mypy: Fix future syntax errors and other minor mistakes.

When we move to the Python 3 mypy syntax, we can't reference a class
before its definition.

tools/lib/api_tests.py

@@ -1,7 +1,6 @@
 
 if False:
-    from typing import Any
-    from api.zulip import Client
+    from zulip import Client
 
 def add_subscriptions(client):
     # type: (Client) -> None

tools/lib/css_parser.py

@@ -71,7 +71,7 @@ def get_whitespace_and_comments(tokens, i, end, line=None):
 
 
 def parse_sections(tokens, start, end):
-    # type: (List[Token], int, int) -> CssSectionList
+    # type: (List[Token], int, int) -> 'CssSectionList'
     i = start
     sections = []
     while i < end:
@@ -101,7 +101,7 @@ def parse_sections(tokens, start, end):
     return section_list
 
 def parse_section(tokens, start, end, pre_fluff, post_fluff):
-    # type: (List[Token], int, int, str, str) -> Union[CssNestedSection, CssSection]
+    # type: (List[Token], int, int, str, str) -> Union['CssNestedSection', 'CssSection']
     assert not ws(tokens[start].s)
     assert tokens[end-1].s == '}'  # caller should strip trailing fluff
 
@@ -130,7 +130,7 @@ def parse_section(tokens, start, end, pre_fluff, post_fluff):
         return section
 
 def parse_selectors_section(tokens, start, end):
-    # type: (List[Token], int, int) -> Tuple[int, CssSelectorList]
+    # type: (List[Token], int, int) -> Tuple[int, 'CssSelectorList']
     start, pre_fluff = get_whitespace_and_comments(tokens, start, end)
     assert pre_fluff == ''
     i = start
@@ -143,7 +143,7 @@ def parse_selectors_section(tokens, start, end):
     return i, selector_list
 
 def parse_selectors(tokens, start, end):
-    # type: (List[Token], int, int) -> CssSelectorList
+    # type: (List[Token], int, int) -> 'CssSelectorList'
     i = start
     selectors = []
     while i < end:
@@ -190,7 +190,7 @@ def parse_selector(tokens, start, end):
     return selector
 
 def parse_declaration_block(tokens, start, end):
-    # type: (List[Token], int, int) -> CssDeclarationBlock
+    # type: (List[Token], int, int) -> 'CssDeclarationBlock'
     assert tokens[start].s == '{'  # caller should strip leading fluff
     assert tokens[end-1].s == '}'  # caller should strip trailing fluff
     i = start + 1
@@ -212,7 +212,7 @@ def parse_declaration_block(tokens, start, end):
     return declaration_block
 
 def parse_declaration(tokens, start, end):
-    # type: (List[Token], int, int) -> CssDeclaration
+    # type: (List[Token], int, int) -> 'CssDeclaration'
     i, pre_fluff = get_whitespace_and_comments(tokens, start, end)
 
     if (i >= end) or (tokens[i].s == '}'):
@@ -241,7 +241,7 @@ def parse_declaration(tokens, start, end):
     return declaration
 
 def parse_value(tokens, start, end):
-    # type: (List[Token], int, int) -> CssValue
+    # type: (List[Token], int, int) -> 'CssValue'
     i, pre_fluff = get_whitespace_and_comments(tokens, start, end)
     if i < end:
         value = tokens[i]
@@ -353,7 +353,7 @@ def handle_postfluff(post_fluff, indent=False, space_after_first_line=False):
 
 class CssSectionList(object):
     def __init__(self, tokens, sections):
-        # type: (List[Token], List[Union[CssNestedSection, CssSection]]) -> None
+        # type: (List[Token], List[Union['CssNestedSection', 'CssSection']]) -> None
         self.tokens = tokens
         self.sections = sections
 
@@ -364,7 +364,7 @@ class CssSectionList(object):
 
 class CssNestedSection(object):
     def __init__(self, tokens, selector_list, section_list, pre_fluff, post_fluff):
-        # type: (List[Token], CssSelectorList, CssSectionList, str, str) -> None
+        # type: (List[Token], 'CssSelectorList', CssSectionList, str, str) -> None
         self.tokens = tokens
         self.selector_list = selector_list
         self.section_list = section_list
@@ -391,7 +391,7 @@ class CssNestedSection(object):
 
 class CssSection(object):
     def __init__(self, tokens, selector_list, declaration_block, pre_fluff, post_fluff):
-        # type: (List[Token], CssSelectorList, CssDeclarationBlock, str, str) -> None
+        # type: (List[Token], 'CssSelectorList', 'CssDeclarationBlock', str, str) -> None
         self.tokens = tokens
         self.selector_list = selector_list
         self.declaration_block = declaration_block
@@ -410,7 +410,7 @@ class CssSection(object):
 
 class CssSelectorList(object):
     def __init__(self, tokens, selectors):
-        # type: (List[Token], List[CssSelector]) -> None
+        # type: (List[Token], List['CssSelector']) -> None
         self.tokens = tokens
         self.selectors = selectors
 
@@ -433,7 +433,7 @@ class CssSelector(object):
 
 class CssDeclarationBlock(object):
     def __init__(self, tokens, declarations):
-        # type: (List[Token], List[CssDeclaration]) -> None
+        # type: (List[Token], List['CssDeclaration']) -> None
         self.tokens = tokens
         self.declarations = declarations
 
@@ -447,7 +447,7 @@ class CssDeclarationBlock(object):
 
 class CssDeclaration(object):
     def __init__(self, tokens, pre_fluff, post_fluff, css_property, css_value, semicolon):
-        # type: (List[Token], str, str, str, CssValue, bool) -> None
+        # type: (List[Token], str, str, str, 'CssValue', bool) -> None
         self.tokens = tokens
         self.pre_fluff = pre_fluff
         self.post_fluff = post_fluff

tools/lib/graph.py

@@ -20,7 +20,7 @@ class Graph(object):
             self.nodes.add(child)
 
     def copy(self):
-        # type: () -> Graph
+        # type: () -> 'Graph'
         return Graph(self.edges())
 
     def num_edges(self):
@@ -28,7 +28,7 @@ class Graph(object):
         return len(self.edges())
 
     def minus_edge(self, edge):
-        # type: (Edge) -> Graph
+        # type: (Edge) -> 'Graph'
         edges = self.edges().copy()
         edges.remove(edge)
         return Graph(edges)

tools/lib/html_branches.py

@@ -22,7 +22,7 @@ class HtmlTreeBranch(object):
     """
 
     def __init__(self, tags, fn):
-        # type: (List[TagInfo], Optional[str]) -> None
+        # type: (List['TagInfo'], Optional[str]) -> None
         self.tags = tags
         self.fn = fn
         self.line = tags[-1].token.line
@@ -189,8 +189,8 @@ def html_tag_tree(text):
 
 
 def build_id_dict(templates):
-    # type: (List[str]) -> (Dict[str,List[str]])
-    template_id_dict = defaultdict(list)  # type: (Dict[str,List[str]])
+    # type: (List[str]) -> (Dict[str, List[str]])
+    template_id_dict = defaultdict(list)  # type: (Dict[str, List[str]])
 
     for fn in templates:
         text = open(fn).read()