Struct JsonParser 

pub struct JsonParser { /* private fields */ }

JSON format parser for tool calls

Handles pure JSON formats for function calling:

• Single tool call: {“name”: “fn”, “arguments”: {…}}
• Multiple tool calls: [{“name”: “fn1”, “arguments”: {…}}, …]
• With parameters instead of arguments: {“name”: “fn”, “parameters”: {…}}

Implementations

impl JsonParser

pub fn new() -> Self

Create a new JSON parser

Trait Implementations

impl Default for JsonParser

fn default() -> Self

Returns the “default value” for a type.

impl ToolParser for JsonParser

fn parse_complete<'life0, 'life1, 'async_trait>( &'life0 self, text: &'life1 str, ) -> Pin<Box<dyn Future<Output = ParserResult<(String, Vec<ToolCall>)>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Parse complete tool calls from final output Returns (remaining_normal_text, tool_calls) tuple

fn parse_incremental<'life0, 'life1, 'life2, 'async_trait>( &'life0 mut self, chunk: &'life1 str, tools: &'life2 [Tool], ) -> Pin<Box<dyn Future<Output = ParserResult<StreamingParseResult>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Parse tool calls from model output (streaming) Parsers now maintain internal state, so self is mutable

fn has_tool_markers(&self, text: &str) -> bool

Check if text contains tool calls in this parser’s format

fn get_unstreamed_tool_args(&self) -> Option<Vec<ToolCallItem>>

Get unstreamed tool call arguments Returns tool call items for arguments that have been parsed but not yet streamed

fn reset(&mut self)

Reset the parser state for reuse across requests. This should clear all buffers and reset state to initial values.

fn as_token_parser(&self) -> Option<&dyn TokenToolParser>

Optionally expose a token-aware parser implementation. Default returns None, meaning the parser only supports text input.