Commit Graph
6 Commits
Author SHA1 Message Date
Niels Lohmann d71a494367 Fix CI: json_view tests without exceptions, on clang 3.6, and single header
- ci_test_noexceptions: the helpers that compare the exceptions of
  json_document::parse() and json::parse() catch them outside a
  CHECK_THROWS, so with JSON_NOEXCEPTION the first parse error aborted
  the test. Compile those comparisons only with exceptions, as
  unit-class_parser.cpp does.
- ci_test_gcc: -Werror=unused-result for CHECK_THROWS_AS(json_document::
  parse(...)); assign the result to a dummy document.
- ci_test_compilers_clang (3.6): `const json_view invalid;` needs a
  user-provided default constructor there (CWG 253); value-initialize it.
- ci_test_single_header: json_view.hpp now exists as a single header and
  contains the internal view headers, so unit-json_view_builder.cpp
  includes it instead of the detail headers in that mode, and the test
  is built again with the single header.
- Regenerate single_include/nlohmann/json_view.hpp for the builder change
  merged from json-view/08-view-builder.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:58:49 +02:00
Niels Lohmann d8b8c2498f Test the C++11 stand-in for std::string_view of json_view
Six members of string_ref (length, begin, end, operator[], operator!=,
and operator<<) were not reached before C++17, where string_ref is
std::string_view.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:19:13 +02:00
Niels Lohmann 8d3280de1e Classify a NUL inside a string of json_view as a control character
json::parse ends the input at a NUL only between values (where it does
at all); inside a string, a NUL is a control character that must be
escaped. The view reported it as a missing closing quote. (Only the
error code differed: the exception comes from the library parser.)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:19:13 +02:00
Niels Lohmann 118af5015e Test the overflow check of json_view at the largest double
Numbers of more than 19 digits at the boundary of the largest double are
decided by the exact comparison with the midpoint in the overflow check.
The check uses the floating-point type of the document: with float, the
view rejects what parse() rejects (1e39, 3.4028236e38, the midpoint between
the largest float and 2^128), and double documents are not affected.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:19:13 +02:00
Niels Lohmann 9b0b4ff26d Address the clang-tidy findings of the view's parser
- tables as std::array; the frames of the first 64 levels stay a C array
  (not initialized on purpose, NOLINT)
- \u escapes are decoded with the library's hex_codepoint() instead of a
  second table
- the parse failure is private, with an accessor; the special member
  functions of the builder are all declared
- no nested conditional operators; explicit parentheses; a repeated
  branch body merged; auto for casts
- the test's C arrays, fixed seed, and escaped literals are marked, as in
  the other tests

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:19:13 +02:00
Niels Lohmann ad82821c89 Add the one-pass parser of json_view (internal)
The builder parses JSON text in one pass into the node index: strings and
numbers stay in the source (escaped strings are decoded into an arena),
integers are converted while their digits are in cache, and floats keep
their digit layout for a later conversion. It accepts exactly what
json::parse accepts, for every combination of comments and trailing commas,
with and without a terminating NUL, and with JSON_STRICT_NUL_HANDLING.

Parse state lives in a local cursor whose address never escapes, so that it
stays in registers; out-of-line helpers (errors, regrowth, escapes,
comments) are members of the builder and get the positions they need. The
value dispatch is expanded once for array elements and once for member
values. Literals are compared with memcmp and words read in a fixed byte
order, so nothing depends on the platform's byte order. Error messages come
with the public classes.

Tests (unit-json_view_builder.cpp): accept/reject and values against
json::parse for handwritten, generated, and damaged documents under all
option combinations, from std::string and from exact-size buffers (no read
past the input under AddressSanitizer), deep nesting up to 100,000 levels,
NUL/BOM/whitespace cases, and the test-suite files.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:19:13 +02:00