Implementation:Ggml org Llama cpp Json Partial Header

Knowledge Sources	Ggml_org_Llama_cpp
Domains	JSON, Parsing
Last Updated	2026-02-15 00:00 GMT

Overview

Declares the interface for partial JSON parsing with healing support, enabling incomplete JSON from streaming model outputs to be completed and parsed.

Description

This header defines `common_healing_marker` containing a raw marker and a `json_dump_marker` for locating the healing point in serialized output, and `common_json` wrapping an `nlohmann::ordered_json` plus the healing marker. It exposes two overloads of `common_json_parse`: one taking a string and one taking iterators, both accepting a `healing_marker` string to control how partial JSON is completed. When a healing marker is provided, the parser completes the partial JSON by adding the marker and whatever is needed to close the JSON structure.

Usage

Use this header when handling streaming model outputs that produce incomplete JSON. It is used throughout the server and chat infrastructure to parse partial JSON from tool calls and structured outputs in OAI-compatible format.

Code Reference

Source Location

• Repository: Ggml_org_Llama_cpp
• File: common/json-partial.h
• Lines: 1-39

Signature

struct common_healing_marker {
    std::string marker;
    std::string json_dump_marker;
};

struct common_json {
    nlohmann::ordered_json json;
    common_healing_marker healing_marker;
};

bool common_json_parse(
    const std::string & input,
    const std::string & healing_marker,
    common_json & out);

bool common_json_parse(
    std::string::const_iterator & it,
    const std::string::const_iterator & end,
    const std::string & healing_marker,
    common_json & out);

Import

#include "json-partial.h"

I/O Contract

Inputs

Name	Type	Required	Description
input	const std::string &	Yes	JSON string to parse (may be incomplete)
healing_marker	const std::string &	Yes	Marker string for healing partial JSON; empty string disables healing
it	std::string::const_iterator &	Yes	Iterator to current position in the JSON string (advanced on success)
end	const std::string::const_iterator &	Yes	End iterator for the JSON string

Outputs

Name	Type	Description
return value	bool	True if parsing (with optional healing) succeeded
out	common_json &	Parsed JSON object with healing marker information
out.json	nlohmann::ordered_json	The parsed (and possibly healed) JSON value
out.healing_marker	common_healing_marker	Contains the marker and json_dump_marker for locating the healing point

Usage Examples

#include "json-partial.h"

// Parse a complete JSON string (no healing)
common_json result;
bool ok = common_json_parse("{\"key\": \"value\"}", "", result);
// ok == true, result.json == {"key": "value"}

// Parse a partial JSON string with healing
common_json partial_result;
bool healed = common_json_parse("{\"name\": \"Al", "foo", partial_result);
// healed == true, partial_result.json is a complete JSON object
// partial_result.healing_marker.json_dump_marker can locate the healing point

Related Pages

• Principle:Ggml_org_Llama_cpp_Partial_JSON_Healing