Add json_document and json_view, a read-only, zero-copy index of a
JSON text, as the first public slice of the zero-copy view (#5295).
A parse produces a flat array of 16-byte nodes in document order,
one per value and one per object key. Strings stay in the source
text; escaped strings are decoded into an arena. Integers are
converted while their digits are in the cache; floats keep only
their digit layout and are converted on read. Containers store the
size of their subtree, so a reader can step over one in constant
time. A document makes a handful of allocations, however many
values it has.
The parser accepts exactly what json::parse accepts, with every
combination of ignore_comments and ignore_trailing_commas, with and
without a trailing NUL, and under JSON_STRICT_NUL_HANDLING. It is
portable C++11 and does not depend on byte order.
basic_json_document adds parse, parse_copy, accept, read (reuses a
document's memory), root, is_discarded, source, owns_source,
node_count, memory_usage, and shrink_to_fit. basic_json_view adds
type, the is_* queries, operator bool, size, empty, materialize,
and source_offset. A parse error throws the same exception
basic_json::parse would throw for the same input, message and
position included.
detail::abi_config keeps JSON_STRICT_NUL_HANDLING and
JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON readable after json.hpp
undefines them, in the ABI namespace so they always match the
basic_json in use.
A NUL byte that ends a // comment is the end of the input, as in
parse() since #5696.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
This should have no effect for header only libraries as mentioned.
It was previously removed in e509007d but then accidentally added
again in 26cfec34.
Signed-off-by: Jeremy Nimmer <jeremy.nimmer@tri.global>
* Add missing headers to BUILD.bazel and make its generator reproduce it
The "json" cc_library did not list three headers that the library
includes:
- detail/meta/logic.hpp (added in #5016, included by from_json.hpp)
- detail/input/number_parse.hpp (added in #5283, included by lexer.hpp)
- detail/input/string_scan.hpp (added in #5283, included by lexer.hpp
and serializer.hpp)
Bazel's sandbox only exposes declared headers, so any target depending
on @nlohmann_json//:json and including <nlohmann/json.hpp> failed with
"'nlohmann/detail/meta/logic.hpp' file not found".
The file could not simply be regenerated, because the generator behind
"make BUILD.bazel" was stale: it wrote only the "json" cc_library and
dropped the load() statements, the license block, and the
"singleheader-json" target that were added by hand in #4584. The
generator now emits the complete file, so its output differs from the
previous BUILD.bazel only by the three headers. It also resolves the
glob against the project root instead of the working directory and
sorts the list explicitly.
"make BUILD.bazel" is now phony: in a fresh checkout, BUILD.bazel is
not older than the headers, so make considered it up to date, and a
removed header would never trigger a rebuild. "make check-amalgamation"
also checks that BUILD.bazel is up to date.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Check in CI that BUILD.bazel is up to date
The "Check amalgamation" workflow now also regenerates BUILD.bazel, so a
pull request that adds, renames, or removes a header without updating
the Bazel header list fails, and the attached amalgamation.patch
contains the fix. The failure comment and the contribution guidelines
mention the new check, and the comment now links to the existing
"Amalgamate the source code" section instead of the "Files to change"
anchor that was removed in #4560.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Niels Lohmann
Jeremy Nimmer
Vertexwahn