the "Method" scanner action a direct feature of the embedded Plex, instead of hacking it back into the Lexicon with a stray import.
See GH-2831.

Cython/Compiler/Lexicon.py

@@ -16,8 +16,7 @@ IDENT = 'IDENT'
 def make_lexicon():
     from ..Plex import \
         Str, Any, AnyBut, AnyChar, Rep, Rep1, Opt, Bol, Eol, Eof, \
-        TEXT, IGNORE, State, Lexicon
-    from .Scanning import Method
+        TEXT, IGNORE, Method, State, Lexicon
 
     letter = Any("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_")
     nonzero_digit = Any("123456789")

Cython/Compiler/Scanning.pxd

@@ -9,11 +9,6 @@ cdef unicode any_string_prefix, IDENT
 cdef get_lexicon()
 cdef initial_compile_time_env()
 
-cdef class Method:
-    cdef object name
-    cdef dict kwargs
-    cdef readonly object __name__  # for tracing the scanner
-
 ## methods commented with '##' out are used by Parsing.py when compiled.
 
 @cython.final

Cython/Compiler/Scanning.py

@@ -51,25 +51,6 @@ pyx_reserved_words = py_reserved_words + [
 ]
 
 
-class Method(object):
-
-    def __init__(self, name, **kwargs):
-        self.name = name
-        self.kwargs = kwargs or None
-        self.__name__ = name  # for Plex tracing
-
-    def __call__(self, stream, text):
-        method = getattr(stream, self.name)
-        # self.kwargs is almost always unused => avoid call overhead
-        return method(text, **self.kwargs) if self.kwargs is not None else method(text)
-
-    def __copy__(self):
-        return self  # immutable, no need to copy
-
-    def __deepcopy__(self, memo):
-        return self  # immutable, no need to copy
-
-
 #------------------------------------------------------------------
 
 class CompileTimeScope(object):

Cython/Plex/Actions.pxd

 
 cdef class Action:
-  cdef perform(self, token_stream, text)
-  cpdef same_as(self, other)
+    cdef perform(self, token_stream, text)
+    cpdef same_as(self, other)
 
 cdef class Return(Action):
-  cdef object value
-  cdef perform(self, token_stream, text)
-  cpdef same_as(self, other)
+    cdef object value
+    cdef perform(self, token_stream, text)
+    cpdef same_as(self, other)
 
 cdef class Call(Action):
-  cdef object function
-  cdef perform(self, token_stream, text)
-  cpdef same_as(self, other)
+    cdef object function
+    cdef perform(self, token_stream, text)
+    cpdef same_as(self, other)
+
+cdef class Method(Action):
+    cdef object name
+    cdef dict kwargs
+    cdef readonly object __name__  # for tracing the scanner
 
 cdef class Begin(Action):
-  cdef object state_name
-  cdef perform(self, token_stream, text)
-  cpdef same_as(self, other)
+    cdef object state_name
+    cdef perform(self, token_stream, text)
+    cpdef same_as(self, other)
 
 cdef class Ignore(Action):
-  cdef perform(self, token_stream, text)
+    cdef perform(self, token_stream, text)
 
 cdef class Text(Action):
-  cdef perform(self, token_stream, text)
+    cdef perform(self, token_stream, text)

Cython/Plex/Actions.py

@@ -14,6 +14,12 @@ class Action(object):
     def same_as(self, other):
         return self is other
 
+    def __copy__(self):
+        return self  # immutable, no need to copy
+
+    def __deepcopy__(self, memo):
+        return self  # immutable, no need to copy
+
 
 class Return(Action):
     """
@@ -52,6 +58,26 @@ class Call(Action):
         return isinstance(other, Call) and self.function is other.function
 
 
+class Method(Action):
+    """
+    Plex action that calls a specific method on the token stream,
+    passing the matched text and any provided constant keyword arguments.
+    """
+
+    def __init__(self, name, **kwargs):
+        self.name = name
+        self.kwargs = kwargs or None
+        self.__name__ = name  # for Plex tracing
+
+    def perform(self, token_stream, text):
+        method = getattr(token_stream, self.name)
+        # self.kwargs is almost always unused => avoid call overhead
+        return method(text, **self.kwargs) if self.kwargs is not None else method(text)
+
+    def same_as(self, other):
+        return isinstance(other, Method) and self.name == other.name and self.kwargs == other.kwargs
+
+
 class Begin(Action):
     """
     Begin(state_name) is a Plex action which causes the Scanner to

Cython/Plex/__init__.py

@@ -28,7 +28,7 @@ see the attached docstrings for more information.
 # flake8: noqa:F401
 from __future__ import absolute_import
 
-from .Actions import TEXT, IGNORE, Begin
+from .Actions import TEXT, IGNORE, Begin, Method
 from .Lexicons import Lexicon, State
 from .Regexps import RE, Seq, Alt, Rep1, Empty, Str, Any, AnyBut, AnyChar, Range
 from .Regexps import Opt, Rep, Bol, Eol, Eof, Case, NoCase