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110 lines
2.8 KiB
Markdown
110 lines
2.8 KiB
Markdown
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# basic_json::sax_parse
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```cpp
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// (1)
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template <typename InputType, typename SAX>
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static bool sax_parse(InputType&& i,
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SAX* sax,
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input_format_t format = input_format_t::json,
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const bool strict = true,
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const bool ignore_comments = false);
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// (2)
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template<class IteratorType, class SAX>
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static bool sax_parse(IteratorType first, IteratorType last,
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SAX* sax,
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input_format_t format = input_format_t::json,
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const bool strict = true,
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const bool ignore_comments = false);
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```
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Read from input and generate SAX events
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1. Read from a compatible input.
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2. Read from a pair of character iterators
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The value_type of the iterator must be a integral type with size of 1, 2 or 4 bytes, which will be interpreted
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respectively as UTF-8, UTF-16 and UTF-32.
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The SAX event lister must follow the interface of `json_sax`.
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## Template parameters
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`InputType`
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: A compatible input, for instance:
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- an `std::istream` object
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- a `FILE` pointer
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- a C-style array of characters
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- a pointer to a null-terminated string of single byte characters
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- an object `obj` for which `begin(obj)` and `end(obj)` produces a valid pair of
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iterators.
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`IteratorType`
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: Description
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`SAX`
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: Description
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## Parameters
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`i` (in)
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: Input to parse from.
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`sax` (in)
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: SAX event listener
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`format` (in)
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: the format to parse (JSON, CBOR, MessagePack, or UBJSON) (optional, `input_format_t::json` by default), see
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[`input_format_t`](input_format_t.md) for more information
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`strict` (in)
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: whether the input has to be consumed completely (optional, `#!cpp true` by default)
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`ignore_comments` (in)
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: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
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(`#!cpp false`); (optional, `#!cpp false` by default)
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`first` (in)
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: iterator to start of character range
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`last` (in)
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: iterator to end of character range
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## Return value
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return value of the last processed SAX event
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## Exception safety
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## Complexity
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Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the SAX
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consumer `sax` has a super-linear complexity.
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## Notes
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A UTF-8 byte order mark is silently ignored.
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## Examples
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??? example
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The example below demonstrates the `sax_parse()` function reading from string and processing the events with a
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user-defined SAX event consumer.
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```cpp
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--8<-- "examples/sax_parse.cpp"
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```
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Output:
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```json
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--8<-- "examples/sax_parse.output"
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```
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## Version history
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- Added in version 3.2.0.
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- Ignoring comments via `ignore_comments` added in version 3.9.0.
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