Group expression documentation into subcategories

Groups the expression nodes into much smaller subcategories for improved
readablility.

Some nodes defined in the expression module were grouped with statements
because they made more sense there (from a documentation perspective).

This also adds a local table of contents to the top of the nodes page
which better reveals all of the subcategories.

It also exports and categorizes
`BaseAssignTargetExpression`/`BaseDelTargetExpression`. These nodes were
referenced in type annotations of other nodes, so they need to be
exported if only for documentation reasons.

docs/source/nodes.rst

@@ -10,7 +10,7 @@ syntax tree <https://greentreesnakes.readthedocs.io/en/latest/nodes.html>`_.
 CSTNode
 -------
 
-The base node type which all other nodes derrive from.
+The base node type which all other nodes derive from.
 
 .. autoclass:: libcst.CSTNode
 
@@ -26,68 +26,134 @@ Expressions
 
 Nodes that represent various expressions.
 
-.. autoclass:: libcst.Annotation
-.. autoclass:: libcst.Arg
-.. autoclass:: libcst.Asynchronous
-.. autoclass:: libcst.Attribute
-.. autoclass:: libcst.Await
-.. autoclass:: libcst.BaseComp
-.. autoclass:: libcst.BaseDict
-.. autoclass:: libcst.BaseDictElement
-.. autoclass:: libcst.BaseElement
 .. autoclass:: libcst.BaseExpression
-.. autoclass:: libcst.BaseFormattedStringContent
-.. autoclass:: libcst.BaseList
-.. autoclass:: libcst.BaseNumber
-.. autoclass:: libcst.BaseSet
-.. autoclass:: libcst.BaseString
+
+Names and Object Attributes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.Name
+.. autoclass:: libcst.Attribute
+
+Operations and Comparisons
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.UnaryOperation
 .. autoclass:: libcst.BinaryOperation
 .. autoclass:: libcst.BooleanOperation
-.. autoclass:: libcst.Call
 .. autoclass:: libcst.Comparison
 .. autoclass:: libcst.ComparisonTarget
+
+Control Flow
+^^^^^^^^^^^^
+
+.. autoclass:: libcst.Asynchronous
+.. autoclass:: libcst.Await
+.. autoclass:: libcst.Yield
+.. autoclass:: libcst.From
+.. autoclass:: libcst.IfExp
+
+Lambdas and Function Calls
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.Lambda
+.. autoclass:: libcst.Call
+.. autoclass:: libcst.Arg
+
+Literal Values
+^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.Ellipses
+
+Numbers
+'''''''
+
+.. autoclass:: libcst.BaseNumber
+.. autoclass:: libcst.Integer
+.. autoclass:: libcst.Float
+.. autoclass:: libcst.Imaginary
+
+Strings
+'''''''
+
+.. autoclass:: libcst.BaseString
+.. autoclass:: libcst.SimpleString
+.. autoclass:: libcst.ConcatenatedString
+
+Formatted Strings (f-strings)
+'''''''''''''''''''''''''''''
+
+.. autoclass:: libcst.FormattedString
+.. autoclass:: libcst.BaseFormattedStringContent
+.. autoclass:: libcst.FormattedStringText
+.. autoclass:: libcst.FormattedStringExpression
+
+Collections
+^^^^^^^^^^^
+
+Simple Collections
+''''''''''''''''''
+
+.. autoclass:: libcst.Tuple
+
+.. autoclass:: libcst.BaseList
+.. autoclass:: libcst.List
+
+.. autoclass:: libcst.BaseSet
+.. autoclass:: libcst.Set
+
+Simple Collection Elements
+''''''''''''''''''''''''''
+
+.. autoclass:: libcst.BaseElement
+.. autoclass:: libcst.Element
+.. autoclass:: libcst.StarredElement
+
+Dictionaries
+''''''''''''
+
+.. autoclass:: libcst.BaseDict
+.. autoclass:: libcst.Dict
+
+Dictionary Elements
+'''''''''''''''''''
+
+.. autoclass:: libcst.BaseDictElement
+.. autoclass:: libcst.DictElement
+.. autoclass:: libcst.StarredDictElement
+
+Comprehensions
+^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.BaseComp
+
+.. autoclass:: libcst.GeneratorExp
+.. autoclass:: libcst.ListComp
+.. autoclass:: libcst.SetComp
+.. autoclass:: libcst.DictComp
+
 .. autoclass:: libcst.CompFor
 .. autoclass:: libcst.CompIf
-.. autoclass:: libcst.ConcatenatedString
-.. autoclass:: libcst.Dict
-.. autoclass:: libcst.DictComp
-.. autoclass:: libcst.DictElement
-.. autoclass:: libcst.Element
-.. autoclass:: libcst.Ellipses
-.. autoclass:: libcst.ExtSlice
-.. autoclass:: libcst.Float
-.. autoclass:: libcst.FormattedString
-.. autoclass:: libcst.FormattedStringExpression
-.. autoclass:: libcst.FormattedStringText
-.. autoclass:: libcst.From
-.. autoclass:: libcst.GeneratorExp
-.. autoclass:: libcst.IfExp
-.. autoclass:: libcst.Imaginary
-.. autoclass:: libcst.Index
-.. autoclass:: libcst.Integer
-.. autoclass:: libcst.Lambda
-.. autoclass:: libcst.LeftCurlyBrace
-.. autoclass:: libcst.LeftParen
-.. autoclass:: libcst.LeftSquareBracket
-.. autoclass:: libcst.List
-.. autoclass:: libcst.ListComp
-.. autoclass:: libcst.Name
-.. autoclass:: libcst.Param
-.. autoclass:: libcst.Parameters
-.. autoclass:: libcst.ParamStar
-.. autoclass:: libcst.RightCurlyBrace
-.. autoclass:: libcst.RightParen
-.. autoclass:: libcst.RightSquareBracket
-.. autoclass:: libcst.Set
-.. autoclass:: libcst.SetComp
-.. autoclass:: libcst.SimpleString
-.. autoclass:: libcst.Slice
-.. autoclass:: libcst.StarredDictElement
-.. autoclass:: libcst.StarredElement
+
+Subscripts and Slices
+^^^^^^^^^^^^^^^^^^^^^
+
 .. autoclass:: libcst.Subscript
-.. autoclass:: libcst.Tuple
-.. autoclass:: libcst.UnaryOperation
-.. autoclass:: libcst.Yield
+.. autoclass:: libcst.Index
+.. autoclass:: libcst.Slice
+.. autoclass:: libcst.ExtSlice
+
+
+Parenthesis, Brackets, and Braces
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. autoclass:: libcst.LeftParen
+.. autoclass:: libcst.RightParen
+
+.. autoclass:: libcst.LeftSquareBracket
+.. autoclass:: libcst.RightSquareBracket
+
+.. autoclass:: libcst.LeftCurlyBrace
+.. autoclass:: libcst.RightCurlyBrace
 
 Statements
 ----------
@@ -136,16 +202,29 @@ Helper Nodes
 
 Nodes that are used by various statements to represent some syntax, but
 are not statements on their own and cannot be used outside of the statements
-they blong with.
+they belong with.
+
+.. Annotation is in the expression module for import-order reasons, it's
+   most-often used a a helper for statements (e.g. functions)
+.. autoclass:: libcst.Annotation
 
 .. autoclass:: libcst.AsName
 .. autoclass:: libcst.AssignTarget
+.. autoclass:: libcst.BaseAssignTargetExpression
+.. autoclass:: libcst.BaseDelTargetExpression
 .. autoclass:: libcst.Decorator
 .. autoclass:: libcst.Else
 .. autoclass:: libcst.ExceptHandler
 .. autoclass:: libcst.Finally
 .. autoclass:: libcst.ImportAlias
 .. autoclass:: libcst.NameItem
+
+.. Params are in the expression module for import-order reasons, but it makes
+   sense to group these closer to FunctionDef than with Lambda.
+.. autoclass:: libcst.Parameters
+.. autoclass:: libcst.Param
+.. autoclass:: libcst.ParamStar
+
 .. autoclass:: libcst.WithItem
 
 Statement Blocks

libcst/__init__.py

@@ -15,7 +15,9 @@ from libcst._nodes._expression import (
     Asynchronous,
     Attribute,
     Await,
+    BaseAssignTargetExpression,
     BaseComp,
+    BaseDelTargetExpression,
     BaseDict,
     BaseDictElement,
     BaseElement,
@@ -210,7 +212,9 @@ __all__ = [
     "Asynchronous",
     "Attribute",
     "Await",
+    "BaseAssignTargetExpression",
     "BaseComp",
+    "BaseDelTargetExpression",
     "BaseDict",
     "BaseDictElement",
     "BaseElement",