File syn_json_read.h¶

FileList > src > syntropic > util > syn_json_read.h

Minimal JSON reader — in-place, zero-alloc. More...

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_JsonReader JSON reader — token array + parse state.
struct	SYN_JsonToken Parsed JSON token — key + value + type.

Public Types¶

Type	Name
enum	SYN_JsonType JSON value types.

Public Functions¶

Type	Name
const SYN_JsonToken *	syn_json_find (const SYN_JsonReader * r, const char * key) Find a token by key name.
bool	syn_json_get_bool (const SYN_JsonReader * r, const char * key, bool * out) Get a boolean value by key.
bool	syn_json_get_int (const SYN_JsonReader * r, const char * key, int32_t * out) Get an integer value by key.
bool	syn_json_get_str (const SYN_JsonReader * r, const char * key, char * out, size_t out_sz) Get a string value by key.
SYN_JsonType	syn_json_get_type (const SYN_JsonReader * r, const char * key) Get the type of a value by key.
bool	syn_json_is_null (const SYN_JsonReader * r, const char * key) Check if a key exists and is null.
bool	syn_json_parse (SYN_JsonReader * r, char * json, size_t len) Parse a JSON string in-place.

Macros¶

Type	Name
define	SYN_JSON_MAX_TOKENS `32` Maximum number of parsed JSON tokens per document.

Detailed Description¶

Parses a JSON string in-place, providing token-based access. No dynamic memory, no callbacks — just walks through the buffer and lets you query values by key path.

** **

char json[] = "{\"ssid\":\"MyNet\",\"channel\":6,\"hidden\":false}";
SYN_JsonReader r;
syn_json_parse(&r, json, strlen(json));

char ssid[33];
if (syn_json_get_str(&r, "ssid", ssid, sizeof(ssid))) { ... }

int32_t ch;
if (syn_json_get_int(&r, "channel", &ch)) { ... }

bool hidden;
if (syn_json_get_bool(&r, "hidden", &hidden)) { ... }

** **

Top-level must be an object {}
Nested objects accessed via dot notation: "wifi.ssid"
No array indexing (arrays can be iterated)
Modifies the input buffer (inserts null terminators)
Max 32 tokens (keys + values) per parse

Public Types Documentation¶

enum SYN_JsonType¶

JSON value types.

enum SYN_JsonType {
    SYN_JSON_NONE = 0,
    SYN_JSON_STRING = 1,
    SYN_JSON_NUMBER = 2,
    SYN_JSON_BOOL = 3,
    SYN_JSON_NULL = 4,
    SYN_JSON_OBJECT = 5,
    SYN_JSON_ARRAY = 6
};

Public Functions Documentation¶

function syn_json_find¶

Find a token by key name.

const SYN_JsonToken * syn_json_find (
    const SYN_JsonReader * r,
    const char * key
)

Use dot notation for nested keys: "wifi.ssid"

Parameters:

r Reader.
key Key to find.

Returns:

Pointer to token, or NULL if not found.

function syn_json_get_bool¶

Get a boolean value by key.

bool syn_json_get_bool (
    const SYN_JsonReader * r,
    const char * key,
    bool * out
)

Parameters:

r Reader.
key Key to find.
out Output value.

Returns:

true if key found and value is a boolean.

function syn_json_get_int¶

Get an integer value by key.

bool syn_json_get_int (
    const SYN_JsonReader * r,
    const char * key,
    int32_t * out
)

Parameters:

r Reader.
key Key to find.
out Output value.

Returns:

true if key found and value is a number.

function syn_json_get_str¶

Get a string value by key.

bool syn_json_get_str (
    const SYN_JsonReader * r,
    const char * key,
    char * out,
    size_t out_sz
)

Parameters:

r Reader.
key Key to find.
out Output buffer for the string.
out_sz Buffer capacity.

Returns:

true if key found and value is a string.

function syn_json_get_type¶

Get the type of a value by key.

SYN_JsonType syn_json_get_type (
    const SYN_JsonReader * r,
    const char * key
)

Parameters:

r Reader.
key Key to find.

Returns:

SYN_JsonType, or SYN_JSON_NONE if not found.

function syn_json_is_null¶

Check if a key exists and is null.

bool syn_json_is_null (
    const SYN_JsonReader * r,
    const char * key
)

Parameters:

r Reader.
key Key to find.

Returns:

true if key exists and value is null.

function syn_json_parse¶

Parse a JSON string in-place.

bool syn_json_parse (
    SYN_JsonReader * r,
    char * json,
    size_t len
)

Tokenizes the JSON into key-value pairs. Modifies the input buffer (inserts null terminators at string boundaries).

Parameters:

r Reader instance.
json JSON string (will be modified).
len Length of JSON string.

Returns:

true if parsing succeeded.

Macro Definition Documentation¶

define SYN_JSON_MAX_TOKENS¶

Maximum number of parsed JSON tokens per document.

#define SYN_JSON_MAX_TOKENS `32`

The documentation for this class was generated from the following file src/syntropic/util/syn_json_read.h