This is just to provide clarity. `ctx` is not so widely used that we
benefit from such a short identifier, and it's not worth the cognitive
burden of people unfamiliar with what it may mean.
DEV-12151
This is redundant with the `Endpoints` variant, although it did read
better. It's just another case to have to handle.
I was originally going to use `std::ops::RangeInclusive` for `Endpoints`,
however that struct also contains an extra bool indicating whether it was
exhausted (as an iterator), which isn't appropriate for this.
DEV-12151
This logic is still covered by the integration tests; I'll be adding unit
tests once it's decoupled to the point where that's possible, which should
be shortly, and after I make sure this is the route I do want to go down.
DEV-12151
This simplifies types and error handling since we will always have at least
one line, provided that the span is within the range of the context. To
ensure that, this patch introduces a new error.
DEV-12151
I did not initially introduce lifetimes because I wasn't sure how the system
was going to evolve, but now lifetimes are going to be needed in a number of
contexts. The core of TAMER is able to avoid lifetimes in most instances
because of its internment system, but its use is not appropriate for the
diagnostic system's buffers (beyond sourcing strings from already-interned
data).
DEV-12151
Determining the column number is not as simple as performing byte
arithmetic, because certain characters have different widths. Even if we
only accepted ASCII, control characters aren't visible to the user.
This uses the unicode-width crate as an alternative to POSIX wcwidth, to
determine (hopefully) the number of fixed-width cells that a unicode
character will take up on a terminal. For example, control characters are
zero-width, while an emoji is likely double-width. See test cases for more
information on that.
There is also the unicode-segmentation crate, which can handle extended
grapheme clusters and such, but (a) we'll be outputting the line to the
terminal and (b) there's no guarantee that the user's editor displays
grapheme clusters as a single column. LSP measures in UTF-16,
apparently. I use both Emacs and Vim from a terminal, so unicode-width
applies to me. There's too much variation to try to solve that right now.
The columns can be considered a visual span---this gives us enough
information to draw line annotations, which will happen soon.
Here are some useful links:
- https://hsivonen.fi/string-length/
- https://unicode.org/reports/tr29/
- https://github.com/rust-analyzer/rowan/issues/17
- https://www.reddit.com/r/rust/comments/gpw2ra/how_is_the_rust_compiler_able_to_tell_the_visible/
DEV-10935
This does not yet resolve columns, and omits the length of the span, but
it's starting to come together.
This is particularly exciting for me to see because I've been wanting line
numbers in TAME error messages for over a decade.
DEV-10935
This does adds support for rewinding the underlying buffer when necessary to
read a span that occurs earlier within the same context (which could also
include the same span read twice).
As part of this change, I cleaned up the code a bit. Working with this
system can be confusing with the different meanings of the byte offsets and
the different ways of interpreting lines relative to the span that is
provided. There's not a lot of code here, but it represents a lot of work
to get right.
This works, but it's ugly and requires some cleanup. It shows that there
are some interesting considerations when determining how to best represent
the location of spans to the user in a way that is intuitive.
This is not yet integrated with the reporter, which will require a layer to
load a `Context` from disk.
DEV-10935
This is a working concept that will continue to evolve. I wanted to start
with some basic output before getting too carried away, since there's a lot
of potential here.
This is heavily influenced by Rust's helpful diagnostic messages, but will
take some time to realize a lot of the things that Rust does. The next step
will be to resolve line and column numbers, and then possibly include
snippets and underline spans, placing the labels alongside them. I need to
balance this work with everything else I have going on.
This is a large commit, but it converts the existing Error Display impls
into Diagnostic. This separation is a bit verbose, so I'll see how this
ends up evolving.
Diagnostics are tied to Error at the moment, but I imagine in the future
that any object would be able to describe itself, error or not, which would
be useful in the future both for the Summary Page and for query
functionality, to help developers understand the systems they are writing
using TAME.
Output is integrated into tameld only in this commit; I'll add tamec
next. Examples of what this outputs are available in the test cases in this
commit.
DEV-10935
Mike Gerwitz