Struct PartialJsonParser 

pub struct PartialJsonParser { /* private fields */ }

Incremental JSON parser that can handle partial/incomplete JSON.

Builds up a string token by token and attempts to parse at each step, returning the best partial result possible. This is designed for streaming LLM output where JSON arrives in small chunks and may be incomplete until the stream finishes.

Strategy

1. Accumulate tokens into an internal buffer.
2. On each push_and_parse, attempt to parse the buffer as complete JSON.
3. If that fails, try to repair the partial JSON by closing unclosed brackets/braces and truncating incomplete string values.
4. If repair yields valid JSON, return it; otherwise return PartialJsonError::Incomplete.

Example

let mut parser = PartialJsonParser::new();
// Simulating token-by-token LLM output
let _ = parser.push_and_parse(r#"{"name":"#); // Incomplete
let v = parser.push_and_parse(r#""Alice","age":30}"#); // Ok({"name":"Alice","age":30})

Implementations

impl PartialJsonParser

pub fn new() -> Self

Create a new, empty parser.

pub fn push_and_parse(&mut self, token: &str) -> Result<Value, PartialJsonError>

Push a new token and attempt to parse the accumulated buffer.

Returns Ok(value) if the buffer (after optional repair) yields valid JSON, or Err(PartialJsonError::Incomplete) if it does not yet form any parseable JSON.

pub fn finalize(self) -> Result<Value, PartialJsonError>

Get the final complete value.

Call this when the stream has ended. It first tries to parse the full buffer, then falls back to the repaired version.

pub fn buffer(&self) -> &str

Return a reference to the current buffer contents.

pub fn is_in_string(&self) -> bool

Whether the parser is currently inside a JSON string.

pub fn depth(&self) -> usize

Current nesting depth of brackets/braces.

Trait Implementations

impl Default for PartialJsonParser

fn default() -> Self

Returns the “default value” for a type.