remove H904

this is really an overreach on preference, and not something which
we should be machine enforcing.

Change-Id: Ia4dcaa58d33cc71c726f52a0e696e6702819e2de

HACKING.rst

@@ -20,7 +20,8 @@ Step 0
 General
 -------
 - [H903] Use only UNIX style newlines (``\n``), not Windows style (``\r\n``)
-- [H904] Wrap long lines in parentheses and not a backslash for line continuation.
+- It is prefered to wrap long lines in parentheses and not a backslash
+  for line continuation.
 - [H201] Do not write ``except:``, use ``except Exception:`` at the very least
 - [H101] Include your name with TODOs as in ``# TODO(yourname)``
 - Do not shadow a built-in or reserved word. Example::

hacking/checks/other.py

@@ -25,19 +25,3 @@ def hacking_no_cr(physical_line):
     pos = physical_line.find('\r')
     if pos != -1 and pos == (len(physical_line) - 2):
         return (pos, "H903: Windows style line endings not allowed in code")
-
-
-@core.flake8ext
-def hacking_no_backslash_line_continuation(logical_line, tokens):
-    r"""Wrap lines in parentheses and not a backslash for line continuation.
-
-    Okay: a = (5 +\n     6)
-    H904: b = 5 + \\\n    6
-    """
-    found = False
-    for token_type, text, start_index, stop_index, line in tokens:
-        if line.rstrip('\r\n').endswith('\\') and not found:
-            found = True
-            yield ((start_index[0], start_index[1]+len(line.strip())-1),
-                   "H904: Wrap long lines in parentheses instead of a "
-                   "backslash")

setup.cfg

@@ -54,7 +54,6 @@ flake8.extension =
     H801 = hacking.checks.git:OnceGitCheckCommitTitleBug
     H802 = hacking.checks.git:OnceGitCheckCommitTitleLength
     H903 = hacking.checks.other:hacking_no_cr
-    H904 = hacking.checks.other:hacking_no_backslash_line_continuation
 
 [build_sphinx]
 all_files = 1