Add suppport for [of S]? part in nth-child's arguments

[annbgn]

Closes #76.

[annbgn]

i know the tests will be failing, but since i promised to have an update today, here it is :)

[codecov]

Codecov Report

Merging #120 (44aeedd) into master (f1fcf2b) will decrease coverage by 0.54%.
The diff coverage is 96.18%.

@@            Coverage Diff             @@
##           master     #120      +/-   ##
==========================================
- Coverage   96.12%   95.58%   -0.55%     
==========================================
  Files           2        2              
  Lines         878      929      +51     
  Branches      153      166      +13     
==========================================
+ Hits          844      888      +44     
- Misses         18       23       +5     
- Partials       16       18       +2     

Impacted Files	Coverage Δ
cssselect/parser.py	96.10% <94.63%> (-0.96%)	⬇️
cssselect/xpath.py	94.67% <98.85%> (+0.07%)	⬆️

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[wRAR]

@annbgn @elacuesta do we still need anything else done here?

[annbgn]

do we still need anything else done here?

imho no
i undrafted this pr

[elacuesta]

This line rang a bell to me. With no other changes to the class, it means that the arguments argument is now expected to be formatted differently, which breaks backward compatibility. Consider the following diff:

diff --git cssselect/parser.py cssselect/parser.py
index 4351f07..48e7604 100644
--- cssselect/parser.py
+++ cssselect/parser.py
@@ -160,6 +160,7 @@ class FunctionalPseudoElement(object):
     def __init__(self, name, arguments):
         self.name = ascii_lower(name)
         self.arguments = arguments
+        print("arguments:", arguments)
 
     def __repr__(self):
         return "%s[::%s(%r)]" % (

Then at the current master branch (9edc6c3):

In [1]: from cssselect import parse

In [2]: p = parse("a::asdf(arg1)")
arguments: [<IDENT 'arg1' at 8>]

While at the current add_support_for_of_s_part_in_nth_child branch (058b6b5):

In [1]: from cssselect import parse

In [2]: p = parse("a::asdf(arg1)")
arguments: ([<IDENT 'arg1' at 8>], None)

Could you explain the rationale of this change? Thanks!

[annbgn]

You're right, the backward compatibility breaks, because I changed signature of method parse_arguments which is used both for functions and functional pseudo elements.
Now I splitted parsing arguments into separate methods, so nothing will break
Nice catch!