*NB: This is the initial change to introduce the token of lookahead, but this
does not fully integrate it. In particular, this is missing from the
stitching/delegation layer.*
This has been a long time coming, I suppose, though I had tried to avoid it
with `Parser::delegate_lookahead`. But the problem with doing that is that
it forced the ParserState to recurse, which both violates that I want no
looping constructs except for the toplevel, and performs additional stack
allocation as it is not in tail position.
The final straw was having to both return an error _and_ an aggregate object
for the attribute parser when an unexpected element is encountered (this
code is not yet committed). One option was to add a recovery object to the
error object, and formalize that, but then we have other concerns; for
example, what if that recovery object triggered an error? We'd have to mask
either the old or the new error. But we wouldn't want to mask either,
because the object causing the error would be the aggregate attributes,
which is _not_ a recovery object, but actual data we want to emit. And so
it's a kluge right off of the bat.
The use of a token of lookahaed is a more traditional approach and has uses
outside of just this one scenario. It'll also allow for the removal of
recursion from the existing ParserStates, and possibly the elimination of
dead state associated data, though I may end up leaving that; more to come.
Rust will also optimize away lookahead storage and processing in Parsers
that do not utilize it.
DEV-7145
I'd feel rather silly if I used `debug_assert!` for the sake of tests and
they weren't actually being run due to optimization settings.
This is just to catch potential future regressions; all is well today.
DEV-7145
There was only one test outside of the `parse` module using these
fields. The next commit will be introducing lookahead, and I do not want to
have to trust callers to ensure invariants are met.
DEV-7145
This reverts commit b973d36862.
Alright, I'm getting sick of fighting with myself on this. But rather than
just removing the last commit, I'm going to keep it around, so that my
thoughts are clearly documented for my future quarrels with myself.
Firstly: this added more overhead than I wanted it to. While it wasn't
significant, it did add 100--150ms to one of our largest systems, up from
~2.8s, which seems a bit much for a token that's really just meant to make
life easier for the parser.
Further, it seems that all I've managed to do is push my original problem to
a different layer---this started as a means to resolve having to emit both
an object and an error simultaneously in the case where aggregate attribute
parsing has completed, but we encounter an error on the next token (e.g. an
unexpected element). But XIRF, if it's missing AttrEnd, should throw an
error, but should also recover. Recovery is easy---just assume that it was
present---_but then we don't emit a XIRF `AttrEnd` token_, which is
necessary for downstream systems. So we'd need to either:
(a) emit both a token and an error; or
(b) panic.
But if we're doing (a), then the need for `AttrEnd` goes away, because it
solves the original problem (though the other concerns of the previous
commit still stand). (b) is not ideal at all, even though the missing token
does represent an internal system error; it's not something the user can
correct. But, given that it's something that the user cannot correct,
doesn't that imply that it's an awkward thing to include in the token
stream? So back to `AttrEnd` being an awkward PITA to have.
So, given (a), I'll just do that: errors will become more of a "hey, this
error just occurred, but I'm trying to recover---here's an object that you
should use if you choose to continue parsing, but it may or may not be what
you're looking for; proceed with caution". That flips the original script:
I imagined having external systems feed recovery tokens, but this
encapsulates recovery within the parser, which really is more appropriate,
though less flexible than having an omniscient external recovery system;
such a monolith was always an awkward concept and would be difficult to
implement cleanly.
This can also potentially be implemented as a generalization of the Dead
state change that allowed an object to be emitted alongside the
lookahead/error.
Anyway, back to where I was...I'm sure I'll look back on this in the future
shaking my head, reflecting on how naive I was.
DEV-7145
AttrEnd was initially removed in
0cc0bc9d5a (and the commit prior), because
there was not a compelling reason to use it over a lookahead
operation (returning a token via the a dead state transition); `AttrEnd`
simply introduced inconsistencies between the XIR reader (which produced
AttrEnd) and internal XIR stream generators (e.g. the lowering operations
into XIR->XML, which do not).
But now that parsers are performing aggregation---in particular the
attribute parser-generator `xir::parse::attr`---this has become quite a
pain, because the dead state is an actionable token. For example:
1. Open
2. Attr
3. Attr
4. Open
5. ...
In the happy case, token #4 results in `Parsed::Incomplete`, and so can just
be transformed into the object representing the aggregated attributes. But
even in this happy path, it's ugly, and it requires non-tail recursion on
the parser which requires a duplicate stack allocation for the
`ParserState`. That violates a core principle of the system.
But if there is an error at #4---e.g. an unexpected element---then we no
longer have a `Parsed::Incomplete` to hijack for our own uses, and we'd have
to introduce the ability to return both an error and a token, or we'd have
to introduce the ability to keep a token of lookahead instead of reading
from the underlying token stream, but that's complicated with push parsers,
which are used for parser composition. Yikes.
And furthermore, the aggregation has caused me to introduce the ability to
override the dead state type to introduce both a token of lookahead and
aggregation information. This complicates the system and is going to be
confusing to others.
Given all of this, AttrEnd does now seem appropriate to reintroduce, since
it will allow processing of aggregate operations when encountering that
token without having to worry about the above scenario; without having to
duplicate a `ParseState` stack; without having to hijack dead state
transitions for producing our aggregate object; and everything else
mentioned above.
This commit does not modify those abstractions to use AttrEnd yet; it
re-introduces the token to the core system, not the parser-generators, and
it doesn't yet replace lookahead operations in the parsers that use
them. That'll come next. Unlike the commit that removed it, though, we are
now generating proper spans, so make note of that here. This also does not
introduce the concept to XIRF yet, which did not exist at the time that it
was removed, so XIRF is filtering it out until a following commit.
DEV-7145
This is not longer needed after the previous commit, with static spans
having been replaced by `const` spans.
This used to be required before Rust acquired better const features, and
before I had preinterned symbols.
DEV-7145
This isn't conceptally all that significant of a change, but there was a lot
of modify to get it working. I would generally separate this into a commit
for the implementation and another commit for the integration, but I decided
to keep things together.
This serves a role similar to AttrSpan---this allows deriving a span
representing the element name from a span representing the entire XIR
token. This will provide more useful context for errors---including the tag
delimiter(s) means that we care about the fact that an element is in that
position (as opposed to some other type of node) within the context of an
error. However, if we are expecting an element but take issue with the
element name itself, we want to place emphasis on that instead.
This also starts to consider the issue of span contexts---a blob of detached
data that is `Span` is useful for error context, but it's not useful for
manipulation or deriving additional information. For that, we need to
encode additional context, and this is an attempt at that.
I am interested in the concept of providing Spans that are guaranteed to
actually make sense---that are instantiated and manipulated with APIs that
ensure consistency. But such a thing buys us very little, practically
speaking, over what I have now for TAMER, and so I don't expect to actually
implement that for this project; I'll leave that for a personal
project. TAMER's already take a lot of my personal interests and it can
cause me a lot of grief sometimes (with regards to letting my aspirations
cause me more work).
DEV-7145
Non-attribute and non-empty start/end tags will have their whitespace
as part of the produced span. This sets us up for a following change that
will allow for deriving the name span from this span given a QName, which
gives us a span that both represents the entire XIR token and allows
deriving the element name.
An accurate token span is necessary for parsing errors where an element was
not expected, while an element name span is more appropriate for issues of
grammar and semantic errors that deal not with the fact that an element was
encountered, but _what_ element was encountered.
DEV-7145
This both adds clarifying tests and corrects the case of `<foo/>`, where the
offset was erroneously off by one---it saw that there were no attributes and
added a byte thinking it'd include `>`, as in `<foo>`.
DEV-7145
This is the first parser generator for the parsing framework. I've been
waiting quite a while to do this because I wanted to be sure that I
understood how I intended to write the attribute parsers manually. Now that
I'm about to start parsing source XML files, it is necessary to have a
parser generator.
Typically one thinks of a parser generator as a separate program that
generates code for some language, but that is not always the case---that
represents a lack of expressiveness in the language itself (e.g. C). Here,
I simply use Rust's macro system, which should be a concept familiar to
someone coming from a language like Lisp.
This also resolves where I stand on parser combinators with respect to this
abstraction: they both accomplish the exact same thing (composition of
smaller parsers), but this abstraction doesn't do so in the typical
functional way. But the end result is the same.
The parser generated by this abstraction will be optimized an inlined in the
same manner as the hand-written parsers. Since they'll be tightly coupled
with an element parser (which too will have a parser generator), I expect
that most attribute parsers will simply be inlined; they exist as separate
parsers conceptually, for the same reason that you'd use parser combinators.
It's worth mentioning that this awkward reliance on dead state for a
lookahead token to determine when aggregation is complete rubs me the wrong
way, but resolving it would involve reintroducing the XIR AttrEnd that I had
previously removed. I'll keep fighting with myself on this, but I want to
get a bit further before I determine if it's worth the tradeoff of
reintroducing (more complex IR but simplified parsing).
DEV-7145
This was missed. It was not possible, using the documentation
alone (without looking at the linked source) to tell what the QName actually
represented, though you could assume by the name.
DEV-7145
This is partly an experiment, but is designed to simplify producing English
sentences in various contexts. It makes use of a not only unstable, but
incomplete, Rust feature---adt_const_params, for a static str const type
parameter. Hopefully that ends up being stabalized.
This uses types, but it's the same as function composition due to Rust's
monomorphization.
DEV-7145
`ParseState` originally required `Default` for use with `mem::take` in
`Parser::feed_tok`. This unfortunately cannot last, since more specialized
parsers require context during initialization in order to provide useful
diagnostic information. (The other option is to require the caller to
augment errors with diagnostic information, but that would have to be
duplicated by every caller and complicates parser composition; I'd prefer
those diagnostic details remain encapsulated.)
Replacing `Default` with `Option` is uglier, but it ends up producing the
same assembly as `mem::take` did, at least at the time of writing. Because
Rust is able to elide unnecessary moves using this implementation, there is
no need for `unwrap_unchecked` or other unsafe methods, which is great,
since it shows that this parsing methodology is viable entirely in safe
Rust.
DEV-7145
Previously, `ParseStatus::Dead` always yielded
`ParseState::Token`. However, I'm working on introducing parsers that
aggregate (parsing XML attributes into structs), and those parsers do not
know that they have completed aggregation until they reach a dead state;
given that, I need to yield additional information at that time.
I played around with a number of alternative ideas, but this ended up being
the cleanest, relative to the effort involved. For example, introducing
another parameter to `ParseStatus::Dead` was too burdensome on APIs that
ought not concern themselves with the possibility of receiving an object in
addition to a lookahead token, since many parsers are not capable of doing
so (given that they map M:(N<=M)).
Another option that I abandoned fairly quickly was having
`is_accepting` (potentially renamed) return an aggregate object, since
that's on the side and didn't feel like it was part of the parsing pipeline.
The intent is to abstract this some in a new `ParseState` method for
delegation + aggregation.
DEV-7145
I'll document it more formally eventually, but this settles on a mix of the
two: square brackets and dashes for intervals, `+` for intersecting lines,
byte offsets below interval endpoints, and names below that.
The docblock for `Span` itself iss still off; I'll probably just take one of
the test cases and paste it there at some point.
DEV-7145
This replaces a tuple with a tuple struct that allows for calculating more
complete span information, such as the span encompassing the entire
attribute and the value span including the surrounding quotes.
This includes logic that ought to be abstracted into `Span` itself, and it's
not as formal as I'd like it to be (e.g. not ensuring context), but this is
a good starting point.
Note that parsers call `Token::span`, which in turn calculates the attribute
span, each time an attribute is encountered during lowering. But Rust does
a good job at optimizing away unnecessary operations, so this didn't have an
observable impact on time.
DEV-7145
This provides much more clarity as to what is going on. Further, it's less
ambiguous, since I'm about to introduce a new type of xmlo lowering into XIR
for writing the actual xmlo files.
DEV-7145
This allows `XmlXirReader` to be used in a `Lower` operation, just as
everything else, bringing me one step closer to a pipeline that can be
concisely represented; this is finally beginning to unify in a clear way,
though it is still a bit of a mess.
This causes `XmlXirReader` to _act_ like a `parse::Parser` in that it yields
a `ParsedResult`, but it does not use `parse::Parser` itself; that was the
_original_ plan: convert it into a `ParseState` where `XmlXirReader` became
a context, and force `Parser` to yield by feeding it a stream of tokens with
`repeat`, but that ended up performing poorly relative to this change. I
did some investigation, which I might write about in the future, but for
now, this solution works just fine.
DEV-7145
This abstraction has grown quite a bit, and it's time to start formalizing
it a bit. This split doesn't change any behavior, but it does start to make
it easier to reason about by clearly stating the broad components and how
they interact with one-another.
This doesn't yet move the tests; those will come next, but they are very
few. The reason I gave previously for this was because (a) they're tested
indirectly via the systems that utilize them and (b) because the abstraction
was not yet settled on the process was already very expensive. No test
coverage was lost---it's only that failures were potentially harder to debug
on test failures, but in practice not even this was true, because the deeply
expressive types all but ensured that, if it compiles, it will function in a
way that is expected. Unit tests and documentation for this system will be
added once I'm sure that this abstraction is in a proper state.
DEV-7145
This also modifies `poc` such that `Lower` is invoked as an associated
function rather than a method to emphasize the pattern that is forming, so
that it can be later abstracted away.
DEV-11864
The `while_ok` can just be implied with a lowering operation, and that
reduces the name complexity so that we can maybe introduce even more
specialized methods without resulting in a huge sentence as a name.
DEV-11864
This finally uses `parse` all the way up to aggregation into the ASG, as can
be seen by the mess in `poc`. This will be further simplified---I just need
to get this committed so that I can mentally get it off my plate. I've been
separating this commit into smaller commits, but there's a point where it's
just not worth the effort anymore. I don't like making large changes such
as this one.
There is still work to do here. First, it's worth re-mentioning that
`poc` means "proof-of-concept", and represents things that still need a
proper home/abstraction.
Secondly, `poc` is retrieving the context of two parsers---`LowerContext`
and `Asg`. The latter is desirable, since it's the final aggregation point,
but the former needs to be eliminated; in particular, packages need to be
worked into the ASG so that `found` can be removed.
Recursively loading `xmlo` files still happens in `poc`, but the compiler
will need this as well. Once packages are on the ASG, along with their
state, that responsibility can be generalized as well.
That will then simplify lowering even further, to the point where hopefully
everything has the same shape (once final aggregation has an abstraction),
after which we can then create a final abstraction to concisely stitch
everything together. Right now, Rust isn't able to infer `S` for
`Lower<S, LS>`, which is unfortunate, but we'll be able to help it along
with a more explicit abstraction.
DEV-11864
This is intended to describe, to the user, the state that the parser is
in. This will be used to convey additional information for general parser
errors, but it should also probably be integrated into parsers' individual
errors as well when appropriate.
This is something I expected to add at some point, but I wanted to add them
because, when dealing with lowering errors, it can be difficult to tell
what parser the error originated from.
DEV-11864
The `*_iter_while_ok` functions now compose like monads, flattening `Result`
at each step and drastically simplifying handling of error types. This also
removes the bunch of `?`s at the end of the expression, and allows me to use
`?` within the callback itself.
I had originally not used `Result` as the return type of the callback
because I was not entirely sure how I was going to use them, but it's now
clear that I _always_ use `Result` as the return type, and so there's no use
in trying to be too accommodating; it can always change in the future.
This is desirable not just for cleanup, but because trying to refactor
`asg_builder` into a pair of `Parser`s is really messy to chain without
flattening, especially given some state that has to leak temporarily to the
caller. More on that in a future commit.
DEV-11864
This was always the intent, but I didn't have a higher-level object
yet. This removes all the awkwardness that existed with working the root
in as an identifier.
DEV-11864
This wraps `Ident` in a new `Object` variant and modifies `Asg` so that its
nodes are of type `Object`.
This unfortunately requires runtime type checking. Whether or not that's
worth alleviating in the future depends on a lot of different things, since
it'll require my own graph implementation, and I have to focus on other
things right now. Maybe it'll be worth it in the future.
Note that this also gets rid of some doc examples that simply aren't worth
maintaining as the API evolves.
DEV-11864
A previous commit mentioned that there's not a place for `Dim`, and
duplicated it between `asg` and `xmlo`. Well, `Dtype` is also needed in
both, and so here's a home for now.
`Dtype` has always been an inappropriate detail for the system and will one
day be removed entirely in favor of higher-level types; the machine
representation is up to the compiler to decide.
DEV-11864
asg_builder is about to be replaced, but in the process of simplifying the
destination IR (the ASG), I'm moving things into the proper place. This
never belonged here---it belongs with the actual lowering operation.
Previously, this was not reasoned about in terms of a lowering operation,
and was written when I was first introducing myself to Rust and trying to
get a proof-of-concept linker working.
DEV-11864
This matches xmlo::Dim, and could be the same thing, if we can find a home
for it in the future; it's not worth creating such a home right now when I'm
not yet sure what else ought to live there; the duplication may be fine.
The conversion from xmlo needs to be moved, and `Dim` is going to be used
for more than just identifiers (expressions will have type inference
performed).
DEV-11864
This allows retrieving and providing a context to a `Parser`. This is
intended for use with an aggregating parser, in particular to construct the
ASG and return it.
This is a component of a change that replaces `asg_builder` with a
`Parser`-based lowering into the ASG, but there are still changes that need
to be made to simplify things and complete its integration.
DEV-11864
Previously, since the graph contained only identifiers, discovered roots
were stored in a separate vector and exposed to the caller. This not only
leaked details, but added complexity; this was left over from the
refactoring of the proof-of-concept linker some time ago.
This moves the root management into the ASG itself, mostly, with one item
being left over for now in the asg_builder (eligibility classifications).
There are two roots that were added automatically:
- __yield
- __worksheet
The former has been removed and is now expected to be explicitly mapped in
the return map, which is now enforced with an extern in `core/base`. This
is still special, in the sense that it is explicitly referenced by the
generated code, but there's nothing inherently special about it and I'll
continue to generalize it into oblivion in the future, such that the final
yield is just a convention.
`__worksheet` is the only symbol of type `IdentKind::Worksheet`, and so that
was generalized just as the meta and map entries were.
The goal in the future will be to have this more under the control of the
source language, and to consolodate individual roots under packages, so that
the _actual_ roots are few.
As far as the actual ASG goes: this introduces a single root node that is
used as the sole reference for reachability analysis and topological
sorting. The edges of that root node replace the vector that was removed.
DEV-11864
In the actual implementation (outside of tests), this is always looking up
before adding the symbol. This will simplify the API, while still retaining
errors, since the identifier will fail the state transition if the
identifier did not exist before attempting to set a fragment. So while this
is slower in microbenchmarks, this has no effect on real-world performance.
Further, I'm refactoring toward a streaming ASG aggregation, which is a lot
easier if we do not need to perform lookups in a separate step from the
ASG's primitives.
DEV-11864
`PartialEq` remains, and is all that is needed. See previous commit
regarding the removal of this same bound from `Context`.
This can be re-added if it ends up actually being necessary. But Tokens are
ephemeral and used only in lowering pipelines, using pattern matching.
DEV-11864
These traits are no longer necessary now that I'm using concrete types; they
just add unnecessary noise and confusion as I attempt to further refactor.
Don't abstract prematurely.
DEV-11864
This removes the generic on the Asg (which was formerly BaseAsg),
hard-coding `IdentObject`, which will further evolve. This makes the IR an
actual concrete IR rather than an abstract data structure.
These tests bring me back a bit, since they were written as I was still
becoming familiar with Rust.
DEV-11864
This is the beginning of an incremental refactoring to remove generics, to
simplify the ASG. When I initially wrote the linker, I wasn't sure what
direction I was going in, but I was also negatively influenced by more
traditional approaches to both design and unit testing.
If we're going to call the ASG an IR, then it needs to be one---if the core
of the IR is generic, then it's more like an abstract data structure than
anything. We can abstract around the IR to slice it up into components that
are a little easier to reason about and understand how responsibilities are
segregated.
DEV-11864
This is unnecessarily restrictive, since we do not require anything further
than `PartialEq` for the situations where we care about equality (tests).
DEV-11864
This is too restrictive, especially for parsers that fold into something,
like the ASG, which may exist prior to invoking the parser.
This moves the trait bound to the functions that actually need it. Those
obviously cannot be used if the Context does not implement `Default`, but
I'll provide alternative conveniences.
DEV-11864
RSG (Ryan Specialty Group) recently announced a rename to Ryan Specialty (no
"Group"), but I'm not sure if the legal name has been changed yet or not, so
I'll wait on that.
These are no longer TODOs---they represent invalid tokens.
I'm going to put effort into providing further context with the diagnostic
system [right now] because these are internal errors caused by either
miscompilation or an incomplete reader.
DEV-10936
This was missed when removing it from other Display impls when the new
diagnostic system was introduced. Raw `Span`s display byte offsets and the
context, which is no longer desirable as part of an error message.
DEV-10936
I had waited to provide more documentation until I was sure that the
abstraction was not going to change significantly; there was a lot of
refactoring in prior commits.
DEV-12151
This moves construction out of `From` and into separate associated
functions, which can be further simplified in a bit.
We also need unit tests for this, since this still relies on integration
tests due to the cost of the aggressive and tight refactoring iterations.
DEV-12151
Previously, when adjacent duplicate spans were both resolved, if one failed,
the other certainly would, which would result in duplicate labels each
squash. Elided spans do not have syslabels, and so this is no longer a
concern.
DEV-12151
This was removed in a previous commit while working on simplifying the
implementation, with the hope of returning to it once things were in a
better place. They are, so let's bring it back.
DEV-12151
`SpanLabel` was created during a very early refactoring of this system, and
I've just been fighting with it sense. This removes it, and simplifies
some things in the process.
It also makes clear that `Level` is never optional and removes the awkward
`Level::default` that was there previously; the default is now the lowest
level, which will always be able to be escalated.
DEV-12151
This does what the original proof-of-concept implementation did---skip a
span that was just processed, since it'll be squashed into the previous
anyway. These duplicate spans originate from the diagnostic system when
producing supplemental help information.
DEV-12151
Tests are large and will be getting larger. The source will also grow as
it's better documented and cleaned up. It's getting more difficult to
navigate efficiently and concurrently modify implementation and tests, and
parsing via LSP is getting slower with certain types of changes.
DEV-12151
Alright, starting to settle on an abstraction now, and things are coming
together. This gives us line numbers in the previously-empty gutter, and
widens the gutter to accommodate. Gutters are normalized across
sections. Sections are not yet collapsed for sequential line numbers in the
same context.
Exciting!
Here's an example, on an xmlo file:
error: expected closing tag for `preproc:symtable`
--> /home/.../foo.xmlo:16:4
|
16 | <preproc:symtable xmlns:map="http://www.w3.org/2005/xpath-functions/map">
| ----------------- note: element `preproc:symtable` is opened here
--> /home/.../foo.xmlo:11326:4
|
11326 | </preproc:wrong>
| ^^^^^^^^^^^^^^^^ error: expected `</preproc:symtable>`
DEV-12151
The `Section` itself is now responsible for outputting the gutter, which
puts us in a position to be able to apply consistent formatting without
having to propagate width data to every line variant.
Now `SourceLine` _does_ actually correspond to a line of output, which will
allow for better formatting (e.g. collapsing padding) and, importantly,
proper management of gutters.
Note that the seemingly unnecessary `SectionSourceLine` allows for a subtle
consistent formatting for all variants' gutters in `SectionLine`, which will
allow us to hoist that rendering out in the next commit. The other option
was to include a trailing space for padding and marks, but that is not only
sloppy and undesirable, but asking for confusion, especially in editors (like
mine) that trim trailing whitespace.
DEV-12151
If a column isn't present, it degrades to displaying labels like footnotes
anyway, so this simplifies the system rather than catering to a rare
case. With that said, this does lose functionality, since it does not
render the source line at all, even though we _could_ do so.
I may re-introduce that rendering after some further refactoring,
specifically for gutters.
DEV-12151
Using a byte vector just makes life more difficult with regard to preparing
the diagnostic reports. We're already validating UTF-8 data for column
generation, which is necessary for a robust report, so let's just store it
as a String to begin with.
DEV-12151
Note that, if a span is first encountered with a mark but with _no_ label,
the first label (if collapsed) will be on the next line. This allows a span
to be marked without extra visual noise if it's not necessary, and to be
able to trust that it'll stay that way.
Until coloring is introduced, this may or may not be easier to read
depending on context.
This is also not yet taking into account where on the line it begins, and so
may render poorly if the span is at the end of a line. That will be fixed
later on.
DEV-12151
This is now visible in the diagnostic output. Example at this point in
time, on an xmlo file for one of our smallest systems:
error: expected closing tag for `preproc:symtable`
--> /home/.../foo.xmlo:16:4
|
| <preproc:symtable xmlns:map="http://www.w3.org/2005/xpath-functions/map">
| -----------------
= note: element `preproc:symtable` is opened here
--> /home/.../foo.xmlo:11326:4
|
| </preproc:wrong>
| ^^^^^^^^^^^^^^^^
= error: expected `</preproc:symtable>`
DEV-12151
Looking more and more Rust-like. Shameless copy.
TBH I forget what character it uses for help, but it's easy enough to
change.
Also, to be clear: this is modeled after Rust, but it's not a requirement of
mine that it look exactly like it. I just like the general style; I'll
surely deviate over time, as appropriate (or as I feel like it).
DEV-12151
This has the effect of highlighting the columns of the source lines using
'^' as an underline.
The next step will be to have the underline character depend on the
`Level`.
If this commit message doesn't sound all that exciting, given what it
finally achieved after all this time, it's because I'm exhausted, and my
prototype has already taken my excitement. But this is significant, given
all the work leading up to it.
There is some code cleanup needed and some unit tests that ought to be
written rather than relying on integration, but considering how much this is
being refactored, I don't want to add to that refactoring cost just yet
before gutters are introduced and I know things are settled for now.
DEV-12151
This has been a lot of refactoring for something that I prototyped a week
ago, and the prototype is still further along in its output formatting (it
has line numbering in gutters and span markings).
But, this has come a long way, and I'm happy with it overall, though I'm not
happy with my slow pace and struggle to maintain focus. But those are
personal issues.
This leaves a lot to be desired, but at the same time is still really
helpful. There's a couple notable TODOs regarding pointless allocation and
UTF8 re-checking, but otherwise, the feature-related steps are:
- Gutters with line numbers; and
- Marking columns associated with the span.
DEV-12151
Rather than squashing as a separate operation, and explicitly denoting when
it occurred, we'll just always squash, as was done before these changes. It
doesn't really make sense to make this optional and there's not any value in
keeping the decision around.
This also sets us up favorably for future changes: it creates a vector of
labels, which can be analyzed later to determine how to best lay out marks
and labels.
DEV-12151
Just renames the lifetime to refer to the `Diagnostic`, rather than a
`Label` returned by it, which was all `'l` was previously used for.
Note that many labels have a `'static` lifetime; this doesn't change that or
somehow cause it to reallocate; the label must life _for at least `'d`_.
DEV-12151
Rather than rendering the diagnostic `Display` message to a string only to
copy it to yet another buffer later on, this simply stores a reference to
the `Diagnostic` that was provided. This also adds a type to the `Report`
associating it with the provided `Diagnostic`, which does seem appropriate,
given that the report was produced for it.
I should probably rename '{l=>d} now.
DEV-12151
Rather than writing to the provided `Write` object, this produces a `Report`
object. While a lifetime still exists for the diagnostic data (labels,
specifically), I was able to remove the other lifetime resulting from
`ResolvedSpan` by transferring ownership of the data to the `Report`
itself. Once actual source lines are integrated shortly, `Report` will
include those as well.
This has been a tedious process, but it's coming together. Hopefully these
commits documenting the progressive and ugly refactoring are found useful by
some reader in the future.
DEV-12151
The line number was getting special treatment that is simply not worth the
cost (with regards to how burdensome it is on the type definitions). This
simplifies things quite a bit.
If we want header customization in the future, we can worry about that in a
different way, or allow the header as a whole to be swapped out, rather than
its constituents.
DEV-12151
`HeadingColNum` is no longer constructed by `HeadingLineNum`. This both
narrows the types and required data (e.g. removing dummy values in test
cases), and reduces the coupling (by favoring composition, but still coupled
with the concrete type).
DEV-12151
I'm unhappy with the current state of this, which is why I haven't settled
on docs or unit tests for these changes yet (though note that the
integration tests do cover these changes)---this is still a prototype
refactoring.
In particular, this needs to do more lowering---the `ResolvedSpan` and
`MaybeResolvedSpan` need to be eliminated and lowered into exactly what is
needed so that we can stop reasoning about them and propagating them.
Further, having lines and columns lazily evaluate themselves for
display---based on `MaybeResolvedSpan`---adds extra generics that shouldn't
be necessary; they should be pre-computed and store the concrete data they
need in variants. Display shouldn't involve computation beyond formatting
of pre-computed data.
That was always the plan, but this refactoring has been incremental.
Anyway: this is in a working and integration-tested state, but it's going to
change.
DEV-12151
This generalizes the types a bit more and introduces unit tests. Note that
these are still also covered by integration tests.
The next step will be to finish generalizing
`<VisualReporter as Reporter>::render`, after which I'll get back to the
task of outputting the source line along with markings and labels.
DEV-12151
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
Mike Gerwitz