json.c File Reference

json-c helpers for Fun VM JSON-related opcodes (conditional build). More...

#include <json-c/json.h>

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Functions
static Value	json_to_fun (json_object *j)
	Convert a json-c object tree into a Fun Value.
static json_object *	fun_to_json (const Value *v)
	Convert a Fun Value into a newly allocated json-c object tree.

Detailed Description

json-c helpers for Fun VM JSON-related opcodes (conditional build).

This module centralizes small utilities that convert between json-c objects and the Fun VM's Value type. Keeping the concrete conversion logic in src/extensions/ allows VM opcode implementations to remain minimal — they focus on VM stack marshalling and delegate the heavy lifting here, mirroring other extensions (PCRE2, SQLite, XML2, INI).

Build-time feature flag:

• All code in this file is compiled only when FUN_WITH_JSON is enabled. When disabled, JSON-related opcodes should provide safe no-op fallbacks in their respective VM files.

Type mapping between json-c and Fun:

• json null -> Fun Nil
• json boolean -> Fun Bool
• json number -> Fun Int (64-bit) or Fun Float (double) depending on the underlying json-c representation
• json string -> Fun String (assumed UTF-8 from json-c)
• json array -> Fun Array (elements converted recursively)
• json object -> Fun Map<string, any> (values converted recursively)

Ownership and memory:

• The conversion functions allocate new Fun Values and/or new json-c trees. The caller owns the returned result and is responsible for releasing it (free_value for Fun Values, json_object_put for json-c objects) when no longer needed.
• No global state is retained; all allocations are tied to the returned objects.

Encoding and limits:

• json-c strings are treated as UTF-8; the Fun VM strings are expected to be UTF-8 as well. No transcoding is performed.
• Deeply nested inputs convert recursively; extremely deep trees may exhaust the C stack. Cycles are not possible in well-formed JSON; if presented via custom json_object graphs, behaviour is undefined (may loop or duplicate).

Thread-safety:

• Not intrinsically thread-safe or unsafe. The helpers are stateless; each invocation operates on its arguments only. Coordinate external access to shared json_object instances if they are mutated concurrently.

Definition in file json.c.

Function Documentation

fun_to_json()

json_object * fun_to_json ( const Value * v )

static

Convert a Fun Value into a newly allocated json-c object tree.

Mapping rules:

• Nil -> json null
• Bool -> json boolean
• Int (64-bit) -> json int64
• Float (double) -> json double
• String -> json string (assumes UTF-8 already)
• Array -> json array (elements converted recursively)
• Map -> json object (keys are taken from the map's string keys)

Unsupported or opaque Fun types are stringified using the placeholder "<unsupported>" to keep the conversion total.

Ownership:

• The caller owns the returned json_object* and must release it with json_object_put() when no longer needed.

Notes and limitations:

• Map keys are enumerated via map_keys_array(); only string keys are used. Non-string keys are ignored.
• json-c does not support NaN/Inf as JSON numbers in a standard way; if such values appear in Fun Float, they are forwarded to json-c as-is.

Parameters

v	Pointer to the source Value (must not be NULL).

Returns

json_object* Newly created tree representing v.

Definition at line 159 of file json.c.

json_to_fun()

Value json_to_fun ( json_object * j )

static

Convert a json-c object tree into a Fun Value.

Mapping rules:

• null -> Nil
• boolean -> Bool
• number (int/double) -> Int/Float (uses json_object_get_int64/json_object_get_double)
• string -> String (assumes UTF-8, no transcoding)
• array -> Array (elements converted recursively, preserving order)
• object -> Map<string, any> (values converted recursively; keys are copied as-is)

Error handling and ownership:

• If j is NULL, returns Nil.
• The returned Value is newly created and owned by the caller, who must dispose it with free_value() when done. Internally allocated temporaries are released before returning.

Notes:

• json-c may store numbers as double even when they look integral; such values will end up as Float in Fun.
• Deep or large JSON inputs are traversed recursively; excessive depth could lead to stack pressure.

Parameters

j	Pointer to a json_object (may be NULL).

Returns

Value Converted Value (Nil on NULL input or on unsupported types).

Definition at line 88 of file json.c.