docs: new design for the documentation site (#5934)

* docs: new design for the documentation site

Apply the brand to the Material for MkDocs site: Inter and JetBrains Mono
served by the site (upright and real italic), brand colours, blue header band
with the syntax pattern, wordmark in the header, new home page (hero, cards,
animated feature tour), 404 page, polish for tabs, search, footer, focus
rings, tables and code blocks, and theme features (code copy, previous/next
footer, TOC follow, search suggestions).

Draw the number railroad diagram, the parser callback events and the iterator
illustrations as inline SVGs that follow the light and dark scheme. The
generator scripts are in docs/mkdocs/scripts/figures; the feature slideshow
(json-light.svg, json-dark.svg, replacing json.gif on the home page) is built
by docs/mkdocs/scripts/slideshow. Decision nodes in five flowcharts become
hexagons, which need far less room.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: add figures, table captions and a macro chooser

- Figures with numbered captions: SAX stepper, json_view layout and edit
  stepper, exception map, JSON pointer and patch walkers, QA pipeline,
  scaling and binary size charts, roadmap lanes, release timeline,
  integration decision tree and namespace builder
- Table captions (nj-table-caption) on 9 pages
- Compile times: modules and PCH charts, filesystem section, re-measured
  Figure 1, links between features/modules.md and compile_times.md
- Interactive macro chooser for features/arbitrary_types.md
- Link check: exclude URLs that answer the plugin with 400/401/419 or are
  dead (customers.md)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: macro chooser generates adl_serializer for non-default-constructible types

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: cross-link concept pages and API pages in See also sections

Add See also links in both directions between the concept pages (features,
home, integration) and the API pages, write API links in code font, give every
entry a comment after a dash, and show the callback event figure on the parser
callbacks page.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* docs: address review comments on the new design

- Home: add a "Latest release" button
- Sponsors: update the list and group it by tier
- Features: list all feature pages on the index page
- Releases: add highlights per release, link the 4.0 roadmap, add the first commit to the timeline
- Exceptions: prefix all example messages with the exception name
- API: no code font for format names in the See also links of the to_/from_ pages
- Merge Patch: show the document before, the patch, and the result
- Replace "--" with typographic dashes, mark external links with an icon, center Mermaid diagrams

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
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@@ -9,7 +9,7 @@ static bool accept(InputType&& input,
Checks whether the input is valid JSON, accepting and rejecting exactly what
[`BasicJsonType::accept()`](../basic_json/accept.md) does, with the same options. Unlike [`parse()`](parse.md), this
function never throws an exception for invalid input, and the returned `#!cpp bool` is the only result -- no document
function never throws an exception for invalid input, and the returned `#!cpp bool` is the only result — no document
is returned.
The result is the same as that of `BasicJsonType::accept()` by design; the difference is how the check is made. This
@@ -69,8 +69,9 @@ compile; see [`parse`](parse.md#notes).
## See also
- [parse](parse.md) - deserialize from a compatible input
- [`parse`](parse.md) - deserialize from a compatible input
- [`BasicJsonType::accept`](../basic_json/accept.md) - the corresponding function of `basic_json`
- [Zero-copy JSON views](../../features/json_view.md#what-is-the-same-as-parse) - how parsing a document differs from, and matches, basic_json::parse
## Version history
@@ -50,8 +50,9 @@ Constant.
## See also
- [parse](parse.md) - deserialize from a compatible input
- [is_discarded](is_discarded.md) - return whether the last parse failed
- [`parse`](parse.md) - deserialize from a compatible input
- [`is_discarded`](is_discarded.md) - return whether the last parse failed
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history
@@ -54,7 +54,7 @@ has `erase`; calling it on a read-only `basic_json_document` fails to compile (`
## Exceptions
1. Throws [`type_error.307`](../../home/exceptions.md#jsonexceptiontype_error307) if `object` is not an object -- the
1. Throws [`type_error.307`](../../home/exceptions.md#jsonexceptiontype_error307) if `object` is not an object — the
same message [`BasicJsonType::erase`](../basic_json/erase.md) throws for the same type.
2. Throws `type_error.307` if `array` is not an array. Throws
[`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative, or if
@@ -86,12 +86,12 @@ always starts from this document's own [`root()`](root.md).
!!! info "Duplicate keys"
Overload 1. removes *every* member with `key`, not just the first -- unlike [`set`](set.md), which assigns the
Overload 1. removes *every* member with `key`, not just the first — unlike [`set`](set.md), which assigns the
first occurrence and drops the rest. This is why it returns a count rather than a single view: there may be
more than one member removed, or none.
Like [`set`](set.md) and [`push_back`](push_back.md), `erase` never moves an element's *value*: a view still
referring to a removed member or element keeps showing what it last held (see [Edits](index.md#edits)) -- it just no
referring to a removed member or element keeps showing what it last held (see [Edits](index.md#edits)) — it just no
longer appears when `array`/`object` is read, dumped, or iterated. What does change is the container's sequence of
*links* to its elements: removing an element of `array` (2.) shifts the links to the elements after it by one, as
[`insert`](insert.md) does in the other direction. *Every* iterator already taken over `array`/`object` is invalidated
@@ -101,8 +101,8 @@ by an erase, not only those at or after the removed element, since the container
??? example
The example below drops a deprecated field and a decommissioned entry from a configuration document -- using all
three overloads -- and shows what stays intact that would not with a plain `json`/`ordered_json` value: the order
The example below drops a deprecated field and a decommissioned entry from a configuration document — using all
three overloads — and shows what stays intact that would not with a plain `json`/`ordered_json` value: the order
of the fields around the ones removed, and the exact spelling of a number that was never touched.
```cpp
@@ -117,12 +117,13 @@ by an erase, not only those at or after the removed element, since the container
## See also
- [insert](insert.md) - insert an element into an array
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [push_back](push_back.md) - append to an array
- [root](root.md) - the view of the root value, the starting point of overload 3
- [`insert`](insert.md) - insert an element into an array
- [`set`](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`push_back`](push_back.md) - append to an array
- [`root`](root.md) - the view of the root value, the starting point of overload 3
- [`BasicJsonType::erase`](../basic_json/erase.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history
@@ -109,7 +109,7 @@ points apply to every edit:
anything `BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
- [`dump()`](../basic_json_view/dump.md) writes an edited document with members in document order, new members at
the end, and, with [`number_format::source`](../basic_json_view/number_format.md), keeps the spelling of every
number that was not itself edited -- see [Editing a document](../../features/json_view.md#editing-a-document) for
number that was not itself edited — see [Editing a document](../../features/json_view.md#editing-a-document) for
why this matters.
- [`read()`](read.md) discards all edits, [`shrink_to_fit()`](shrink_to_fit.md) does not move the node index once
there are edits, and [`memory_usage()`](memory_usage.md) includes the memory edits use.
@@ -119,9 +119,9 @@ points apply to every edit:
## See also
- [Zero-copy JSON views](../../features/json_view.md) - guide to documents and views
- [**basic_json_view**](../basic_json_view/index.md) - the non-owning handle to a value in a document
- [**json_document**](../json_document.md) and [**json_editable_document**](../json_editable_document.md) - the default specializations
- [**materialize**](../basic_json_view/materialize.md) - build a `basic_json` value from a view
- [`basic_json_view`](../basic_json_view/index.md) - the non-owning handle to a value in a document
- [`json_document`](../json_document.md) - and [`json_editable_document`](../json_editable_document.md) - the default specializations
- [`materialize`](../basic_json_view/materialize.md) - build a `basic_json` value from a view
## Version history
@@ -13,8 +13,8 @@ Inserts `value` into `array` as a new element before position `idx`, which must
[`push_back`](push_back.md), a [null](../basic_json_view/is_null.md) `array` does *not* first become an empty array:
`array` must already be an array.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document — read-only or
editable, and it does not have to be `array`'s own document — which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
@@ -44,16 +44,16 @@ a view of the new element, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
Basic exception safety: `value` is fully encoded — including the checks below — into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave `array` already
for the encoding that is not reclaimed. A failure of a later allocation — while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) — can still leave `array` already
switched to that layout even though `value` itself was not inserted.
## Exceptions
Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if `array` is not an array -- the same
Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if `array` is not an array — the same
message [`BasicJsonType::insert`](../basic_json/insert.md) throws for the same type; a null `array` throws this too
(see above). Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative,
or if `#!cpp idx > array.size()`. Throws
@@ -62,7 +62,7 @@ document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
binary value — `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
@@ -76,8 +76,8 @@ grows in amortized constant time; inserting before the end within that block sti
## Notes
Like [`set`](set.md) on a member or an element, `insert` never moves an existing *element's value* -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across an
Like [`set`](set.md) on a member or an element, `insert` never moves an existing *element's value* — only where
`array`'s *links* to its elements live — so a view of an existing element of `array` stays valid across an
`insert`, and keeps referring to the same element even though its index shifts. Any iterator already taken over
`array` is invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across
an edit in general.
@@ -88,7 +88,7 @@ an edit in general.
The example below inserts a step into the middle of a deployment plan, without touching the steps that come
after it, and shows that a view taken before the insert keeps referring to the same element even though its
index shifts -- something a plain `json`/`ordered_json` array, or its `std::vector`-based storage, has no
index shifts — something a plain `json`/`ordered_json` array, or its `std::vector`-based storage, has no
equivalent for.
```cpp
@@ -103,11 +103,12 @@ an edit in general.
## See also
- [push_back](push_back.md) - append to an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`push_back`](push_back.md) - append to an array
- [`erase`](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [`set`](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`BasicJsonType::insert`](../basic_json/insert.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history
@@ -41,8 +41,9 @@ When the document is discarded, [`root()`](root.md) returns a discarded view (it
## See also
- [parse](parse.md) - deserialize from a compatible input
- [is_discarded (basic_json_view)](../basic_json_view/is_discarded.md) - return whether a view is invalid
- [`parse`](parse.md) - deserialize from a compatible input
- [`basic_json_view::is_discarded`](../basic_json_view/is_discarded.md) - return whether a view is invalid
- [Zero-copy JSON views](../../features/json_view.md#what-is-the-same-as-parse) - how a discarded document arises
## Version history
@@ -16,14 +16,14 @@ static basic_json_document load(std::vector<std::uint8_t>&& image,
1. Reads an image [`save()`](save.md) wrote, from a pointer and a byte count. The image is **borrowed**: `image`
must stay alive and unchanged for as long as the returned document, and any view taken from it, is used.
2. Reads an image from a `#!cpp std::vector`. Also **borrowed** -- equivalent to overload 1 called with
2. Reads an image from a `#!cpp std::vector`. Also **borrowed** — equivalent to overload 1 called with
`#!cpp image.data()` and `#!cpp image.size()`.
3. Reads an image, keeping the vector instead of copying it: `image` is moved into the document (no copy), which
then owns it for as long as it needs the text and the decoded strings. [`owns_source()`](owns_source.md) is
`#!cpp true` afterward.
In every overload, the node index is copied into storage the document itself owns -- so that it is properly aligned,
and, for an [editable](index.md#edits) document, can be edited -- while the text and the decoded strings stay in
In every overload, the node index is copied into storage the document itself owns — so that it is properly aligned,
and, for an [editable](index.md#edits) document, can be edited — while the text and the decoded strings stay in
`image`. The hash indexes [large objects](../../features/json_view.md) use for lookup are rebuilt, exactly as after
parsing.
@@ -49,7 +49,7 @@ Overloads 1 and 2 give the strong guarantee: `image` is only read, never written
caller's buffer untouched.
Overload 3 moves `image` into the document *before* validating it, so that a good image is kept without a copy. If
loading then fails, the partially built document -- and the vector now inside it -- is discarded along with the
loading then fails, the partially built document — and the vector now inside it — is discarded along with the
exception, and `image` itself is left **empty**, not restored to what was passed in. Move a copy in instead, or
validate with overload 2 first, if the original vector must survive a failed load.
@@ -63,7 +63,7 @@ Throws [`parse_error.116`](../../home/exceptions.md#jsonexceptionparse_error116)
| `too short` | `image` is `#!cpp nullptr`, or `size` is smaller than the 64-byte header |
| `unknown format` | the header's magic bytes or version do not match, or a reserved header field is not zero |
| `sizes out of range` | the node count, text size, or decoded-string size the header describes does not fit `size`, or the `#!cpp '\0'` after the text or after the decoded strings is missing |
| `the check failed` | `check` is not `#!cpp image_check::none`, and the image fails it -- see [`image_check`](#image_check) |
| `the check failed` | `check` is not `#!cpp image_check::none`, and the image fails it — see [`image_check`](#image_check) |
!!! failure "Example messages"
@@ -116,7 +116,7 @@ How thoroughly `load()` validates `image` before trusting it.
token is well-formed and matches the value stored for it. Strings and float tokens may share a range only if the
ranges are identical (as nodes that share a value do), and never overlap otherwise. Reading and serializing a
checked image is safe and always produces valid JSON, exactly as for a parsed document. This is the right choice for
an image from anything you do not fully control -- a file, a cache shared with other processes, a peer on the
an image from anything you do not fully control — a file, a cache shared with other processes, a peer on the
network.
`bounds`
@@ -136,7 +136,7 @@ How thoroughly `load()` validates `image` before trusting it.
your own memory.
**Lifetime.** Overloads 1 and 2 borrow `image`: it must stay alive and byte-for-byte unchanged for as long as the
returned document, and any [view](../basic_json_view/index.md) taken from it, is used -- exactly like a document
returned document, and any [view](../basic_json_view/index.md) taken from it, is used — exactly like a document
[`parse()`](parse.md) borrowed its input for. Overload 3 avoids this by keeping the vector itself; see
[`owns_source`](owns_source.md).
@@ -145,7 +145,7 @@ returned document, and any [view](../basic_json_view/index.md) taken from it, is
The image format is versioned but not yet stable, and may change in an incompatible way before it is declared
stable; `load()` already rejects an image written by a different format version with `parse_error.116`
("unknown format"). Use images to cache a document within one build of the library, or to hand one to another
process running the *same* build on the *same* (little-endian) machine -- not as a long-term storage format.
process running the *same* build on the *same* (little-endian) machine — not as a long-term storage format.
## Examples
@@ -154,8 +154,8 @@ returned document, and any [view](../basic_json_view/index.md) taken from it, is
The example below saves a parsed document as an image, checks that `load()` reproduces the original
[`dump()`](../basic_json_view/dump.md) without parsing, and shows the difference between
`load(std::move(image))` (owned) and `load(image)` (borrowed). It then damages one byte of the image and shows
`image_check::full` rejecting it with `parse_error.116`, while `image_check::bounds` -- meant for a cache the
process already trusts -- still reads it without going out of bounds.
`image_check::full` rejecting it with `parse_error.116`, while `image_check::bounds` — meant for a cache the
process already trusts — still reads it without going out of bounds.
```cpp
--8<-- "examples/basic_json_document__load.cpp"
@@ -169,9 +169,9 @@ returned document, and any [view](../basic_json_view/index.md) taken from it, is
## See also
- [save](save.md) - write the document as an image
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [parse](parse.md) - deserialize from JSON text instead of an image
- [`save`](save.md) - write the document as an image
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`parse`](parse.md) - deserialize from JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
## Version history
@@ -23,7 +23,7 @@ Constant.
The exact value depends on the platform, the allocator, and the library's own layout, and may change between
versions; do not rely on it being a specific number, and do not compare it across different builds or platforms.
Compare it for the same document over time, or between documents built with the same binary, instead -- for instance
Compare it for the same document over time, or between documents built with the same binary, instead — for instance
to observe the effect of [`shrink_to_fit()`](shrink_to_fit.md).
## Examples
@@ -42,8 +42,9 @@ to observe the effect of [`shrink_to_fit()`](shrink_to_fit.md).
## See also
- [node_count](node_count.md) - the number of index entries
- [shrink_to_fit](shrink_to_fit.md) - release unused index capacity
- [`node_count`](node_count.md) - the number of index entries
- [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity
- [Zero-copy JSON views](../../features/json_view.md#the-idea) - the flat node index and its memory
## Version history
@@ -41,8 +41,9 @@ strings and, for an owned document, the text).
## See also
- [memory_usage](memory_usage.md) - the number of bytes held by the document
- [shrink_to_fit](shrink_to_fit.md) - release unused index capacity
- [`memory_usage`](memory_usage.md) - the number of bytes held by the document
- [`shrink_to_fit`](shrink_to_fit.md) - release unused index capacity
- [Zero-copy JSON views](../../features/json_view.md#the-idea) - the flat node index and its memory
## Version history
@@ -40,9 +40,10 @@ document (`#!cpp owns_source() == false`) is only valid while the buffer it was
## See also
- [parse](parse.md) - deserialize from a compatible input
- [parse_copy](parse_copy.md) - deserialize a copy of a compatible input, always owned
- [source](source.md) - the parsed text
- [`parse`](parse.md) - deserialize from a compatible input
- [`parse_copy`](parse_copy.md) - deserialize a copy of a compatible input, always owned
- [`source`](source.md) - the parsed text
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history
@@ -24,7 +24,7 @@ Both overloads accept the same JSON text as [`BasicJsonType::parse()`](../basic_
the input) instead of a tree of `BasicJsonType` values. They accept every input `BasicJsonType::parse()` takes, and in
addition a pointer to a null-terminated wide string (which `BasicJsonType::parse()` rejects). Contiguous inputs of
single-byte characters that stay alive can be borrowed; all others (streams, `#!cpp FILE*`, wide characters, which
must be converted to UTF-8, and non-contiguous iterators) are read into a copy that the document owns -- see the
must be converted to UTF-8, and non-contiguous iterators) are read into a copy that the document owns — see the
Notes. Use [`parse_copy()`](parse_copy.md) to get an owned copy of a borrowable input
as well.
@@ -82,8 +82,8 @@ discarded; see [`is_discarded`](is_discarded.md).
## Exceptions
Throws the same exception [`BasicJsonType::parse()`](../basic_json/parse.md) throws for the same input and options --
the same exception id, message, and position -- because on a failing input the library's own parser is run on the
Throws the same exception [`BasicJsonType::parse()`](../basic_json/parse.md) throws for the same input and options —
the same exception id, message, and position — because on a failing input the library's own parser is run on the
same bytes to produce the diagnostic. This replay runs only for a failing input, and costs about a lexing pass up to
the error (its SAX handler builds no values); with `allow_exceptions` set to `#!cpp false`, it is skipped and a
discarded document is returned instead. Additionally throws
@@ -100,7 +100,7 @@ Linear in the length of the input.
| `input` | ownership |
|--------------------------------------------------------------------------------------|--------------------------------------------------------------|
| lvalue byte container (`std::string`, `std::vector<char>`, ...), `std::string_view`, C string, character array | **borrowed** -- `input` must outlive the document |
| lvalue byte container (`std::string`, `std::vector<char>`, ...), `std::string_view`, C string, character array | **borrowed** — `input` must outlive the document |
| non-const rvalue `#!cpp std::string` | **owned**, moved in without a copy |
| other rvalue byte container (including a `#!cpp const` rvalue `#!cpp std::string`) | **owned**, copied |
| stream, `#!cpp FILE*`, wide characters, or anything else read through the general input adapter | **owned**, read into a buffer (a stream is read to its end) |
@@ -117,8 +117,8 @@ See [`owns_source`](owns_source.md) to check which happened after a call, and th
**Numbers.** As for [`BasicJsonType::parse()`](../basic_json/parse.md), an integer literal too large for the 64-bit
integer type becomes a floating-point value.
**No lengths.** An integer argument that is not a `#!cpp bool` where the flags are expected -- for example
`#!cpp parse(ptr, len)` -- does not compile (the overload is deleted). Such a call would convert `len` to
**No lengths.** An integer argument that is not a `#!cpp bool` where the flags are expected — for example
`#!cpp parse(ptr, len)` — does not compile (the overload is deleted). Such a call would convert `len` to
`allow_exceptions` and read `ptr` as a null-terminated string, past the end of a buffer that has none. To parse a
buffer of a given length, pass a pair of pointers: `#!cpp parse(ptr, ptr + len)`. The same holds for
[`parse_copy`](parse_copy.md), [`accept`](accept.md), and [`read`](read.md).
@@ -151,11 +151,11 @@ buffer of a given length, pass a pair of pointers: `#!cpp parse(ptr, ptr + len)`
## See also
- [parse_copy](parse_copy.md) - deserialize a copy of a compatible input
- [accept](accept.md) - check whether the input is valid JSON
- [read](read.md) - (re-)parse into this document, reusing its memory
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [load](load.md) - read a document from an image instead of parsing JSON text
- [`parse_copy`](parse_copy.md) - deserialize a copy of a compatible input
- [`accept`](accept.md) - check whether the input is valid JSON
- [`read`](read.md) - (re-)parse into this document, reusing its memory
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`load`](load.md) - read a document from an image instead of parsing JSON text
- [`BasicJsonType::parse`](../basic_json/parse.md) - the corresponding function of `basic_json`
## Version history
@@ -72,8 +72,9 @@ compile; see [`parse`](parse.md#notes).
## See also
- [parse](parse.md) - deserialize from a compatible input, borrowing it where possible
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [`parse`](parse.md) - deserialize from a compatible input, borrowing it where possible
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - borrowing or copying the source text
## Version history
@@ -8,8 +8,8 @@ view_type push_back(view_type array, V&& value);
Appends `value` as a new last element of `array`. A [null](../basic_json_view/is_null.md) `array` first becomes an
empty array, the same way [`set`](set.md) turns a null `object` into an empty object.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document — read-only or
editable, and it does not have to be `array`'s own document — which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
@@ -35,23 +35,23 @@ a view of the new last element of `array`, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
Basic exception safety: `value` is fully encoded — including the checks below — into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave a partial effect, such
for the encoding that is not reclaimed. A failure of a later allocation — while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) — can still leave a partial effect, such
as a null `array` argument already turned into an empty array even though `value` itself was not appended.
## Exceptions
Throws [`type_error.308`](../../home/exceptions.md#jsonexceptiontype_error308) if `array` is neither an array nor
null -- the same message [`BasicJsonType::push_back`](../basic_json/push_back.md) throws for the same type. Throws
null — the same message [`BasicJsonType::push_back`](../basic_json/push_back.md) throws for the same type. Throws
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a *different* document.
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
binary value — `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
@@ -59,14 +59,14 @@ not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/d
Amortized constant, plus time linear in the size of `value` to encode it into the document's storage (constant for
a scalar, linear in the number of nested values for an array or object): the elements of `array` move to a growable
block of links the first time it is appended to (or [`set`](set.md) on), and that block itself grows -- doubling its
capacity, so the cost of growing it amortizes to constant per element -- only once it runs out of room. See
block of links the first time it is appended to (or [`set`](set.md) on), and that block itself grows — doubling its
capacity, so the cost of growing it amortizes to constant per element — only once it runs out of room. See
[Notes](#notes).
## Notes
Like [`set`](set.md) on a member or an element, `push_back` never moves an existing element itself -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across a
Like [`set`](set.md) on a member or an element, `push_back` never moves an existing element itself — only where
`array`'s *links* to its elements live — so a view of an existing element of `array` stays valid across a
`push_back`, but any iterator already taken over `array` is invalidated, since it was walking the old layout. See
[Edits](index.md#edits) for what stays valid across an edit in general.
@@ -90,12 +90,13 @@ Like [`set`](set.md) on a member or an element, `push_back` never moves an exist
## See also
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [insert](insert.md) - insert an element into an array before a given position
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value
- [`set`](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`insert`](insert.md) - insert an element into an array before a given position
- [`erase`](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [`root`](root.md) - the view of the root value
- [`BasicJsonType::push_back`](../basic_json/push_back.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Zero-copy JSON views](../../features/json_view.md#editing-a-document) - what an edit guarantees and costs
## Version history
@@ -43,7 +43,7 @@ Linear in the length of the input.
## Notes
Every view taken from `#!cpp *this` before the call -- including the previous [`root()`](root.md) -- is invalidated,
Every view taken from `#!cpp *this` before the call — including the previous [`root()`](root.md) — is invalidated,
whether or not the new parse succeeds; take fresh views from [`root()`](root.md) afterward.
`input` is borrowed or owned by the same rules as [`parse()`](parse.md#notes); a document can borrow on one call and
@@ -78,9 +78,10 @@ compile; see [`parse`](parse.md#notes).
## See also
- [parse](parse.md) - deserialize from a compatible input
- [root](root.md) - the view of the root value
- [load](load.md) - read a document from an image instead of parsing JSON text
- [`parse`](parse.md) - deserialize from a compatible input
- [`root`](root.md) - the view of the root value
- [`load`](load.md) - read a document from an image instead of parsing JSON text
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - reusing a document and what it invalidates
## Version history
@@ -37,8 +37,8 @@ auto v = doc.root();
```
`root()` is a cheap handle into the document's index, not a copy of anything; call it as often as needed. The
returned view is valid under the same conditions as any other view of the document -- see
[Object inspection](../basic_json_view/index.md) -- in particular, it is invalidated by the next
returned view is valid under the same conditions as any other view of the document — see
[Object inspection](../basic_json_view/index.md) — in particular, it is invalidated by the next
[`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document. A view can dangle, like a
`#!cpp std::string_view`; see [Ownership and lifetime](../../features/json_view.md#ownership-and-lifetime).
@@ -58,8 +58,8 @@ returned view is valid under the same conditions as any other view of the docume
## See also
- [is_discarded](is_discarded.md) - return whether the last parse failed
- [materialize](../basic_json_view/materialize.md) - build the `BasicJsonType` value of a subtree
- [`is_discarded`](is_discarded.md) - return whether the last parse failed
- [`materialize`](../basic_json_view/materialize.md) - build the `BasicJsonType` value of a subtree
## Version history
@@ -6,13 +6,13 @@ std::vector<std::uint8_t> save() const;
Writes the document as an *image*: a byte buffer that [`load`](load.md) reads back without parsing. The image holds
the node index, the source text (plus, for an edited document, the number tokens edits wrote), and the decoded
strings (plus the strings edits wrote) -- everything [`root()`](root.md) needs, with nothing left to parse.
strings (plus the strings edits wrote) — everything [`root()`](root.md) needs, with nothing left to parse.
An edited document is written in its *current* state, with its values in document order, the way the library's own
parser would have produced them for that JSON text: a member [`set`](set.md) added goes at the end, an
[`erase`](erase.md)d member leaves no trace, and a float that is not finite (NaN or positive/negative infinity)
becomes null, the same substitution [`dump()`](../basic_json_view/dump.md) makes. The same document always saves to
the same bytes -- also across `BasicJsonType` and the [`view_mode`](../view_mode.md), since the image reflects document order and
the same bytes — also across `BasicJsonType` and the [`view_mode`](../view_mode.md), since the image reflects document order and
values only, not which specialization produced them.
## Return value
@@ -28,11 +28,11 @@ exactly as it was, and the partially built image is discarded with the exception
## Exceptions
Throws [`type_error.320`](../../home/exceptions.md#jsonexceptiontype_error320) if the document is
[discarded](is_discarded.md) -- a default-constructed document, or one a failed [`parse()`](parse.md)/
[discarded](is_discarded.md) — a default-constructed document, or one a failed [`parse()`](parse.md)/
[`read()`](read.md) with `allow_exceptions == false` left discarded.
Throws [`out_of_range.416`](../../home/exceptions.md#jsonexceptionout_of_range416) if the node count, the text, or
the decoded strings of the image would individually reach 4 GiB -- the same 32-bit offsets
the decoded strings of the image would individually reach 4 GiB — the same 32-bit offsets
[`parse()`](parse.md#exceptions) and, for edits, [`set`](set.md)/[`push_back`](push_back.md) are already limited to.
!!! failure "Example messages"
@@ -55,13 +55,13 @@ up in the image.
and the sizes of the text and the decoded strings, all little-endian), followed by the nodes
([16 bytes each](../../home/architecture.md#node-index-of-json-views)), the text and a `#!cpp '\0'`, and the decoded
strings and a `#!cpp '\0'`. [`load`](load.md) checks the header, and the sizes it describes, before reading anything
else -- see [`load`'s Exceptions](load.md#exceptions).
else — see [`load`'s Exceptions](load.md#exceptions).
!!! warning "Experimental"
The image format is versioned but not yet stable: it may change in an incompatible way before it is declared
stable. Use images to cache a document within one build of the library, or to hand one to another process running
the *same* build on the *same* (little-endian) machine -- not as a long-term storage format. Keep the original
the *same* build on the *same* (little-endian) machine — not as a long-term storage format. Keep the original
JSON text if you need to read a saved document back with a future library version.
**Little-endian targets only.** The image is written as raw little-endian bytes, with no byte-swapping. On a
@@ -72,8 +72,8 @@ big-endian reader could not interpret correctly.
??? example "Caching a parsed document as an image"
The example below saves a parsed configuration as an image -- the way a service might cache one to answer later
requests without parsing the text again -- and confirms that loading it back gives exactly the same result as
The example below saves a parsed configuration as an image — the way a service might cache one to answer later
requests without parsing the text again — and confirms that loading it back gives exactly the same result as
parsing did, and that saving is deterministic.
```cpp
@@ -88,8 +88,8 @@ big-endian reader could not interpret correctly.
## See also
- [load](load.md) - read an image written by `save()`
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [`load`](load.md) - read an image written by `save()`
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document to JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
+20 -20
View File
@@ -23,8 +23,8 @@ has `set`; calling it on a read-only `basic_json_document` fails to compile (`#!
1. Replaces the value `target` refers to with `value`.
2. Sets the member `key` of the object `object` to `value`: assigns it if `object` already has a member with this
key -- the first one, should the key occur more than once, and the later duplicates are then dropped (see the
[Notes](#notes) below) -- or appends a new member at the end otherwise. A [null](../basic_json_view/is_null.md)
key — the first one, should the key occur more than once, and the later duplicates are then dropped (see the
[Notes](#notes) below) — or appends a new member at the end otherwise. A [null](../basic_json_view/is_null.md)
`object` first becomes an empty object.
3. Assigns `value` to the element at index `idx` of the array `array`, which must already exist (`#!cpp idx <
array.size()`).
@@ -37,7 +37,7 @@ has `set`; calling it on a read-only `basic_json_document` fails to compile (`#!
null values up to that index), an object otherwise. An empty `ptr` sets [`root()`](root.md) itself, as in 1.
In every overload, `value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any*
document -- read-only or editable, and it does not have to be `target`'s/`object`'s/`array`'s own document -- which
document — read-only or editable, and it does not have to be `target`'s/`object`'s/`array`'s own document — which
is copied so that nothing is shared with the source document afterward; a `BasicJsonType` value; or anything
`BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
@@ -82,11 +82,11 @@ is copied so that nothing is shared with the source document afterward; a `Basic
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
Basic exception safety: `value` is fully encoded — including the checks below — into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while an edited array or object switches
from its parsed layout to a growable block, see [Notes](#notes) -- can still leave a partial effect, such as a
for the encoding that is not reclaimed. A failure of a later allocation — while an edited array or object switches
from its parsed layout to a growable block, see [Notes](#notes) — can still leave a partial effect, such as a
[null](../basic_json_view/is_null.md) `object`/`array` argument already turned into an empty object/array even
though `value` itself was not linked in. Likewise, a failure of `value` in 4. leaves a null parent that is set with an
index beyond 0 already filled with the null values before the index.
@@ -95,14 +95,14 @@ index beyond 0 already filled with the null values before the index.
1. Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view, or a [discarded](../basic_json/is_discarded.md)
`BasicJsonType` value (e.g. `#!cpp BasicJsonType(value_t::discarded)`) -- an object or array `value`, of either
`BasicJsonType` value (e.g. `#!cpp BasicJsonType(value_t::discarded)`) — an object or array `value`, of either
kind, is fine and is encoded as a whole subtree.
2. Throws [`type_error.305`](../../home/exceptions.md#jsonexceptiontype_error305) if `object` is neither an object
nor null -- the same message [`operator[]`](../basic_json_view/operator%5B%5D.md) throws for a string argument on
nor null — the same message [`operator[]`](../basic_json_view/operator%5B%5D.md) throws for a string argument on
such a value. Throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `key` is not
valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
Also throws what 1. throws for `value`.
3. Throws `type_error.305` if `array` is not an array -- the same message `operator[]` throws for a numeric argument
3. Throws `type_error.305` if `array` is not an array — the same message `operator[]` throws for a numeric argument
on such a value. Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is
negative, or if `#!cpp idx >= array.size()`. Also throws what 1. throws for `value`.
4. Throws what [`at`](../basic_json_view/at.md) throws (overload 3) for resolving `ptr`'s parent, except that a
@@ -121,7 +121,7 @@ index beyond 0 already filled with the null values before the index.
Also throws what 1. throws for `value`.
Every overload also throws [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or
contains) a binary value -- `BasicJsonType` can hold one, but a `json_document` cannot -- and
contains) a binary value — `BasicJsonType` can hold one, but a `json_document` cannot — and
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a
*different* document (overloads 1-3 only; overload 4 always starts from this document's own [`root()`](root.md)).
@@ -132,7 +132,7 @@ document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_d
number of nested values for an array or object. If `target` is itself an array or object that spans more than one
node in its parent's original, unedited layout, and `value` is a scalar, replacing it additionally costs time
linear in the size of the document, the *first* time (the parent of `target` is looked up from
[`root()`](root.md), and then switches to links) -- see [Notes](#notes). Once the parent has links, `target` is
[`root()`](root.md), and then switches to links) — see [Notes](#notes). Once the parent has links, `target` is
replaced in constant time: setting every element of a large array one after the other is linear overall. To avoid
the lookup altogether, use 3. (or 2. for an object), which know the parent.
2. Linear in the number of members of `object`, to find an existing member with `key`, plus the complexity of 1. for
@@ -147,7 +147,7 @@ document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_d
!!! info "Duplicate keys"
If `object` already has more than one member with `key` (2.), the *first* one is assigned `value` and every
later member with the same key is removed -- so that a lookup, an iteration, and
later member with the same key is removed — so that a lookup, an iteration, and
[`materialize()`](../basic_json_view/materialize.md) of `object` afterward all agree on a single value for
`key`, the same way [`operator[]`](../basic_json_view/operator%5B%5D.md) already picks the first occurrence of a
duplicate key for reading. See the [Notes on duplicate keys](../basic_json_view/operator%5B%5D.md#notes) of
@@ -156,8 +156,8 @@ document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_d
Setting a member (2.) or an element (3., through 4.) of an array or object whose elements have not been edited
before switches it from its parsed layout to a growable block holding links to its elements; a later
[`push_back`](push_back.md) or `set` on the same container reuses that block, growing it (amortized constant time)
only once it runs out of room. This never moves an element itself -- only where the container's *links* to its
elements live -- so a view of an element stays valid, but any iterator already taken over the container is
only once it runs out of room. This never moves an element itself — only where the container's *links* to its
elements live — so a view of an element stays valid, but any iterator already taken over the container is
invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across an edit in
general.
@@ -170,8 +170,8 @@ one-node scalar.
??? example "Example: (1)/(2)/(3)/(4) replace a value, set a member, assign an element, set via a JSON pointer"
The example below edits a small configuration document -- replacing a value, adding an object member, assigning
an array element, and reaching a field through a JSON pointer -- and shows what
The example below edits a small configuration document — replacing a value, adding an object member, assigning
an array element, and reaching a field through a JSON pointer — and shows what
[`dump()`](../basic_json_view/dump.md) preserves that is lost once the same edits are made on a `BasicJsonType`
value instead: the order object members were written in, and the exact spelling of a number that was never
touched.
@@ -188,10 +188,10 @@ one-node scalar.
## See also
- [push_back](push_back.md) - append to an array
- [insert](insert.md) - insert an element into an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value, the starting point of overload 4
- [`push_back`](push_back.md) - append to an array
- [`insert`](insert.md) - insert an element into an array
- [`erase`](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [`root`](root.md) - the view of the root value, the starting point of overload 4
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document, keeping an untouched number's
spelling with `#!cpp number_format::source`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
@@ -53,9 +53,10 @@ possible would be an internal optimization only, not a guarantee to rely on.
## See also
- [node_count](node_count.md) - the number of index entries
- [memory_usage](memory_usage.md) - the number of bytes held by the document
- [root](root.md) - the view of the root value
- [`node_count`](node_count.md) - the number of index entries
- [`memory_usage`](memory_usage.md) - the number of bytes held by the document
- [`root`](root.md) - the view of the root value
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - what releasing memory invalidates
## Version history
@@ -40,8 +40,9 @@ is; see [`owns_source`](owns_source.md).
## See also
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [source_offset](../basic_json_view/source_offset.md) - byte offset of a value in the source text
- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`source_offset`](../basic_json_view/source_offset.md) - byte offset of a value in the source text
- [Zero-copy JSON views](../../features/json_view.md#ownership-and-lifetime) - who owns the source text and for how long
## Version history