Changes from Python 3.7 to Python 3.8

--- /home/docs/checkouts/readthedocs.org/user_builds/restrictedpython/checkouts/latest/docs/contributing/ast/python3_7.ast
+++ /home/docs/checkouts/readthedocs.org/user_builds/restrictedpython/checkouts/latest/docs/contributing/ast/python3_8.ast
@@ -1,15 +1,13 @@
--- Python 3.7 AST
--- ASDL's 7 builtin types are:
--- identifier, int, string, bytes, object, singleton, constant
---
--- singleton: None, True or False
--- constant can be None, whereas None means "no value" for object.
+-- Python 3.8 AST
+-- ASDL's 5 builtin types are:
+-- identifier, int, string, object, constant
 
-module Python version "3.7"
+module Python version "3.8"
 {
-    mod = Module(stmt* body)
+    mod = Module(stmt* body, type_ignore *type_ignores)
         | Interactive(stmt* body)
         | Expression(expr body)
+        | FunctionType(expr* argtypes, expr returns)
 
         -- not really an actual node but useful in Jython's typesystem.
         | Suite(stmt* body)
@@ -18,12 +16,14 @@
                        arguments args,
                        stmt* body,
                        expr* decorator_list,
-                       expr? returns)
+                       expr? returns,
+                       string? type_comment)
          | AsyncFunctionDef(identifier name,
                             arguments args,
                             stmt* body,
                             expr* decorator_list,
-                            expr? returns)
+                            expr? returns,
+                            string? type_comment)
 
          | ClassDef(identifier name,
                     expr* bases,
@@ -33,18 +33,18 @@
          | Return(expr? value)
 
          | Delete(expr* targets)
-         | Assign(expr* targets, expr value)
+         | Assign(expr* targets, expr value, string? type_comment)
          | AugAssign(expr target, operator op, expr value)
          -- 'simple' indicates that we annotate simple name without parens
          | AnnAssign(expr target, expr annotation, expr? value, int simple)
 
          -- use 'orelse' because else is a keyword in target languages
-         | For(expr target, expr iter, stmt* body, stmt* orelse)
-         | AsyncFor(expr target, expr iter, stmt* body, stmt* orelse)
+         | For(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment)
+         | AsyncFor(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment)
          | While(expr test, stmt* body, stmt* orelse)
          | If(expr test, stmt* body, stmt* orelse)
-         | With(withitem* items, stmt* body)
-         | AsyncWith(withitem* items, stmt* body)
+         | With(withitem* items, stmt* body, string? type_comment)
+         | AsyncWith(withitem* items, stmt* body, string? type_comment)
 
          | Raise(expr? exc, expr? cause)
          | Try(stmt* body, excepthandler* handlers, stmt* orelse, stmt* finalbody)
@@ -62,10 +62,11 @@
 
          -- XXX Jython will be different
          -- col_offset is the byte offset in the utf8 string the parser uses
-         attributes (int lineno, int col_offset)
+         attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)
 
          -- BoolOp() can use left & right?
     expr = BoolOp(boolop op, expr* values)
+         | NamedExpr(expr target, expr value)
          | BinOp(expr left, operator op, expr right)
          | UnaryOp(unaryop op, expr operand)
          | Lambda(arguments args, expr body)
@@ -86,14 +87,9 @@
          | Call(expr func,
                 expr* args,
                 keyword* keywords)
-         | Num(object n) -- a number as a PyObject.
-         | Str(string s) -- need to specify raw, unicode, etc?
          | FormattedValue(expr value, int? conversion, expr? format_spec)
          | JoinedStr(expr* values)
-         | Bytes(bytes s)
-         | NameConstant(singleton value)
-         | Ellipsis
-         | Constant(constant value)
+         | Constant(constant value, string? kind)
 
          -- the following expression can appear in assignment context
          | Attribute(expr value, identifier attr, expr_context ctx)
@@ -104,7 +100,7 @@
          | Tuple(expr* elts, expr_context ctx)
 
          -- col_offset is the byte offset in the utf8 string the parser uses
-         attributes (int lineno, int col_offset)
+         attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)
 
     expr_context = Load
                  | Store
@@ -153,17 +149,18 @@
     comprehension = (expr target, expr iter, expr* ifs, int is_async)
 
     excepthandler = ExceptHandler(expr? type, identifier? name, stmt* body)
-                    attributes (int lineno, int col_offset)
+                    attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)
 
-    arguments = (arg* args,
+    arguments = (arg* posonlyargs,
+                 arg* args,
                  arg? vararg,
                  arg* kwonlyargs,
                  expr* kw_defaults,
                  arg? kwarg,
                  expr* defaults)
 
-    arg = (identifier arg, expr? annotation)
-          attributes (int lineno, int col_offset)
+    arg = (identifier arg, expr? annotation, string? type_comment)
+          attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)
 
     -- keyword arguments supplied to call (NULL identifier for **kwargs)
     keyword = (identifier? arg, expr value)
@@ -172,4 +169,6 @@
     alias = (identifier name, identifier? asname)
 
     withitem = (expr context_expr, expr? optional_vars)
+
+    type_ignore = TypeIgnore(int lineno, string tag)
 }