Look ahead before testing for EOF.
This fixes panics in saphyr's test_multiline_trailing_newline and
test_multiline_leading_newline tests, in which `self.input.next_is_z`
would be called on an empty buffer and panic in `peek`
Previously, we often used the scanner state to infer the positions of
mappings. This is sometimes wrong, because the scanner has already
scanned ahead by the time the mapping is parsed.
This commit adds a check to the test suite, asserting that parser event
positions are all observed in order, and it fixes the scanner and parser
to make the new check pass.
Hiding character fetching behind this interface allows us to create more
specific implementations when is appropriate. For instance, an instance
of `Input` can be created for a `&str`, allowing for borrowing and more
efficient peeking and traversing than if we were to fetch characters one
at a time and placing them into a temporary buffer.
These are corner cases not tested by the `yaml-test-suite`.
Parsing for the reported input has been fixed, as well as other
similar-looking inputs which make use of nested implicit flow mappings
and implicit null keys and values.
Fixes#1.
These tests were sucecssfully converted to Rust files to include and are
no longer necessary in this repository.
Should they become relevant again in the future, they can always be
checked out from a previous commit.
This is a huge commit that cannot easily be broken down as it contains
fixes for the next ignored test in the suite which, one fixed, broke
tests that used to pass and were only then fixed.
There is also a substantial amount of comments that were added,
especially around `SimpleKey`. Minor improvements around the code were
added and I did not bother making a separate commit for them.
Overall, that commit fixes 7 tests from the matrix that were related to
the handling of simple keys.
