templater: port pad() to take keyword arguments This is another example where keyword arguments can be actually useful.

templater: add support for keyword arguments Unlike revset, function arguments are pre-processed in templater. That's why we need to define argspec per function. An argspec field looks somewhat redundant in @templatefunc definition as a name field contains human-readable list of arguments. I'll make function doc be built from argspec later. Ported separate() function as an example.

templater: add parsing rule for key-value pair Based on the revset implementation, 70a2082f855a. This patch also adjusts the test as '=' is now a valid token.

templater: adjust binding strengths to make room for key-value operator Changed as follows: - template ops (%, |): +10 - arithmetic ops: +1 (but "negate" should be greater than "%")

templater: sort token table by binding strength Just for readability.

templater: make _hybrid provide more list/dict-like methods So the JSON filter works.

templater: hide private variable of _hybrid

templater: remove __iter__() from _hybrid, resolve it explicitly The goal is to fix "{hybrid_obj|json}" output. A _hybrid object must act as a list or a dict as well as a generator of legacy template strings. Before, _hybrid.__iter__() was assigned for legacy template, which conflicted with list.__iter__() API. This patch drops _hybrid.__iter__() and makes stringify/flatten functions unwrap a generator instead.

templater: rewrite doc of _hybrid class as docstring

sortdict: fix .pop() to return a value My future patch will need it.