Minor changes

2 files changed, 8 insertions, 5 deletions

diff --git a/mdpoly/__init__.py b/mdpoly/__init__.py
index 0c1576d..2c007d0 100644
--- a/mdpoly/__init__.py
+++ b/mdpoly/__init__.py
@@ -30,7 +30,7 @@ State = _State
 # ┗┻┛╹┗╸╹ ╹╹  ╹  ┗━╸╹┗╸┗━┛
 
 # FIXME: move out of this file
-class _FromHelpers:
+class FromHelpers:
     @classmethod
     def from_names(cls, comma_separated_names: str, strip: bool =True) -> Iterable[Self]:
         """ Generate scalar variables from comma separated list of names """
@@ -39,15 +39,16 @@ class _FromHelpers:
             names = map(str.strip, names)
         yield from map(cls, names)
 
-class Constant(_Const, _PolyRingExpr, _FromHelpers):
+
+class Constant(_Const, _PolyRingExpr, FromHelpers):
     """ Constant values """
 
 
-class Variable(_Var, _PolyRingExpr, _FromHelpers):
+class Variable(_Var, _PolyRingExpr, FromHelpers):
     """ Polynomial Variable """
 
 
-class Parameter(_Param, _PolyRingExpr):
+class Parameter(_Param, _PolyRingExpr, FromHelpers):
     """ Parameter that can be substituted """
 
 
diff --git a/mdpoly/abc.py b/mdpoly/abc.py
index 8783262..d7578ec 100644
--- a/mdpoly/abc.py
+++ b/mdpoly/abc.py
@@ -84,7 +84,7 @@ class Expr(ABC):
     def __iter__(self) -> Iterable[Expr]:
         yield from self.children()
 
-    # --- Methods ---
+    # --- Methods for polynomial expression ---
 
     @abstractmethod
     def to_repr(self, repr_type: type, state: State) -> tuple[Repr, State]:
@@ -95,6 +95,8 @@ class Expr(ABC):
         See also :py:class:`mdpoly.state.State`.
         """
 
+    # --- Methods for tree data structure ---
+
     def children(self) -> Sequence[Expr]:
         """ Iterate over the two nodes """
         return self.left, self.right