File syn_json_read.c¶

FileList > src > syntropic > util > syn_json_read.c

Minimal JSON reader — in-place tokenizer.

#include "../util/syn_assert.h"
#include "syn_json_read.h"
#include <string.h>

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.

Public Static Functions¶

Type	Name
int32_t	parse_int (const char * s) Parse a signed integer from a string.
char *	parse_object (SYN_JsonReader * r, char * p, const char * end, uint8_t depth) Recursive JSON object parser.
char *	parse_string (char * p, const char * end, const char ** out) Parse a JSON string starting at p.
char *	skip_value (char * p, const char * end) Skip a JSON value (any type).
char *	skip_ws (char * p, const char * end) Skip whitespace.

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.

Public Static Functions Documentation¶

function parse_int¶

Parse a signed integer from a string.

static int32_t parse_int (
    const char * s
)

Parameters:

s Input string.

Returns:

Parsed value.

function parse_object¶

Recursive JSON object parser.

static char * parse_object (
    SYN_JsonReader * r,
    char * p,
    const char * end,
    uint8_t depth
)

Tokenizes key-value pairs at the given depth.

Parameters:

r JSON reader instance.
p Current position.
end End of buffer.
depth Current nesting depth.

Returns:

Pointer past the object.

function parse_string¶

Parse a JSON string starting at p.

static char * parse_string (
    char * p,
    const char * end,
    const char ** out
)

Must point to opening '"'. Null-terminates in-place.

Parameters:

p Current position (at opening '"').
end End of buffer.
out [out] Start of the string content.

Returns:

Pointer past the closing '"', or NULL on error.

function skip_value¶

Skip a JSON value (any type).

static char * skip_value (
    char * p,
    const char * end
)

Parameters:

p Current position.
end End of buffer.

Returns:

Pointer past the value.

function skip_ws¶

Skip whitespace.

static char * skip_ws (
    char * p,
    const char * end
)

Parameters:

p Current position.
end End of buffer.

Returns:

Pointer to next non-whitespace char.

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