[Python] Improve type alias definitions (#3917)

Fixes #3902

This commit ensures to highlight `type` more context sensitively.

It may have the following meanings:

1. built-in `type()` function
2. type alias declaration keyword: `type Alias`
3. ordinary variable used in many data classes

The built-in function (1.) most likely appears in r-value expressions, such as

   `my_type = type(var)`

At beginning of statements this commit prefers scoping `type` as keyword (2.)
or variable (3.) as this is the most likely use case.

The implementation ensures to start `meta` scope of alias declarations at bol
as class or function declarations do.

Python/Python.sublime-syntax

@@ -149,7 +149,7 @@ variables:
     | getattr | globals | hasattr | hash | help | hex | id | input | isinstance
     | issubclass | iter | len | locals | map | max | min | next | oct | open
     | ord | pow | property | range | repr | reversed | round | setattr | sorted
-    | staticmethod | sum | super | type | vars | zip
+    | staticmethod | sum | super | type(?=\s*\() | vars | zip
     # Python 2 functions
     | apply | cmp | coerce | execfile | intern | raw_input | reduce | reload
     | unichr | xrange
@@ -1042,10 +1042,18 @@ contexts:
 ###[ TYPE DEFINITIONS ]#######################################################
 
   type-definitions:
-    - match: ^\s*(type)\b
+    - match: ^(?=\s*type\b)
+      branch_point: type-definitions
+      branch:
+        - type-definition
+        - type-definition-fallback
+
+  type-definition:
+    - meta_include_prototype: false
+    - match: \s*(type)\b
       captures:
         1: keyword.declaration.class.python
-      push:
+      set:
         - type-definition-meta
         - type-definition-value-assignment
         - type-parameter-list
@@ -1061,14 +1069,25 @@ contexts:
     - match: '{{identifier}}'
       scope: entity.name.type.alias.python
       pop: 1
-    - include: line-continuation-or-pop
+    - include: line-continuations
+    - match: (?=\S)
+      fail: type-definitions
 
   type-definition-value-assignment:
     - match: =
       scope: keyword.operator.assignment.python
       set: variable-annotation
     - include: line-continuation-or-pop
 
+  type-definition-fallback:
+    # Fallback context, used, if `type` doesn't seem to start a type alias
+    - match: (?={{path}}\s*\()
+      set:
+        - function-call-argument-list
+        - function-call-wrapper
+        - qualified-name-until-leaf
+    - include: generic-name
+
 ###[ TYPE PARAMETERS ]########################################################
 
   type-parameter-lists:

Python/tests/syntax_test_python.py

@@ -2248,8 +2248,8 @@ def method(arg: T):
 ##################
 
 type
-# <- meta.type-alias.python keyword.declaration.class.python
-#^^^ meta.type-alias.python keyword.declaration.class.python
+# <- meta.generic-name - keyword
+#^^^ meta.generic-name - keyword
 
 type Alias # [T: int] = list[T]
 # <- meta.type-alias.python keyword.declaration.class.python
@@ -2320,6 +2320,55 @@ def method(arg: T):
 #       ^ meta.generic-name.python
 #        ^ punctuation.section.brackets.end.python
 
+  type Alias
+# <- meta.type-alias.python
+#^^^^^^^^^^^ meta.type-alias.python
+# ^^^^ keyword.declaration.class.python
+#      ^^^^^ entity.name.type.alias.python
+
+type(data)
+# <- meta.function-call.identifier.python support.function.builtin.python
+#^^^ meta.function-call.identifier.python support.function.builtin.python
+#   ^^^^^^ meta.function-call.arguments.python
+#   ^ punctuation.section.arguments.begin.python
+#    ^^^^ meta.path.python meta.generic-name.python
+#        ^ punctuation.section.arguments.end.python
+
+type: Alias
+# <- meta.generic-name.python
+#^^^ meta.generic-name.python
+#   ^ punctuation.separator.annotation.python
+#     ^^^^^ meta.type.python meta.path.python meta.generic-name.python
+
+type = 10
+# <- meta.generic-name.python
+#^^^ meta.generic-name.python
+#    ^ keyword.operator.assignment.python
+#      ^^ meta.number.integer.decimal.python constant.numeric.value.python
+
+class Foo:
+    type: Alias
+#   ^^^^ meta.generic-name.python
+#       ^ punctuation.separator.annotation.python
+#         ^^^^^ meta.type.python meta.path.python meta.generic-name.python
+
+    type = 10
+#   ^^^^ meta.generic-name.python
+#        ^ keyword.operator.assignment.python
+#          ^^ meta.number.integer.decimal.python constant.numeric.value.python
+
+    def __init__(self, type: int):
+#                      ^^^^ variable.parameter.python
+        self.type = type
+#            ^^^^ meta.path.python meta.generic-name.python
+#                   ^^^^ meta.path.python meta.generic-name.python
+
+        self.me = type(type)
+#                 ^^^^ meta.function-call.identifier.python support.function.builtin.python
+#                     ^^^^^^ meta.function-call.arguments.python
+#                     ^ punctuation.section.arguments.begin.python
+#                      ^^^^ meta.path.python meta.generic-name.python
+#                          ^ punctuation.section.arguments.end.python
 
 ##################
 # Decorators