Drop Python 2.7, 3.5 support, add 3.6-3.9 for fluent.syntax (#161)

* Declare compat with current python version, drop 2.7, 3.5.

Also adjust testing matrix to that.

* Drop six

* Use pyugrade --py36-plus to modernize syntax.

* Update version number and CHANGELOG

Author: Pike

.github/workflows/fluent.syntax.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, pypy2, pypy3]
+        python-version: [3.6, 3.7, 3.8, 3.9, pypy3]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
@@ -35,7 +35,6 @@ jobs:
         run: |
           python -m pip install wheel
           python -m pip install --upgrade pip
-          python -m pip install six
       - name: Test
         working-directory: ./fluent.syntax
         run: |
@@ -47,7 +46,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
         with:
-          python-version: 3.7
+          python-version: 3.9
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip

fluent.syntax/CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## fluent.syntax 0.19 (TBD)
+
+  - Drop support for Python 2.7 and 3.5
+  - Add support for Python 3.6 through 3.9
+
 ## fluent.syntax 0.18.1 (September 15, 2020)
 
   - Fix serialization of multiline patterns starting with special characters. (#156)

fluent.syntax/fluent/syntax/ast.py

@@ -1,9 +1,6 @@
-# coding=utf-8
-from __future__ import unicode_literals
 import re
 import sys
 import json
-import six
 
 
 def to_json(value, fn=None):
@@ -44,7 +41,7 @@ def scalars_equal(node1, node2, ignored_fields):
     return node1 == node2
 
 
-class BaseNode(object):
+class BaseNode:
     """Base class for all Fluent AST nodes.
 
     All productions described in the ASDL subclass BaseNode, including Span and
@@ -125,7 +122,7 @@ class SyntaxNode(BaseNode):
     """Base class for AST nodes which can have Spans."""
 
     def __init__(self, span=None, **kwargs):
-        super(SyntaxNode, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.span = span
 
     def add_span(self, start, end):
@@ -134,7 +131,7 @@ def add_span(self, start, end):
 
 class Resource(SyntaxNode):
     def __init__(self, body=None, **kwargs):
-        super(Resource, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.body = body or []
 
 
@@ -145,7 +142,7 @@ class Entry(SyntaxNode):
 class Message(Entry):
     def __init__(self, id, value=None, attributes=None,
                  comment=None, **kwargs):
-        super(Message, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.value = value
         self.attributes = attributes or []
@@ -155,7 +152,7 @@ def __init__(self, id, value=None, attributes=None,
 class Term(Entry):
     def __init__(self, id, value, attributes=None,
                  comment=None, **kwargs):
-        super(Term, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.value = value
         self.attributes = attributes or []
@@ -164,7 +161,7 @@ def __init__(self, id, value, attributes=None,
 
 class Pattern(SyntaxNode):
     def __init__(self, elements, **kwargs):
-        super(Pattern, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.elements = elements
 
 
@@ -174,13 +171,13 @@ class PatternElement(SyntaxNode):
 
 class TextElement(PatternElement):
     def __init__(self, value, **kwargs):
-        super(TextElement, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.value = value
 
 
 class Placeable(PatternElement):
     def __init__(self, expression, **kwargs):
-        super(Placeable, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.expression = expression
 
 
@@ -191,7 +188,7 @@ class Expression(SyntaxNode):
 class Literal(Expression):
     """An abstract base class for literals."""
     def __init__(self, value, **kwargs):
-        super(Literal, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.value = value
 
     def parse(self):
@@ -206,7 +203,7 @@ def from_escape_sequence(matchobj):
                 return c
             codepoint = int(codepoint4 or codepoint6, 16)
             if codepoint <= 0xD7FF or 0xE000 <= codepoint:
-                return six.unichr(codepoint)
+                return chr(codepoint)
             # Escape sequences reresenting surrogate code points are
             # well-formed but invalid in Fluent. Replace them with U+FFFD
             # REPLACEMENT CHARACTER.
@@ -235,98 +232,98 @@ def parse(self):
 
 class MessageReference(Expression):
     def __init__(self, id, attribute=None, **kwargs):
-        super(MessageReference, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.attribute = attribute
 
 
 class TermReference(Expression):
     def __init__(self, id, attribute=None, arguments=None, **kwargs):
-        super(TermReference, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.attribute = attribute
         self.arguments = arguments
 
 
 class VariableReference(Expression):
     def __init__(self, id, **kwargs):
-        super(VariableReference, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
 
 
 class FunctionReference(Expression):
     def __init__(self, id, arguments, **kwargs):
-        super(FunctionReference, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.arguments = arguments
 
 
 class SelectExpression(Expression):
     def __init__(self, selector, variants, **kwargs):
-        super(SelectExpression, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.selector = selector
         self.variants = variants
 
 
 class CallArguments(SyntaxNode):
     def __init__(self, positional=None, named=None, **kwargs):
-        super(CallArguments, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.positional = [] if positional is None else positional
         self.named = [] if named is None else named
 
 
 class Attribute(SyntaxNode):
     def __init__(self, id, value, **kwargs):
-        super(Attribute, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.id = id
         self.value = value
 
 
 class Variant(SyntaxNode):
     def __init__(self, key, value, default=False, **kwargs):
-        super(Variant, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.key = key
         self.value = value
         self.default = default
 
 
 class NamedArgument(SyntaxNode):
     def __init__(self, name, value, **kwargs):
-        super(NamedArgument, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.name = name
         self.value = value
 
 
 class Identifier(SyntaxNode):
     def __init__(self, name, **kwargs):
-        super(Identifier, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.name = name
 
 
 class BaseComment(Entry):
     def __init__(self, content=None, **kwargs):
-        super(BaseComment, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.content = content
 
 
 class Comment(BaseComment):
     def __init__(self, content=None, **kwargs):
-        super(Comment, self).__init__(content, **kwargs)
+        super().__init__(content, **kwargs)
 
 
 class GroupComment(BaseComment):
     def __init__(self, content=None, **kwargs):
-        super(GroupComment, self).__init__(content, **kwargs)
+        super().__init__(content, **kwargs)
 
 
 class ResourceComment(BaseComment):
     def __init__(self, content=None, **kwargs):
-        super(ResourceComment, self).__init__(content, **kwargs)
+        super().__init__(content, **kwargs)
 
 
 class Junk(SyntaxNode):
     def __init__(self, content=None, annotations=None, **kwargs):
-        super(Junk, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.content = content
         self.annotations = annotations or []
 
@@ -336,14 +333,14 @@ def add_annotation(self, annot):
 
 class Span(BaseNode):
     def __init__(self, start, end, **kwargs):
-        super(Span, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.start = start
         self.end = end
 
 
 class Annotation(SyntaxNode):
     def __init__(self, code, arguments=None, message=None, **kwargs):
-        super(Annotation, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self.code = code
         self.arguments = arguments or []
         self.message = message

fluent.syntax/fluent/syntax/errors.py

@@ -1,6 +1,3 @@
-from __future__ import unicode_literals
-
-
 class ParseError(Exception):
     def __init__(self, code, *args):
         self.code = code

fluent.syntax/fluent/syntax/parser.py

@@ -1,4 +1,3 @@
-from __future__ import unicode_literals
 import re
 from . import ast
 from .stream import EOF, EOL, FluentParserStream
@@ -25,7 +24,7 @@ def decorated(self, ps, *args, **kwargs):
     return decorated
 
 
-class FluentParser(object):
+class FluentParser:
     """This class is used to parse Fluent source content.
 
     ``with_spans`` enables source information in the form of
@@ -469,7 +468,7 @@ def get_escape_sequence(self, ps):
 
         if next == '\\' or next == '"':
             ps.next()
-            return '\\{}'.format(next)
+            return f'\\{next}'
 
         if next == 'u':
             return self.get_unicode_escape_sequence(ps, next, 4)
@@ -485,10 +484,10 @@ def get_unicode_escape_sequence(self, ps, u, digits):
         for _ in range(digits):
             ch = ps.take_hex_digit()
             if not ch:
-                raise ParseError('E0026', '\\{}{}{}'.format(u, sequence, ps.current_char))
+                raise ParseError('E0026', f'\\{u}{sequence}{ps.current_char}')
             sequence += ch
 
-        return '\\{}{}'.format(u, sequence)
+        return f'\\{u}{sequence}'
 
     @with_span
     def get_placeable(self, ps):