[rahul05ranjan]

What's wrong

The JSON5 grammar accepts a leading + on numbers (+Infinity was added in #63), but num_literal's + branch consumes the sign and returns the unsigned token alone — the - branch keeps its sign. So the parse_int / parse_float / parse_constant hooks receive a spelling that differs from the document, breaking the "passed the integer string as written" contract documented in loads()/parse() (and the as-written parse_constant semantics established around -NaN in #152/#157):

>>> json5.loads('+NaN', parse_constant=str)       # expected '+NaN'
'NaN'
>>> json5.loads('+Infinity', parse_constant=str)  # expected '+Infinity'
'Infinity'
>>> json5.loads('+0xff', parse_int=str)           # expected '+0xff'
'0xff'
>>> json5.loads('+5', parse_int=str)              # expected '+5'
'5'
>>> json5.loads('+1.5', parse_float=str)          # expected '+1.5'
'1.5'

The fix

• json5/json5.g: the + branch returns '+' + n, as the - branch does.
• json5/parser.py (generated): the same one-token change in _num_literal__c1_, mirroring _num_literal__c0_.
• json5/lib.py: _walk_ast's hex-prefix test and the default _parse_int helper strip either sign (v[:1] in ('-', '+') / s.lstrip('+-')) instead of only -, so a +0xff token reaches the hex branch and parses as 255 rather than falling through to base-10 int() and raising.
• tests/lib_test.py: assert the + spellings arrive at the hooks (+5, +0xff for parse_int; +1.5 for parse_float; +Infinity/+NaN for parse_constant) and +0xff → 255 as a value.

Values are unchanged everywhere (+1 → 1, +0xf → 15, +Infinity → inf all keep passing); only the hook spellings become as-written.

Verification

System python3, no dependencies beyond the package's own sources:

• Full upstream suite with the changes applied: python3 -m unittest discover -s tests → 80 tests OK (including the new + assertions).
• Pre-fix proof of the dropped sign, per hook (see A leading + sign is dropped from the number spelling before parse_int/parse_float/parse_constant see it #159 for the full transcript).
• Value battery: +5→5, +0xff→255, +0X2a→42, +.5→0.5, +1e3→1000.0, +Infinity→inf, +NaN→nan, plus -/unsigned forms unchanged.
• Error battery unchanged: + 5, ++5, +-5, +, +Infinit, +Nan still reject with the same messages.
• parser.py is generated code; the change mirrors the - branch's generated form exactly so it matches what a regeneration from the updated .g would produce.

Fixes #159

[dpranke]

Looks good, nice work :).

[rahul05ranjan]

Thanks for merging this one too — appreciate the quick turnaround on both!