There's a subtle difference between
- 'expression = { whitespace* ... whitespace* }', and
- '_{ whitespace* ~ expression ~ whitespace* }'.
The former includes surrounding whitespace in an "expression", the latter
doesn't. This affects the span of error indication.
Suggested by @arxanas.
Actually, it's easier to support these infix ops than erroring out, but I
don't want to make revset syntax more cryptic. "x- y" can't be handled by
this rule because "x-" is parsed as a parents expression.
Because a unary negation node '~y' is more primitive than the corresponding
difference node 'x~y', '~y' is easier to deal with while rewriting the tree.
That's the main reason to add RevsetExpression::NotIn node.
As we have a NotIn node, it makes sense to add an operator for that. This
patch reuses '~' token, which I feel intuitive since the other set operators
looks like bitwise ops. Another option is '!'.
The unary '~' operator has the highest precedence among the set operators,
but they are lower than the ranges. This might be counter intuitive, but
useful because a prefix range ':x' can be negated without parens.
Maybe we can remove the redundant infix operator 'x ~ y', but it isn't
decided yet.
Function parameters are processed as local symbols while substituting
alias expression. This isn't as efficient as Mercurial which caches
a tree of fully-expanded function template, but that wouldn't matter in
practice.
Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
The CLI will load aliases from config, insert them one by one, and warn if
declaration part is invalid. That's why RevsetAliasesMap is a public struct
and needs to be instantiated by the caller.
I'm thinking of adding alias expansion at this stage, and it would be a bit
tedious to pass around mutable context by function parameter. So let's reduce
the number of the intermediate functions.
This also produces a better error message.
Previously an expression 'foo-bar-' failed to parse because
1. try first rule: 'foo-bar-' matches (identifier_part+ ~ '-')+, but the
trailing '' doesn't match identifier_part+
2. fall back to second rule: 'foo' matches identifier_part+
=> (identifier 'foo')
Instead, we need to consume as much (identifier_part ~ '-' ~ ...) as possible
before falling back to the identifier_part rule.
I think the trailing + of identifier_part+ is redundant, so removed it as
well.
It makes sense to omit either of the arguments of the `..` operator,
even though `..x` is equivalent to `:x`. `x..`, with a implied right
argument of `heads()` is more useful.
This lets you use the same operator as we currently have for ancestors
and descendants (`,,`) to also specify a DAG range. That's what
Mercurial uses the `::` operator for and what Git has `git log
--ancestry-path` for.
I really liked the idea of having the operators for parents and
ancestors (etc.) look similar, but that turned out to be problematic
when we want to add an infix operator for a DAG range (hg's `::`
revset operator and git's `--ancestry-path` flag). Let's say we chose
`:*:` as the operator. Part of the problem is how to parse `foo:*:bar`
without eagerly parsing the `foo:`. It would also be nicer to use
exactly the same operator as prefix, postfix, and infix. Since the
"parents" operator can be repeated, we can't have it be just `:` and
the "ancestors" operator be `::`. We could make the "ancestors"
operator be something like `*:*` (or anything symmetric with the `:`
symbol on the inside). However, at that point, the operator is getting
ugly and hard to type. Another option would be to use `:` for
ancestors and `::` for parents, but that is counterintuitive and get
annoying if you want to repeat it. So it seems that the best option is
to simply pick different symbols for parents/children and
ancestors/descendants/range.
This patch changes the ancestors/descendants operators to both be
`,,`. I'm not at all attached to that particular symbol. I suspect
we'll change it later.
Now that expressions may contain literal strings, we can simply have
functions accept only expressions arguments. That simplifies both the
grammar and the code.
A small drawback is that `description((foo), bar)` is now allowed and
does a search for the string "foo" (not "(foo)"). That seems
unlikely to trip up users.
Git refs with names containing e.g "-" are currently not accepted
symbol names, and I don't plan to change the grammar to accept
them. Instead, let's have the user quote symbol names containing
unusual characters. That way we can keep these symbols reserved for
revset operators.
With this patch the user can do e.g. `jj diff -r '"v2.9.0-rc2"'`.
This adds `children(<set>)` and `<set>:` for the children of the given
set, and `descendants(<set>)` and `<set>:*` for the descendants of the
given set. The children and descendants are filtered to be among
ancestors of non-obsolete commits. I haven't added a way of overriding
that yet.
This is especially important now that we leak the rule names into the
`SyntaxError` message. For example, the error message when doing `jj
diff -r :` will now mention "expected parents_op, ancestors_op, or
primary". It seems much clearer with the "_op" suffixes there. Longer
term, we should think more about how we can best surface syntax errors
from the library crate.
This adds `parents(foo)` and `ancestors(foo)` as alternative ways of
writing `:foo` and `*:foo`.
I haven't added support for for whitespace yet; the parsing is very
strict. The error messages will also need to be improved later.
