Skip to content

Commit

Permalink
Add checks for continuation line indentation, disabled by default. Cl…
Browse files Browse the repository at this point in the history 
…oses #64.
  • Loading branch information
@florentx
florentx committed May 29, 2012
2 parents b9f72b1 + 0cc907e commit fcc6c11
Show file tree
Hide file tree
Showing 6 changed files with 400 additions and 7 deletions.
4 changes: 4 additions & 0 deletions CHANGES.txt
View file
Expand Up @@ -5,6 +5,10 @@ Changelog
1.2 (UNRELEASED)
----------------

* Add E121 through E127 for continuation line indentation. These
checks are disabled by default. If you want to force all checks,
use switch ``--select=E,W``. Patch by Sam Vilain. (Issue #64)

* Add E721 for direct type comparisons. (Issue #47)

* Add E711 and E712 for comparisons to singletons. (Issue #46)
Expand Down
185 changes: 183 additions & 2 deletions pep8.py
View file
Expand Up @@ -111,7 +111,7 @@ def blank_lines(logical_line, blank_lines, indent_level, line_number)


DEFAULT_EXCLUDE = '.svn,CVS,.bzr,.hg,.git'
DEFAULT_IGNORE = 'E24'
DEFAULT_IGNORE = 'E12,E24'
MAX_LINE_LENGTH = 79

INDENT_REGEX = re.compile(r'([ \t]*)')
Expand Down Expand Up @@ -418,6 +418,187 @@ def indentation(logical_line, previous_logical, indent_char,
yield 0, "E113 unexpected indentation"


def continuation_line_indentation(logical_line, tokens, indent_level):
"""
Continuation lines should align wrapped elements either vertically using
Python's implicit line joining inside parentheses, brackets and braces, or
using a hanging indent.
When using a hanging indent the following considerations should be applied:
- there should be no arguments on the first line, and
- further indentation should be used to clearly distinguish itself as a
continuation line.
"""
first_line = tokens[0][2][0]
last_line = tokens[-1][3][0]
if first_line == last_line:
return

# indent_next tells us whether the next block is indented; assuming
# that it is indented by 4 spaces, then we should not allow 4-space
# indents on the final continuation line; in turn, some other
# indents are allowed to have an extra 4 spaces.
indent_next = logical_line.endswith(':')

depth = 0

parens = [] # for looking back to see where a bracket was opened
max_physical_line = 0
visual_min = [None] # visual indent columns by indent depth
rel_indent = [[0, 0]] # relative indents of physical lines
last_indent = None
last_backslash = []
# if options.verbose >= 3:
# print ">>> " + tokens[0][4],

for token in tokens:
token_type, text, start, end, orig_line = token
line = start[0] - first_line
while len(parens) - 1 < line:
parens.append([])

if line > 0:
if max_physical_line < line and not token_type in (
tokenize.NEWLINE, tokenize.NL):
# if depth > 0 and len(last_backslash) >= line and \
# last_backslash[line - 1] is not None:
# yield last_backslash[line - 1], \
# "E502 unnecessary continuation backslash"
# this is the beginning of a continuation line.
max_physical_line = line
last_indent = start
# if options.verbose >= 3:
# print "... " + orig_line,

# record the initial indent. if lines were missing (eg,
# multi-line strings) then pad the list out
while len(rel_indent) - 1 < line:
rel_indent.append(None)
rel_indent[line] = [depth, start[1] - indent_level]

if depth > 0:
# a bracket expression in a continuation line.

# first, find the line that it was opened on
open_line = None
for open_line in range(line - 1, -1, -1):
if len(parens[open_line]) > 0:
break
start_col, end_col = parens[open_line][-1]
hang = rel_indent[line][1] - rel_indent[open_line][1]
else:
# an unbracketed continuation line (ie, backslash)
start_col = 0
hang = rel_indent[line][1]

err = None
# check to see if visual indenting is active
min_indent = visual_min[depth]
if min_indent is not None:
if start[1] < min_indent:
err = (start, 'E126 continuation line '
'insufficiently indented for visual '
'indent; hanging indents should have no '
'arguments on the first line')

# for E121
eff_depth = depth
if token_type == tokenize.OP and text in ']})':
eff_depth -= 1

# check that this line is either visually indented vs
# the opening parens, or a hanging indent.
if start[1] == last_token_multiline:
# continuing right after a multiline string is OK
pass
elif start[1] == start_col:
# visual. fine.
pass
elif min_indent is not None:
over_indent = start[1] - end_col
if start[1] > end_col and not (
over_indent == 4 and indent_next):
err = (start, "E127 continuation line over-"
"indented for visual indent")
else:
# hanging indent.
if eff_depth != depth:
if hang != 0:
err = (
start, 'E121 lines starting with a '
'closing bracket should be indented '
"to match that of the opening "
"bracket's line"
)
elif (hang <= 0):
err = (start, 'E124 continuation line '
'missing indent or outdented')
elif (hang % 4):
err = (start, 'E122 continuation line not '
'indented on a 4-space boundary')
elif (hang > 4) and not (hang == 8 and indent_next):
err = (start, "E125 continuation line over-"
"indented")

if err:
# TODO Correctly yield successive errors
yield err
return

# keep track of bracket depth and look for visual indenting
if token_type == tokenize.OP and text in '([{':
visual_min.append(None)
depth += 1
assert(len(visual_min) == depth + 1)
if depth > 0:
visual_min[depth] = visual_min[depth - 1]
parens[line].append([start[1], end[1]])
# if options.verbose >= 4:
# print "bracket depth {d} seen, col {c}, visual min = {m}"\
# .format(
# d=depth,
# c=start[1],
# m=visual_min[depth],
# )
elif len(parens[line]) > 0 and token_type != tokenize.NL:
# text after an open parens starts visual indenting
if visual_min[depth] is None:
visual_min[depth] = start[1]
# if options.verbose >= 4:
# print "bracket depth {d} indent to {c}".format(
# d=depth,
# c=start[1],
# )

if token_type == tokenize.OP and text in ')]}':
depth -= 1
visual_min.pop()
for open_line in range(line, -1, -1):
if len(parens[open_line]) > 0:
parens[open_line].pop()
break
if len(parens[open_line]):
visual_min[depth] = parens[open_line][-1][1]

# exceptions that need to processed at the end of lines
if len(last_backslash) - 1 < line:
while len(last_backslash) < line:
last_backslash.append(None)
last_backslash.append(
(end[0], len(orig_line) - 2) if orig_line.endswith('\\\n')
else None
)

last_token_multiline = (end[1] if start[0] != end[0] else None)

if indent_next and rel_indent[-1][1] == 4:
yield (last_indent, "E123 statement with indented block ends "
"with continuation line indented by 4 spaces")


def whitespace_before_parameters(logical_line, tokens):
"""
Avoid extraneous whitespace in the following situations:
Expand Down Expand Up @@ -711,7 +892,7 @@ def explicit_line_join(logical_line, tokens):
Okay: aaa = [123,\n 123]
Okay: aaa = ("bbb "\n "ccc")
Okay: aaa = "bbb " \\n "ccc"
Okay: aaa = "bbb " \\n "ccc"
"""
newlines = tokenize.NEWLINE, tokenize.NL
prev_type = tokenize.NEWLINE
Expand Down

0 comments on commit fcc6c11

Please sign in to comment.