Struct LowLevelJsonParser

pub struct LowLevelJsonParser { /* private fields */ }

A low-level JSON parser acting on a provided buffer.

Does not allocate except a stack to check if array and object opening and closing are properly nested. This stack size might be limited using the method with_max_stack_size.

use json_event_parser::{JsonEvent, LowLevelJsonParser, LowLevelJsonParserResult};

let mut reader = LowLevelJsonParser::new();
assert!(matches!(
    reader.parse_next(b"{\"foo".as_slice(), false),
    LowLevelJsonParserResult {
        consumed_bytes: 1,
        event: Some(Ok(JsonEvent::StartObject))
    }
));
assert!(matches!(
    reader.parse_next(b"\"foo".as_slice(), false),
    LowLevelJsonParserResult {
        consumed_bytes: 0,
        event: None
    }
));
assert!(matches!(
    reader.parse_next(b"\"foo\": 1}".as_slice(), false),
    LowLevelJsonParserResult {
        consumed_bytes: 5,
        event: Some(Ok(JsonEvent::ObjectKey(Cow::Borrowed("foo"))))
    }
));
assert!(matches!(
    reader.parse_next(b": 1}".as_slice(), false),
    LowLevelJsonParserResult {
        consumed_bytes: 3,
        event: Some(Ok(JsonEvent::Number(Cow::Borrowed("1"))))
    }
));
assert!(matches!(
    reader.parse_next(b"}".as_slice(), false),
    LowLevelJsonParserResult {
        consumed_bytes: 1,
        event: Some(Ok(JsonEvent::EndObject))
    }
));
assert!(matches!(
    reader.parse_next(b"".as_slice(), true),
    LowLevelJsonParserResult {
        consumed_bytes: 0,
        event: Some(Ok(JsonEvent::Eof))
    }
));

Implementations

impl LowLevelJsonParser

pub const fn new() -> Self

pub fn with_max_stack_size(self, size: usize) -> Self

Maximal allowed number of nested object and array openings. Infinite by default.

pub fn parse_next<'a>( &mut self, input_buffer: &'a [u8], is_ending: bool, ) -> LowLevelJsonParserResult<'a>

Reads a new event from the data in input_buffer.

is_ending must be set to true if all the JSON data have been already consumed or are in input_buffer.

pub fn read_next_event<'a>( &mut self, input_buffer: &'a [u8], is_ending: bool, ) -> LowLevelJsonParserResult<'a>

👎Deprecated: Use parse_next() instead

Trait Implementations

impl Default for LowLevelJsonParser

fn default() -> Self

Returns the “default value” for a type.