Type Hinting Breaks Highlighting #234

Prerequisites

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  • Reproduced the problem in Safe Mode: http://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: http://flight-manual.atom.io/hacking-atom/sections/debugging/
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  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

When using mypy-style type hinting in python, the syntax highlighting gets confused and no longer correctly identifies strings and keywords.
See:

Steps to Reproduce

The following code was used to reproduce the above screenshot

"""An example of how highlighting with type hinting works
"""

def reg_fun(foo):
    """Syntax highlighting identifies strings
    """
    bar = foo + 1
    return bar

def my_fun(foo: float) -> None:
    """The syntax highlighting is now confused
    """
    bar = foo + 2
    return bar

def third_fun(foo):
    """The string is identified but the def word is wrong
    """
    bar = foo + 3
    return bar

Expected behavior: [What you expect to happen]

The highlighting should (best case) recognize the type hints, or (acceptable case) ignore them so that the highlighting works.

Actual behavior: [What actually happens]

When type hints are used, the type hinting no longer works.
It appears that the -> is a key element of this; if I remove this, syntax highlighting works as expected:

Reproduces how often: [What percentage of the time does it reproduce?]

Always

Versions

You can get this information from copy and pasting the output of atom --version and apm --version from the command line. Also, please include the OS and what version of the OS you're running.

$ atom --version
Atom    : 1.23.3
Electron: 1.6.15
Chrome  : 56.0.2924.87
Node    : 7.4.0

$ apm --version
apm  1.18.12
npm  3.10.10
node 6.9.5 x64
atom 1.23.3
python 3.6.4
git 2.16.1

Additional Information

Any additional information, configuration or data that might be necessary to reproduce the issue.