abstractsmartset: add a default implementation for min and max This default implementation takes advantage of the fast iterator if available.

lazyset: drop now useless ascending/descending definition

lazyset: inherit the fastasc and fastdesc method from subset When the filtered subset has such methods, we can use them. It is implemented as properties to be able to quickly return None if no corresponding fastasc exists on the subset.

lazyset: split the iteration logic from the condition filtering logic So that the filter can be reused by `fastasc` or `fastdesc`.

spanset: do a single range check in __contains__ Now that `start <= end` is always true, we can simplify this function.

spanset: enforce the order lazily to gain `fastasc` and `fastdesc` methods Instead of having the direction of iteration enforced through the ordering of `start` and `end` attributes of spanset, we encode the iteration direction in an explicit attribute and always store start < end. The logic for sort and reverse has to be updated. The __iter__ is now based on the newly introduced `fastasc` and `fastdesc` methods. This will allow other code simplifications in the future.

abstractsmartset: document the `fastasc` and `fastdesc` attributes/methods See the in-line documentation for details. (This is the beginning of a massive overhaul of revset).

spanset: remove ascending/descending implementation We can rely on their implementation in abstractsmartset.

baseset: remove ascending/descending redefinition We can rely on the abstractsmartset implementation.

abstractsmartset: default implementation for `ascending` and `descending` These two methods are actually silly aliases for `sort()` and `sort(reverse=True)`. So we get that aliasing at the abstractsmartset level. We will slowly phase out all the custom implementations and eventually remove any mentions of it from the code.

revert: bring back usage of `subset & ps` in `parents` Changeset 95af98616aa7 switched the order of the operand of the "&" computation to work around an issue from repo-wide spanset. The need for a workaround has been alleviated by the introduction of `fullreposet`. So we restore it to normal. The benchmark shows no significant changes as expected. We also revert the bogus test change introduced by 95af98616aa7. The order is actually important.

color: update docstring for debug option 964dd1c491ca updated the format for the --color=debug option. This updates the documentation to match this new format.

color: document the possibility to colourise tabs in diffs This is a no-op change that simply suggests that tabs can be colourised, but defaults to no colour effects for tabs. This complements cset c343557a8442. Like the similar effects for phases from f8e2aebbb24c, we set the default effects to '' instead of None, so that this is a true noop change. Otherwise, the diff.tab effect would override (i.e. neutralise) the effect of the surrounding label.

contrib/synthrepo: walk a repo's directory structure during analysis Augments the analyze command to additionally walk the repo's current directory structure (or of any directory tree), counting how many files appear in which paths. This data is saved in the repo model to be used by synthesize, for creating an initial commit with many files. This change is aimed at developing, testing and measuring scaling improvements when importing/converting a large repository to mercurial.

contrib/synthrepo: generate initial repo contents using directory shape model Augments the synthesize command to use an additional parameter to the analyzed repo model: the number of files in each directory at a given snapshot. Before synthesizing history, an arbitrary number of files will be generated in a distribution matching the analyzed directory structure. Intended for developing, testing and measuring scaling improvements when importing/converting a large repository to Mercurial.