Commit Graph

7 Commits (e5c8a218c3c393c40bb36f2a8a9d0eba7bfa5556)

Author SHA1 Message Date
Mike Gerwitz 1ad2fb1dc8 Copyright year update 2022
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.
2022-05-03 14:14:29 -04:00
Mike Gerwitz cfc7f45bc4 tamer: Remove wip-xmlo-xir-reader
This entirely removes the old XmloReader that has since been replaced with a
XIR-based reader.

I had been holding off on this because the new reader is slower, pending
performance optimizations (which I'll do a little later on), however the
performance loss is of no practical consideration and only affects the
linker, which is still fast.

Therefore, it's better to get this old code out of the way to simplify
refactoring going forward.  In particular, I'm working on the diagnostic
system.

This is a little sad, in a way---this is some of my first Rust code that I'm
deleting.

DEV-10935
2022-04-11 16:11:49 -04:00
Mike Gerwitz ab181670b5 tamer: xir::reader: Initial introduction of spans
This is a large change, and was a bit of a tedious one, given the
comprehensive tests.

This introduces proper offsets and lengths for spans, with the exception of
some quick-xml errors that still need proper mapping.  Further, this still
uses `UNKNOWN_CONTEXT`, which will be resolved shortly.

This also introduces `SpanlessError`, which `Error` explicitly _does not_
implement `From<SpanlessError>` for---this forces the caller to provide a
span before the error is compatable with the return value, ensuring that
spans will actually be available rather than forgotten for errors.  This is
important, given that errors are generally less tested than the happy path,
and errors are when users need us the most (so, need span information).

Further, I had to use pointer arithmetic in order to calculate many of the
spans, because quick-xml does not provide enough information.  There's no
safety considerations here, and the comprehensive unit test will ensure
correct behavior if the implementation changes in the future.

I would like to introduce typed spans at some point---I made some
opinionated choices when it comes to what the spans ought to
represent.  Specifically, whether to include the `<` or `>` with the open
span (depends), whether to include quotes with attribute values (no),
and some other details highlighted in the test cases.  If we provide typed
spans, then we could, knowing the type of span, calculate other spans on
request, e.g. to include or omit quotes for attributes.  Different such
spans may be useful in different situations when presenting information to
the user.

This also highlights gaps in the tokens emitted by XIR, such as whitespace
between attributes, the `=` between name and value, and so on.  These are
important when it comes to code formatting, so that we can reliably
reconstruct the XML tree, but it's not important right now.  I anticipate
future changes would allow the XIR reader to be configured (perhaps via
generics, like a strategy-type pattern) to optionally omit these tokens if
desired.

Anyway, more to come.

DEV-10934
2022-04-08 13:59:37 -04:00
Mike Gerwitz 74ddc77adb tamer: xir::escape::CachingEscaper: allow(dead_code) for feature-flagged code
For now, until this feature flag is removed, so that we do not see warnings
when the flag is off.
2022-03-10 10:03:07 -05:00
Mike Gerwitz 8723ca154d tamer: xir::escape::CachingEscaper: Use new sym::st::ST_COUNT
This adds a constant `ST_COUNT` representing the number of statically
allocated symbols, and uses that to estimate an initial capacity for the
`CachingEscaper`.

This is just a guess (and is certainly too low), but we can adjust later on
after profiling, if it ever comes up.
2021-11-15 21:46:57 -05:00
Mike Gerwitz d710437ee4 tamer: xir::escape::CachingEscaper: New Escaper
As promised, this will cache previously seen escaped/unescaped values by
creating a two-way mapping between them.

DEV-11081
2021-11-15 16:44:24 -05:00
Mike Gerwitz 27ba03b59b tamer: xir::escape: Remove XirString in favor of Escaper
This rewrites a good portion of the previous commit.

Rather than explicitly storing whether a given string has been escaped, we
can instead assume that all SymbolIds leaving or entering XIR are unescaped,
because there is no reason for any other part of the system to deal with
such details of XML documents.

Given that, we need only unescape on read and escape on write.  This is
customary, so why didn't I do that to begin with?

The previous commit outlines the reason, mainly being an optimization for
the echo writer that is upcoming.  However, this solution will end up being
better---it's not implemented yet, but we can have a caching layer, such
that the Escaper records a mapping between escaped and unescaped SymbolIds
to avoid work the next time around.  If we share the Escaper between _all_
readers and the writer, the result is that

  1. Duplicate strings between source files and object files (many of which
     are read by both the linker and compiler) avoid re-unescaping; and
  2. Writers can use this cache to avoid re-escaping when we've already seen
     the escaped variant of the string during read.

The alternative would be a global cache, like the internment system, but I
did not find that to be appropriate here, since this is far less
fundamental and is much easier to compose.

DEV-11081
2021-11-12 14:03:23 -05:00