IntoTemplate will be cleaned up later. Perhaps, the lifetime parameter can be
removed at this point, but I'm planning to remove the IntoTemplate trait at all.
Now a compiled template doesn't have a static Context type internally. A
property is basically of "Fn() -> Result<O, _>" type, and a type-erased "self"
variable will be injected as needed.
Template<C> types will be refactored separately.
In short, this enables compilation of template of e.g. Vec<Commit> type by
using CommitTemplateLanguage.
A Template<C> was originally compiled for a specific type C, and invoked as
"Fn(&C) -> _". It was simple and intuitive, but we had to define the context
type C statically. Things got even worse by extensions support because we had
to provide object-safe hook point for each context type C.
This patch basically removes the Context type from compiled templates. The
"self" variable is injected through RefCell<Option<C>> placeholder. A compiled
template knows its "self" type, but the type can be decided per instance, not
per TemplateLanguage type. A drawback is that the "self" variable will have to
be cloned one more time.
The Template<C> abstraction no longer makes sense, and will be split to inner
Template<()> implementations (which usually represent printable types) and the
outer Template<C>.
Because GenericTemplateLanguage doesn't support any global resources, it no
longer makes sense to pass the language instance around to 0-ary keyword
functions.
These .wrap_<type>() functions aren't supposed to capture resources from the
language instance. It was convenient that wrap_() could be called without fully
spelling the language type, but doing that would introduce lifetime issue in
later patches.
I added type alias L to several places because the language type is usually
called L in generic code.
The original plan was to extend the globals table to implement "revset(expr)".
I'm not sure if that's more discoverable than "self.contained_in(revset_expr)"
method, but we can decide that later. Anyways, this patch adds typo suggestion
for global functions.
Prepares for migrating to table-based lookup. It's unlikely that the
implementor handles global function calls differently, but the core doesn't
have an access to the customized symbol table.
This serves the role of the formatter in Mercurial, but the provided features
are rather restricted compared to mercurial.formatter. That's because both
implementation language "Rust" and jj's template language are statically typed.
The current implementation works well for simple commands like "config list -T",
but it might be not okay for "branch list -T". If we implement branch templating
by using the generic mechanism, the commit summary part would have to be
evaluated as a separate template:
-T 'branch_name ++ target_commit_summary' (target_commit_summary: Template)
instead of
-T 'branch_name ++ commit_summary(target_commit)' (target_commit: Commit)
where the branch template language is a superset of the commit template
language.
