Enum that contains the following elements:
- JERRY_INIT_EMPTY - empty flag set
- JERRY_INIT_SHOW_OPCODES - dump byte-code to log after parse
- JERRY_INIT_SHOW_REGEXP_OPCODES - dump regexp byte-code to log after compilation
- JERRY_INIT_MEM_STATS - dump memory statistics
- JERRY_INIT_MEM_STATS_SEPARATE - dump memory statistics and reset peak values after parse
- JERRY_INIT_DEBUGGER - deprecated, an unused placeholder now
Enum that contains a set of elements to represent JavaScript type:
- JERRY_TYPE_NONE - no type information
- JERRY_TYPE_UNDEFINED - undefined value
- JERRY_TYPE_NULL - null value
- JERRY_TYPE_BOOLEAN - boolean value
- JERRY_TYPE_NUMBER - number value
- JERRY_TYPE_STRING - string value
- JERRY_TYPE_OBJECT - object value
- JERRY_TYPE_FUNCTION - function value
Possible types of an error:
- JERRY_ERROR_COMMON - common error
- JERRY_ERROR_EVAL - eval error
- JERRY_ERROR_RANGE - range error
- JERRY_ERROR_REFERENCE - reference error
- JERRY_ERROR_SYNTAX - syntax error
- JERRY_ERROR_TYPE - type error
- JERRY_ERROR_URI - URI error
There is also a special value JERRY_ERROR_NONE which is not an error type
this value can only be returned by the jerry_get_error_type.
Possible compile time enabled feature types:
- JERRY_FEATURE_CPOINTER_32_BIT - 32 bit compressed pointers
- JERRY_FEATURE_ERROR_MESSAGES - error messages
- JERRY_FEATURE_JS_PARSER - js-parser
- JERRY_FEATURE_MEM_STATS - memory statistics
- JERRY_FEATURE_PARSER_DUMP - parser byte-code dumps
- JERRY_FEATURE_REGEXP_DUMP - regexp byte-code dumps
- JERRY_FEATURE_SNAPSHOT_SAVE - saving snapshot files
- JERRY_FEATURE_SNAPSHOT_EXEC - executing snapshot files
- JERRY_FEATURE_DEBUGGER - debugging
- JERRY_FEATURE_VM_EXEC_STOP - stopping ECMAScript execution
Summary
Jerry's char value
Prototype
typedef uint8_t jerry_char_t;Summary
Pointer to an array of character values
Prototype
typedef jerry_char_t *jerry_char_ptr_t;Summary
Jerry's size
Prototype
typedef uint32_t jerry_size_t;Summary
Jerry's length
Prototype
typedef uint32_t jerry_length_t;Summary
JerryScript value can be a boolean, number, null, object, string or undefined. The value has an error flag, that indicates whether is an error or not. Every type has an error flag not only objects. The error flag should be cleared before the value is passed as an argument, otherwise it can lead to a type error. The error objects created by API functions has the error flag set.
Prototype
typedef uint32_t jerry_value_t;Summary
Structure that defines how a context data item will be initialized and deinitialized. JerryScript zeroes out the memory
for the item by default, and if the init_cb field is not NULL, it will be called with the pointer to the memory as
an additional custom initializer. The deinit_cb (if non-NULL) is called during a call to jerry_cleanup() to run
any custom deinitialization.
Prototype
typedef struct
{
void (*init_cb) (void *); /**< callback responsible for initializing a context item, or NULL */
void (*deinit_cb) (void *); /**< callback responsible for deinitializing a context item, or NULL */
size_t bytes_needed; /**< number of bytes to allocate for this manager */
} jerry_context_data_manager_t;Summary
Description of ECMA property descriptor
Prototype
typedef struct
{
/** Is [[Value]] defined? */
bool is_value_defined;
/** Is [[Get]] defined? */
bool is_get_defined;
/** Is [[Set]] defined? */
bool is_set_defined;
/** Is [[Writable]] defined? */
bool is_writable_defined;
/** [[Writable]] */
bool is_writable;
/** Is [[Enumerable]] defined? */
bool is_enumerable_defined;
/** [[Enumerable]] */
bool is_enumerable;
/** Is [[Configurable]] defined? */
bool is_configurable_defined;
/** [[Configurable]] */
bool is_configurable;
/** [[Value]] */
jerry_value_t value;
/** [[Get]] */
jerry_value_t getter;
/** [[Set]] */
jerry_value_t setter;
} jerry_property_descriptor_t;summary
Description of JerryScript heap memory stats. It is for memory profiling.
Prototype
typedef struct
{
size_t version /**< the version of the stats struct */
size_t size; /**< heap total size */
size_t allocated_bytes; /**< currently allocated bytes */
size_t peak_allocated_bytes; /**< peak allocated bytes */
size_t reserved[4]; /**< padding for future extensions */
} jerry_heap_stats_t;Summary
Type of an external function handler
Prototype
typedef jerry_value_t (*jerry_external_handler_t) (const jerry_value_t function_obj,
const jerry_value_t this_val,
const jerry_value_t args_p[],
const jerry_length_t args_count);Summary
Deprecated: Please use jerry_object_native_free_callback_t instead.
Native free callback of an object.
Prototype
typedef void (*jerry_object_free_callback_t) (const uintptr_t native_p);Summary
Native free callback of an object. It is used in jerry_object_native_info_t.
Prototype
typedef void (*jerry_object_native_free_callback_t) (void *native_p);Summary
The type infomation of the native pointer. It includes the free callback that will be called when associated JavaScript object is garbage collected. It can be left NULL in case it is not needed.
Typically, one would create a static const jerry_object_native_info_t for
each distinct C type for which a pointer is used with
jerry_set_object_native_pointer () and jerry_get_object_native_pointer ().
This way, each const jerry_object_native_info_t * pointer address value itself
uniquely identifies the C type of the native pointer.
See jerry_get_object_native_pointer for a best-practice code example.
Prototype
typedef struct
{
jerry_object_native_free_callback_t free_cb;
} jerry_object_native_info_t;See also
Summary
Function type applied for each data property of an object
Prototype
typedef bool (*jerry_object_property_foreach_t) (const jerry_value_t property_name,
const jerry_value_t property_value,
void *user_data_p);Summary
Callback which tells whether the ECMAScript execution should be stopped. If it returns with undefined value the ECMAScript execution continues. Otherwise the result is thrown by the engine (if the error flag is not set for the returned value the engine automatically sets it). The callback function might be called again even if it threw an error. In this case the function must throw the same error again.
Prototype
typedef jerry_value_t (*jerry_vm_exec_stop_callback_t) (void *user_p);See also
Enum which describes the TypedArray types. Possible values:
- JERRY_TYPEDARRAY_UINT8 - represents the Uint8Array TypedArray
- JERRY_TYPEDARRAY_UINT8CLAMPED - represents the Uint8ClampedArray TypedArray
- JERRY_TYPEDARRAY_INT8 - represents the Int8Array TypedArray
- JERRY_TYPEDARRAY_UINT16 - represents the Uint16Array TypedArray
- JERRY_TYPEDARRAY_INT16 - represents the Int16Array TypedArray
- JERRY_TYPEDARRAY_UINT32 - represents the Uint32Array TypedArray
- JERRY_TYPEDARRAY_INT32 - represents the Int32Array TypedArray
- JERRY_TYPEDARRAY_FLOAT32 - represents the Float32Array TypedArray
- JERRY_TYPEDARRAY_FLOAT64 - represents the Float64Array TypedArray
- JERRY_TYPEDARRAY_INVALID - represents an invalid TypedArray
API functions can return the JERRY_TYPEDARRAY_INVALID value if the
TypedArray support is not in the engine.
Summary
Initializes the JerryScript engine, making it possible to run JavaScript code and perform operations on JavaScript values.
Prototype
void
jerry_init (jerry_init_flag_t flags)flags - combination of various engine configuration flags:
JERRY_INIT_EMPTY- no flags, just initialize in default configuration.JERRY_INIT_SHOW_OPCODES- print compiled byte-code.JERRY_INIT_SHOW_REGEXP_OPCODES- print compiled regexp byte-code.JERRY_INIT_MEM_STATS- dump memory statistics.JERRY_INIT_MEM_STATS_SEPARATE- dump memory statistics and reset peak values after parse.JERRY_INIT_DEBUGGER- deprecated, an unused placeholder now
Example
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_SHOW_OPCODES | JERRY_INIT_SHOW_REGEXP_OPCODES);
// ...
jerry_cleanup ();
}See also
Summary
Finish JavaScript engine execution, freeing memory and JavaScript values.
Note: JavaScript values, received from engine, will be inaccessible after the cleanup.
Prototype
void
jerry_cleanup (void);See also
Summary
Retrieve a pointer to the item stored within the current context by the given manager.
Note: Since internally the pointer to a manager's context data item is linked to the next such pointer in a linked list, it is inadvisable to invoke too many different managers, because doing so will increase the time it takes to retrieve a manager's context data item, degrading performance. For example, try to keep the number of managers below five.
Prototype
void *
jerry_get_context_data (const jerry_context_data_manager *manager_p);manager_p: the manager of this context data item.- return value: the item created by
manager_pwhenjerry_get_context_data ()was first called, or a new item created bymanager_p, which will be stored for future identical calls tojerry_get_context_data (), and which will be deinitialized using thedeinit_cbcallback provided bymanager_pwhen the context will be destroyed.
Example
#include "jerryscript.h"
typedef struct
{
int my_data1;
double my_data2;
char *my_data3;
} my_context_data_t;
/* Define how context items will be initialized. */
static void
my_context_data_new (void *user_data_p)
{
my_context_data_t *my_data_p = (my_context_data_t *) user_data_p;
/*
* Initialize my_data_p. JerryScript will store it on the current context and return it whenever
* jerry_get_context_data () is called with a pointer to my_manager as defined below.
*/
}
/* Define how context items will be deinitialized */
static void
my_context_data_free (void *user_data_p)
{
my_context_data_t *my_data_p = ((my_context_data_t *) user_data_p);
/* Perform any necessary cleanup on my_data. JerryScript will free the pointer after this function completes. */
}
/* Wrap the creation and destruction functions into a manager */
static const jerry_context_data_manager_t my_manager =
{
.init_cb = my_context_data_new,
.deinit_cb = my_context_data_free,
.bytes_needed = sizeof (my_context_data_t)
};
/*
* Then, in some function in your code, you can retrieve an item of type my_context_data_t from the currently active
* context such that JerryScript will create and store such an item if one was not previously created
*/
static void
someplace_in_the_code (void)
{
my_context_data_t *my_data = (my_context_data_t *) jerry_get_context_data (&my_manager);
/* Perform useful things using the data found in my_data */
}Summary
Registers an external magic string array.
Note: The strings in the array must be sorted by size at first, then lexicographically.
Prototype
void
jerry_register_magic_strings (const jerry_char_ptr_t *ex_str_items_p,
uint32_t count,
const jerry_length_t *str_lengths_p);ex_str_items_p- character arrays, representing external magic strings' contentscount- number of the stringsstr_lengths_p- lengths of the strings
Example
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
// must be static, because 'jerry_register_magic_strings' does not copy
// the items must be sorted by size at first, then lexicographically
static const jerry_char_ptr_t magic_string_items[] = {
(const jerry_char_ptr_t) "magicstring1",
(const jerry_char_ptr_t) "magicstring2",
(const jerry_char_ptr_t) "magicstring3"
};
uint32_t num_magic_string_items = (uint32_t) (sizeof (magic_string_items) / sizeof (jerry_char_ptr_t));
// must be static, because 'jerry_register_magic_strings' does not copy
static const jerry_length_t magic_string_lengths[] = {
12,
12,
12
};
jerry_register_magic_strings (magic_string_items, num_magic_string_items, magic_string_lengths);
}See also
Summary
Gets configured memory limits of JerryScript.
Prototype
void
jerry_get_memory_limits (size_t *out_data_bss_brk_limit_p,
size_t *out_stack_limit_p);out_data_bss_brk_limit_p- out parameter, that gives the maximum size of data + bss + brk sections.out_stack_limit_p- out parameter, that gives the maximum size of the stack.
Example
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
size_t stack_limit;
size_t data_bss_brk_limit;
jerry_get_memory_limits (&stack_limit, &data_bss_brk_limit);
}See also
Summary
Get heap memory stats.
Prototype
bool
jerry_get_memory_stats (jerry_heap_stats_t *out_stats_p);out_stats_p- out parameter, that provides the heap statistics.- return value
- true, if run was successful
- false, otherwise. Usually it is because the MEM_STATS feature is not enabled.
Example
jerry_heap_stats_t stats = {0};
bool get_stats_ret = jerry_get_memory_stats (&stats);See also
Summary
Performs garbage collection.
Prototype
void
jerry_gc (void);Example
jerry_gc ();See also
Functions to parse and run JavaScript source code.
Summary
The simplest way to run JavaScript.
Prototype
bool
jerry_run_simple (const jerry_char_t *script_source_p,
size_t script_source_size,
jerry_init_flag_t flags);script_source_p- source code, it must be a valid utf8 string.script_source_size- size of source code buffer, in bytes.jerry_init_flag_t- combination of various engine configuration flags- return value
- true, if run was successful
- false, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
const jerry_char_t *script = (const jerry_char_t *) "print ('Hello, World!');";
jerry_run_simple (script, strlen ((const char *) script), JERRY_INIT_EMPTY);
}See also
Summary
Parse script and construct an EcmaScript function. The lexical environment is set to the global lexical environment.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_parse (const jerry_char_t *source_p,
size_t source_size,
bool is_strict);source_p- string, containing source code to parse (must be a valid UTF8 string).source_size- size of the string, in bytes.is_strict- defines strict mode.- return value
- function object value, if script was parsed successfully,
- thrown error, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
const jerry_char_t script[] = "print ('Hello, World!');";
size_t script_size = strlen ((const char *) script);
jerry_value_t parsed_code = jerry_parse (script, script_size, false);
jerry_release_value (parsed_code);
jerry_cleanup ();
}See also
Summary
Parse script and construct an ECMAScript function. The lexical environment is set to the global lexical environment. The resource name (usually a file name) is also passed to this function which is used by the debugger to find the source code.
Note: The returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_parse_named_resource (const jerry_char_t *resource_name_p, /**< resource name (usually a file name) */
size_t resource_name_length, /**< length of resource name */
const jerry_char_t *source_p, /**< script source */
size_t source_size, /**< script source size */
bool is_strict) /**< strict mode */resource_name_p- resource name, usually a file name (must be a valid UTF8 string).resource_name_length- size of the resource name, in bytes.source_p- string, containing source code to parse (must be a valid UTF8 string).source_size- size of the string, in bytes.is_strict- defines strict mode.- return value
- function object value, if script was parsed successfully,
- thrown error, otherwise
This function is identical to jerry_parse, except that an additional filename parameter has been added.
Summary
Parse function source code and construct an ECMAScript function. The function arguments and function body are passed as separated arguments. The lexical environment is set to the global lexical environment. The resource name (usually a file name) is also passed to this function which is used by the debugger to find the source code.
Note: The returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_parse_function (const jerry_char_t *resource_name_p, /**< resource name (usually a file name) */
size_t resource_name_length, /**< length of resource name */
const jerry_char_t *arg_list_p, /**< script source */
size_t arg_list_size, /**< script source size */
const jerry_char_t *source_p, /**< script source */
size_t source_size, /**< script source size */
bool is_strict) /**< strict mode */resource_name_p- resource name, usually a file name (must be a valid UTF8 string).resource_name_length- size of the resource name, in bytes.arg_list_p- argument list of the function (must be a valid UTF8 string).arg_list_size- size of the argument list, in bytes.source_p- string, containing source code to parse (must be a valid UTF8 string).source_size- size of the string, in bytes.is_strict- defines strict mode.- return value
- function object value, if script was parsed successfully,
- thrown error, otherwise
Summary
Run an EcmaScript function created by jerry_parse.
Note: The code should be previously parsed with jerry_parse.
Prototype
jerry_value_t
jerry_run (const jerry_value_t func_val);func_val- function to run- return value
- result of bytecode, if run was successful
- thrown error, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
const jerry_char_t script[] = "print ('Hello, World!');";
size_t script_size = strlen ((const char *) script);
/* Initialize engine */
jerry_init (JERRY_INIT_EMPTY);
/* Setup Global scope code */
jerry_value_t parsed_code = jerry_parse (script, script_size, false);
if (!jerry_value_has_error_flag (parsed_code))
{
/* Execute the parsed source code in the Global scope */
jerry_value_t ret_value = jerry_run (parsed_code);
/* Returned value must be freed */
jerry_release_value (ret_value);
}
/* Parsed source code must be freed */
jerry_release_value (parsed_code);
/* Cleanup engine */
jerry_cleanup ();
}See also
Summary
Perform JavaScript eval.
Prototype
jerry_value_t
jerry_eval (const jerry_char_t *source_p,
size_t source_size,
bool is_strict);source_p- source code to evaluate, it must be a valid utf8 string.source_size- length of the source codeis_strict- performevalas it is called from "strict mode" code.- return value - result of eval, may be error value.
Example
{
jerry_value_t ret_val = jerry_eval (str_to_eval,
strlen (str_to_eval),
false);
}See also
Summary
Run enqueued Promise jobs until the first thrown error or until all get executed.
Prototype
jerry_value_t
jerry_run_all_enqueued_jobs (void)- return value - result of last executed job, may be error value.
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
const jerry_char_t script[] = "new Promise(function(f,r) { f('Hello, World!'); }).then(function(x) { print(x); });";
size_t script_size = strlen ((const char *) script);
jerry_value_t parsed_code = jerry_parse (script, script_size, false);
jerry_value_t script_value = jerry_run (parsed_code);
jerry_value_t job_value = jerry_run_all_enqueued_jobs ();
jerry_release_value (job_value);
jerry_release_value (script_value);
jerry_release_value (parsed_code);
jerry_cleanup ();
}Summary
Get the Global object.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_get_global_object (void);- return value - api value of global object
Example
{
jerry_value_t glob_obj_val = jerry_get_global_object ();
... // Do something with global object, ex: add properties
jerry_release_value (glob_obj_val);
}See also
Functions to check the type of an API value (jerry_value_t).
Summary
Returns whether the given jerry_value_t is an array.
Prototype
bool
jerry_value_is_array (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis an array - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_array (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is an ArrayBuffer object.
Prototype
bool
jerry_value_is_arraybuffer (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis an ArrayBuffer object. - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_arraybuffer (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a boolean value.
Prototype
bool
jerry_value_is_boolean (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a boolean value - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_boolean (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a constructor function.
Prototype
bool
jerry_value_is_constructor (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a constructor - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_constructor (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a function.
Prototype
bool
jerry_value_is_function (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a function - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_function (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a number.
Prototype
bool
jerry_value_is_function (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a number - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_number (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a null value.
Prototype
bool
jerry_value_is_null (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a null - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_null (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is an object value.
Prototype
bool
jerry_value_is_object (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis an object - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_object (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a promise value.
Note: This API depends on the ES2015-subset profile.
Prototype
bool
jerry_value_is_promise (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a promise - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_promise (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is a string value.
Prototype
bool
jerry_value_is_string (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis a string - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_string (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Checks whether the given jerry_value_t is a TypedArray object or not.
Prototype
bool
jerry_value_is_typedarray (const jerry_value_t value)value- object to check- return value
- true, if the given
jerry_value_tis a TypedArray object. - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_typedarray (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t is an undefined value.
Prototype
bool
jerry_value_is_undefined (const jerry_value_t value)value- api value- return value
- true, if the given
jerry_value_tis an undefined value - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_undefined (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns the JavaScript type for a given value as a jerry_type_t enum value.
This is a similar operation as the 'typeof' operator in the standard with an exception that the 'null' value has its own enum value.
Prototype
jerry_type_t
jerry_value_get_type (const jerry_value_t value);Example
{
jerry_value_t number = jerry_create_number (3.3);
jerry_type_t type_info = jerry_value_get_type (number);
if (type_info == JERRY_TYPE_NUMBER)
{
...
}
jerry_value_release (number);
}See also
Summary
Returns whether the specified compile time feature is enabled.
Prototype
bool
jerry_is_feature_enabled (const jerry_feature_t feature);feature- jerry feature- return value
- true, if the given
jerry_feature_tis enabled - false, otherwise
- true, if the given
Example
{
...
jerry_feature_t feature = JERRY_FEATURE_SNAPSHOT_SAVE;
if (jerry_is_feature_enabled (feature))
{
...
}
}Summary
Returns the type of the Error object if possible.
If a non-error object is used as the input for the function the method
will return JERRY_ERROR_NONE indicating that the value was not
an Error object. However it is still possible that the value contains
error semantics. To correctly detect if a value have error use the
jerry_value_has_error_flag method.
Prototype
jerry_error_t
jerry_get_error_type (const jerry_value_t value);value- api value (possible error object)- return value
- JERRY_ERROR_NONE if the input is not an error object
- one of the jerry_error_t value
Example
{
jerry_value_t error_obj = jerry_create_error (JERRY_ERROR_RANGE,
(const jerry_char_t *) "error msg");
jerry_error_t error_type = jerry_get_error_type (error_obj);
// error_type is now JERRY_ERROR_RANGE.
jerry_release_value (error_obj);
}See also
Summary
Returns whether the given jerry_value_t has the error flag set.
Prototype
bool
jerry_value_has_error_flag (const jerry_value_t value);value- api value- return value
- true, if the given
jerry_value_thas the error flag set - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_has_error_flag (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Returns whether the given jerry_value_t has the error and abort flags set.
Prototype
bool
jerry_value_has_abort_flag (const jerry_value_t value);value- api value- return value
- true, if the given
jerry_value_thas the error and abort flags set - false, otherwise
- true, if the given
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_has_abort_flag (value))
{
...
}
jerry_release_value (value);
}See also
Summary
Clear both the error and abort flags.
Prototype
void
jerry_value_clear_error_flag (jerry_value_t *value_p);value_p- pointer to an api value
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_clear_error_flag (&value);
jerry_release_value (value);
}See also
Summary
Set the error flag.
Prototype
void
jerry_value_set_error_flag (jerry_value_t *value_p);value_p- pointer to an api value
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_set_error_flag (&value);
jerry_release_value (value);
}See also
Summary
Set both the error and abort flags.
Prototype
void
jerry_value_set_abort_flag (jerry_value_t *value_p);value_p- pointer to an api value
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_set_abort_flag (&value);
jerry_release_value (value);
}See also
Summary
If the input value is an error value, then return a new reference to its referenced value. Otherwise, return a new reference to the value itself.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_get_value_without_error_flag (jerry_value_t value)value- api value
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_set_error_flag (&value);
jerry_value_t real_value = jerry_get_value_without_error_flag (value);
... // process the real_value. Different from `jerry_value_clear_error_flag`,
// the error `value` will not be automatically released after calling
// `jerry_get_value_without_error_flag`.
jerry_release_value (value);
jerry_release_value (real_value);
}See also
Get raw data from API values.
Summary
Gets the raw bool value from a jerry_value_t.
Prototype
bool
jerry_get_boolean_value (const jerry_value_t value);value- api value- return value - boolean value represented by the argument.
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_boolean (value))
{
bool raw_value = jerry_get_boolean_value (value);
... // usage of raw value
}
jerry_release_value (value);
}See also
Summary
Gets the number value of the given jerry_value_t parameter as a raw double.
Prototype
double
jerry_get_number_value (const jerry_value_t value);value- api value- return value - the number value of the given
jerry_value_tparameter as a raw double.
Example
{
jerry_value_t value;
... // create or acquire value
if (jerry_value_is_number (value))
{
double raw_value = jerry_get_number_value (value);
... // usage of raw value
}
jerry_release_value (value);
}See also
Summary
Get the size of a string. Returns zero, if the value parameter is not a string.
Prototype
jerry_size_t
jerry_get_string_size (const jerry_value_t value);value- api value- return value - number of bytes in the buffer needed to represent the string.
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string = jerry_create_string (char_array);
jerry_size_t string_size = jerry_get_string_size (string);
... // usage of string_size
jerry_release_value (string);
}See also
Summary
Get the size of an utf8-encoded string. Returns zero, if the value parameter is not a string.
Note: The difference from jerry_get_string_size is that it returns with utf-8 string size instead of the cesu-8 string size.
Prototype
jerry_size_t
jerry_get_utf8_string_size (const jerry_value_t value);value- api value- return value - number of bytes in the buffer needed to represent the utf8-encoded string.
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string = jerry_create_string (char_array);
jerry_size_t string_size = jerry_get_utf8_string_size (string);
... // usage of string_size
jerry_release_value (string);
}See also
Summary
Get the length of a string. Returns zero, if the value parameter is not a string.
Prototype
jerry_length_t
jerry_get_string_length (const jerry_value_t value);value- api value- return value - number of characters in the string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string = jerry_create_string (char_array);
jerry_length_t string_length = jerry_get_string_length (string);
... // usage of string_length
jerry_release_value (string);
}See also
Summary
Get the length of an UTF-8 encoded string. Returns zero, if the value parameter is not a string.
Note: The difference from jerry_get_string_length is that it returns with utf-8 string length instead of the cesu-8 string length.
Prototype
jerry_length_t
jerry_get_utf8_string_length (const jerry_value_t value);value- input string value- return value - number of characters in the string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string = jerry_create_string_from_utf8 (char_array);
jerry_length_t string_length = jerry_get_utf8_string_length (string);
... // usage of string_length
jerry_release_value (string);
}See also
Summary
Copy the characters of a string into a specified cesu-8 buffer. The '\0' character could occur in the character buffer. Returns 0, if the value parameter is not a string or the buffer is not large enough for the whole string.
Note: Does not put '\0' to the end of string, the return value identifies the number of valid bytes in the output buffer.
Note: If the size of the string in jerry value is larger than the size of the target buffer, the copy will fail. To copy a substring the jerry_substring_to_char_buffer API function is recommended instead.
Prototype
jerry_size_t
jerry_string_to_char_buffer (const jerry_value_t value,
jerry_char_t *buffer_p,
jerry_size_t buffer_size);value- input string valuebuffer_p- pointer to output bufferbuffer_size- size of the buffer- return value - number of bytes, actually copied to the buffer
Example
{
jerry_value_t value;
... // create or acquire value
jerry_size_t req_sz = jerry_get_string_size (value);
jerry_char_t str_buf_p[req_sz];
jerry_string_to_char_buffer (value, str_buf_p, req_sz);
jerry_release_value (value);
}See also
- jerry_create_string
- jerry_get_string_size
- jerry_is_valid_cesu8_string
- jerry_substring_to_char_buffer
Summary
Copy the characters of a string into a specified utf-8 buffer. The '\0' character could occur in character buffer. Returns 0, if the value parameter is not a string or the buffer is not large enough for the whole string.
Note: Does not put '\0' to the end of string, the return value identifies the number of valid bytes in the output buffer.
Note: If the size of the string in jerry value is larger than the size of the target buffer, the copy will fail. To copy a substring the jerry_substring_to_utf8_char_buffer API function is recommended instead.
Prototype
jerry_size_t
jerry_string_to_utf8_char_buffer (const jerry_value_t value,
jerry_char_t *buffer_p,
jerry_size_t buffer_size);value- input string valuebuffer_p- pointer to output bufferbuffer_size- size of the buffer- return value - number of bytes, actually copied to the buffer
Example
{
jerry_value_t value;
... // create or acquire value
jerry_size_t req_sz = jerry_get_utf8_string_size (value);
jerry_char_t str_buf_p[req_sz];
jerry_string_to_utf8_char_buffer (value, str_buf_p, req_sz);
jerry_release_value (value);
}See also
- jerry_create_string_from_utf8
- jerry_get_utf8_string_size
- jerry_is_valid_utf8_string
- jerry_substring_to_utf8_char_buffer
Summary
Copy the characters of a cesu-8 encoded substring into a specified buffer. The '\0' character could occur in character buffer. Returns 0, if the value parameter is not a string. It will extract the substring between the specified start position and the end position (or the end of the string, whichever comes first).
Note: Does not put '\0' to the end of string, the return value identifies the number of valid bytes in the output buffer.
Prototype
jerry_size_t
jerry_substring_to_char_buffer (const jerry_value_t value,
jerry_length_t start_pos,
jerry_length_t end_pos,
jerry_char_t *buffer_p,
jerry_size_t buffer_size);value- input string valuestart_pos- position of the first characterend_pos- position of the last characterbuffer_p- pointer to output bufferbuffer_size- size of the buffer- return value - number of bytes, actually copied to the buffer
Example
{
jerry_value_t value;
... // create or acquire value
jerry_size_t req_sz = jerry_get_string_size (value);
jerry_char_t str_buf_p[req_sz];
jerry_length_t start_pos = 0;
jerry_length_t end_pos = jerry_get_string_length (value);
jerry_substring_to_char_buffer (value, start_pos, end_pos, str_buf_p, req_sz);
jerry_release_value (value);
}See also
Summary
Copy the characters of an utf-8 encoded substring into a specified buffer. The '\0' character could occur in character buffer. Returns 0, if the value parameter is not a string. It will extract the substring between the specified start position and the end position (or the end of the string, whichever comes first).
Note: Does not put '\0' to the end of string, the return value identifies the number of valid bytes in the output buffer.
Prototype
jerry_size_t
jerry_substring_to_utf8_char_buffer (const jerry_value_t value,
jerry_length_t start_pos,
jerry_length_t end_pos,
jerry_char_t *buffer_p,
jerry_size_t buffer_size);value- input string valuestart_pos- position of the first characterend_pos- position of the last characterbuffer_p- pointer to output bufferbuffer_size- size of the buffer- return value - number of bytes, actually copied to the buffer
Example
{
jerry_value_t value;
... // create or acquire value
jerry_size_t req_sz = jerry_get_utf8_string_size (value);
jerry_char_t str_buf_p[req_sz];
jerry_length_t start_pos = 0;
jerry_length_t end_pos = jerry_get_utf8_string_length (value);
jerry_substring_to_utf8_char_buffer (value, start_pos, end_pos, str_buf_p, req_sz);
jerry_release_value (value);
}See also
- jerry_create_string_from_utf8
- jerry_get_utf8_string_size
- jerry_get_utf8_string_length
- jerry_is_valid_utf8_string
Summary
Get length of an array object. Returns zero, if the given parameter is not an array object.
Prototype
uint32_t
jerry_get_array_length (const jerry_value_t value);value- input array value- return value - length of the given array
Example
{
jerry_value_t value;
... // create or acquire value
uint32_t len = jerry_get_array_length (value);
jerry_release_value (value);
}See also
Functions for converting API values to another value type.
Summary
Call ToBoolean operation on the api value.
Prototype
bool
jerry_value_to_boolean (const jerry_value_t value);value- api value- return value
- true, if the logical value is true
- false, otherwise
Example
{
jerry_value_t value;
... // create or acquire value
bool b = jerry_value_to_boolean (value);
jerry_release_value (value);
}See also
Summary
Call ToNumber operation on the api value.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_value_to_number (const jerry_value_t value);value- api value- return value
- converted number value, if success
- thrown error, otherwise
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_t number_value = jerry_value_to_number (value);
jerry_release_value (number_value);
jerry_release_value (value);
}See also
Summary
Call ToObject operation on the api value.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_value_to_object (const jerry_value_t value);value- api value- return value
- converted object value, if success
- thrown error, otherwise
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_t object_value = jerry_value_to_object (value);
jerry_release_value (object_value);
jerry_release_value (value);
}See also
Summary
Call ToPrimitive operation on the api value.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_value_to_primitive (const jerry_value_t value);value- api value- return value
- converted primitive value, if success
- thrown error, otherwise
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_t prim_value = jerry_value_to_primitive (value);
jerry_release_value (prim_value);
jerry_release_value (value);
}See also
Summary
Call the ToString ecma builtin operation on the api value.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_value_to_string (const jerry_value_t value);value- api value- return value
- converted string value, if success
- thrown error, otherwise
Example
{
jerry_value_t value;
... // create or acquire value
jerry_value_t string_value = jerry_value_to_string (value);
jerry_release_value (string_value);
jerry_release_value (value);
}See also
These APIs all depends on the ES2015-subset profile.
Summary
Resolve or reject the promise with an argument.
Prototype
jerry_value_t
jerry_resolve_or_reject_promise (jerry_value_t promise,
jerry_value_t argument,
bool is_resolve)promise- the promise valueargument- the argument for resolve or rejectis_resolve- whether the promise should be resolved or rejected- return value
- undefined jerry value - resolve or reject successed
- jerry value with error flag - otherwise
Example
{
jerry_value_t promise = ... // acquire/create a promise object.
...
bool is_resolve = ... // whether the promise should be resolved or rejected
jerry_value_t argument = ... // prepare the argumnent for the resolve or reject.
jerry_value_t is_ok = jerry_resolve_or_reject_promise (promise,
argument,
is_resolve);
if (jerry_value_has_error_flag (is_ok))
{
// handle the error.
}
jerry_release_value (is_ok);
jerry_release_value (argument);
jerry_release_value (promise);
}See also
Summary
Acquires the specified Jerry API value.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_acquire_value (jerry_value_t value);value- api value- return value - acquired value that may be used outside of the engine
Example
{
jerry_value_t object_value = jerry_create_object ();
jerry_value_t acquired_object = jerry_acquire_value (object_value);
jerry_release_value (object_value);
// acquired_object refers to the created object and makes it
// available after the release of 'object_value'
jerry_release_value (acquired_object);
}See also
Summary
Release specified Jerry API value.
Prototype
void
jerry_release_value (jerry_value_t value);value- api value
Example
{
jerry_value_t object_value = jerry_create_object ();
...
jerry_release_value (object_value);
}Function for creating API values.
Note: Every created API value must be freed with jerry_release_value when it is no longer needed.
Summary
Create an array object value.
Prototype
jerry_value_t
jerry_create_array (uint32_t size);size- size of array;- return value - value of the constructed array object
Example
{
jerry_value_t array = jerry_create_array (10);
...
jerry_release_value (array);
}See also
Summary
Create a jerry_value_t representing an ArrayBuffer object.
Prototype
jerry_value_t
jerry_create_arraybuffer (jerry_length_t size);size- size of the ArrayBuffer to create in bytes- return value - the new ArrayBuffer as a
jerry_value_t
Example
{
jerry_value_t buffer_value = jerry_create_arraybuffer (15);
... // use the ArrayBuffer
jerry_release_value (buffer_value);
}See also
Summary
Creates a jerry_value_t representing an ArrayBuffer object with user specified back-buffer.
User must pass a buffer pointer which is at least size big.
After the object is not needed the GC will call the free_cb
so the user can release the buffer which was provided.
Prototype
jerry_value_t
jerry_create_arraybuffer_external (const jerry_length_t size
uint8_t *buffer_p,
jerry_object_native_free_callback_t free_cb);size- size of the buffer to use in bytes (should not be 0)buffer_p- the buffer used for the Array Buffer object (should not be a null pointer)free_cb- the callback function called when the object is released- return value
- the new ArrayBuffer as a
jerry_value_t - if the
sizeis zero orbuffer_pis a null pointer will return RangeError
- the new ArrayBuffer as a
Example
{
uint8_t buffer_p[15];
jerry_value_t buffer_value = jerry_create_arraybuffer_external (15, buffer_p, NULL);
... // use the array buffer
jerry_release_value (buffer_value);
}See also
- jerry_get_arraybuffer_pointer
- jerry_arraybuffer_read
- jerry_arraybuffer_write
- jerry_value_is_arraybuffer
- jerry_release_value
- jerry_object_native_free_callback_t
Summary
Create a jerry_value_t representing a boolean value from the given boolean parameter.
Prototype
jerry_value_t
jerry_create_boolean (bool value);value- raw boolean value.- return value - a
jerry_value_tcreated from the given boolean argument.
Example
{
jerry_value_t boolean_value = jerry_create_boolean (true);
... // usage of the value
jerry_release_value (boolean_value);
}See also
Summary
Create new JavaScript error object.
Important! The error_type argument must not be
JERRY_ERROR_NONE.
Creating an error with no error type is not valid.
Prototype
jerry_value_t
jerry_create_error (jerry_error_t error_type,
const jerry_char_t *message_p);error_type- type of errormessage_p- value of 'message' property of constructed error object- return value - value of the constructed error object
Example
{
jerry_value_t error_obj = jerry_create_error (JERRY_ERROR_TYPE,
(const jerry_char_t *) "error");
... // usage of error_obj
jerry_release_value (error_obj);
}See also
Summary
Create new JavaScript error object.
Prototype
jerry_value_t
jerry_create_error_sz (jerry_error_t error_type,
const jerry_char_t *message_p,
jerry_size_t message_size);error_type- type of the errormessage_p- value of 'message' property of the constructed error objectmessage_size- size of the message in bytes- return value - value of the constructed error object
Example
{
const jerry_char_t *message = "error";
jerry_value_t error_obj = jerry_create_error_sz (JERRY_ERROR_COMMON,
message,
strlen ((const char *) message));
... // usage of error_obj
jerry_release_value (error_obj);
}See also
Summary
Create an external function object.
Prototype
jerry_value_t
jerry_create_external_function (jerry_external_handler_t handler_p);handler_p- pointer to native handler of the function object- return value - value of the constructed function object
Example
static jerry_value_t
handler (const jerry_value_t function_obj,
const jerry_value_t this_val,
const jerry_value_t args_p[],
const jerry_length_t args_cnt)
{
printf ("native handler called!\n");
return jerry_create_boolean (true);
}
{
jerry_value_t func_val = jerry_create_external_function (handler);
jerry_value_t glob_obj = jerry_get_global_object ();
// after this, script can invoke the native handler through "handler_field (1, 2, 3);"
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "handler_field");
// set property and release the return value without any check
jerry_release_value (jerry_set_property (glob_obj, prop_name, func_val));
jerry_release_value (prop_name);
jerry_release_value (func_val);
jerry_release_value (glob_obj);
}See also
Summary
Creates a jerry_value_t representing a number value.
Prototype
jerry_value_t
jerry_create_number (double value);value- double value from which ajerry_value_twill be created- return value - a
jerry_value_tcreated from the given double argument
Example
{
jerry_value_t number_value = jerry_create_number (3.14);
... // usage of the value
jerry_release_value (number_value);
}See also
Summary
Creates a jerry_value_t representing a positive or negative infinity value.
Prototype
jerry_value_t
jerry_create_number_infinity (bool sign);sign- true for negative Infinity and false for positive Infinity- return value - a
jerry_value_trepresenting the infinity value
Example
{
jerry_value_t positive_inf_value = jerry_create_number_infinity (false);
... // usage of the positive_inf_value
jerry_release_value (positive_inf_value);
}See also
Summary
Creates a jerry_value_t representing a not-a-number value.
Prototype
jerry_value_t
jerry_create_number_nan (void);- return value - a
jerry_value_trepresenting the not-a-number value
Example
{
jerry_value_t nan_value = jerry_create_number_nan ();
... // usage of the nan_value
jerry_release_value (nan_value);
}See also
Summary
Creates and returns a jerry_value_t with type null object.
Prototype
jerry_value_t
jerry_create_null (void);- return value - a
jerry_value_trepresenting null.
Example
{
jerry_value_t null_value = jerry_create_null ();
... // usage of the value
jerry_release_value (null_value);
}See also
Summary
Create new JavaScript object, like with new Object().
Prototype
jerry_value_t
jerry_create_object (void);- return value - value of the created object
Example
{
jerry_value_t object_value = jerry_create_object ();
... // usage of object_value
jerry_release_value (object_value);
}See also
Summary
Create an empty promise object which can be resolved or rejected later by calling jerry_resolve_or_reject_promise.
Note: This API depends on the ES2015-subset profile.
Prototype
jerry_value_t
jerry_create_promise (void)- return value - value of the newly created promise
Example
{
jerry_value_t p = jerry_create_promise ();
...// usage of the promise
jerry_release_value (p);
}See also
Summary
Create string from a valid CESU8 string.
Prototype
jerry_value_t
jerry_create_string (const jerry_char_t *str_p);str_p- pointer to string- return value - value of the created string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string_value = jerry_create_string (char_array);
... // usage of string_value
jerry_release_value (string_value);
}See also
Summary
Create string from a valid CESU8 string.
Prototype
jerry_value_t
jerry_create_string_sz (const jerry_char_t *str_p,
jerry_size_t str_size)str_p- pointer to stringstr_size- size of the string- return value - value of the created string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string_value = jerry_create_string_sz (char_array,
strlen ((const char *) char_array));
... // usage of string_value
jerry_release_value (string_value);
}See also
Summary
Create string from a valid UTF8 string.
Note: The difference from jerry_create_string is that it accepts utf-8 string instead of cesu-8 string.
Prototype
jerry_value_t
jerry_create_string_from_utf8 (const jerry_char_t *str_p);str_p- pointer to string- return value - value of the created string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string_value = jerry_create_string_from_utf8 (char_array);
... // usage of string_value
jerry_release_value (string_value);
}See also
Summary
Create string from a valid UTF8 string.
Note: The difference from jerry_create_string_sz is that it accepts utf-8 string instead of cesu-8 string.
Prototype
jerry_value_t
jerry_create_string_sz (const jerry_char_t *str_p,
jerry_size_t str_size)str_p- pointer to stringstr_size- size of the string- return value - value of the created string
Example
{
const jerry_char_t char_array[] = "a string";
jerry_value_t string_value = jerry_create_string_sz_from_utf8 (char_array,
strlen ((const char *) char_array));
... // usage of string_value
jerry_release_value (string_value);
}See also
Summary
Create a jerry_value_t representing an TypedArray object.
For the new object the type of the TypedArray (see: jerry_typedarray_type_t) and element count can be specified.
Prototype
jerry_value_t
jerry_create_typedarray (jerry_typedarray_type_t type_name, jerry_length_t item_count);type_name- type of TypedArray to createitem_count- number of items in the new TypedArray- return value - the new TypedArray as a
jerry_value_t
Example
{
jerry_value_t array = jerry_create_typedarray (JERRY_TYPEDARRAY_UINT16, 15);
... // use the TypedArray
jerry_release_value (array);
}See also
Summary
Create a jerry_value_t representing an TypedArray object using an already existing ArrayBuffer object.
For the new object the type of the TypedArray (see: jerry_typedarray_type_t) and element count can be specified.
The developer must ensure that the ArrayBuffer has the correct length for the given type of TypedArray otherwise an error is generated.
The JavaScript equivalent of this function is: new %TypedArray%(arraybuffer) where %TypedArray% is
one of the allowed TypedArray functions.
Prototype
jerry_value_t
jerry_create_typedarray_for_arraybuffer (jerry_typedarray_type_t type_name,
const jerry_value_t arraybuffer);type_name- type of TypedArray to createarraybuffer- the ArrayBuffer to use for the new TypedArray- return value
- the new TypedArray as a
jerry_value_t - Error if the ArrayBuffer does not have enough space for the given type of TypedArray
- the new TypedArray as a
Example
{
jerry_value_t buffer = jerry_create_array_buffer (12 * 2);
jerry_value_t array = jerry_create_typedarray_for_arraybuffer (JERRY_TYPEDARRAY_UINT16, buffer);
jerry_release_value (buffer);
... // use the TypedArray
jerry_release_value (array);
}See also
Summary
Create a jerry_value_t representing an TypedArray object using an already existing ArrayBuffer object and by specifying the byteOffset, and length properties.
For the new object the type of the TypedArray (see: jerry_typedarray_type_t) and element count can be specified.
The developer must ensure that the ArrayBuffer has the correct length for the given type of TypedArray otherwise an error is generated.
The JavaScript equivalent of this function is: new %TypedArray%(arraybuffer, byteOffset, length) where %TypedArray% is
one of the allowed TypedArray functions.
Prototype
jerry_value_t
jerry_create_typedarray_for_arraybuffer_sz (jerry_typedarray_type_t type_name,
const jerry_value_t arraybuffer,
jerry_length_t byte_offset,
jerry_length_t length);type_name- type of TypedArray to createarraybuffer- the ArrayBuffer to use for the new TypedArraybyte_offset- start offset to use for the ArrayBufferlength- number of elements to used from the ArrayBuffer (this is not the same as the byteLength)- return value
- the new TypedArray as a
jerry_value_t - Error if the ArrayBuffer does not have enough space for the given type of TypedArray
- the new TypedArray as a
Example
{
jerry_value_t buffer = jerry_create_array_buffer (12 * 2);
jerry_value_t array = jerry_create_typedarray_for_arraybuffer_sz (JERRY_TYPEDARRAY_UINT16, buffer, 4, 10);
jerry_release_value (buffer);
... // use the TypedArray
jerry_release_value (array);
}See also
Summary
Creates a jerry_value_t representing an undefined value.
Prototype
jerry_value_t
jerry_create_undefined (void);- return value - value of undefined
Example
{
jerry_value_t undefined_value = jerry_create_undefined ();
... // usage of the value
jerry_release_value (undefined_value);
}See also
Summary
Checks whether the object or its prototype objects have the given property.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_has_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val);obj_val- object valueprop_name_val- property name- return value - JavaScript boolean value that evaluates to
- true, if the property exists
- false, otherwise
Example
{
jerry_value_t global_object = jerry_get_global_object ();
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "handler_field");
jerry_value_t has_prop_js = jerry_has_property (global_object, prop_name);
bool has_prop = jerry_get_boolean_value (has_prop_js);
jerry_release_value (has_prop_js);
jerry_release_value (prop_name);
jerry_release_value (global_object);
}See also
Summary
Checks whether the object has the given property.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_has_own_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val);obj_val- object valueprop_name_val- property name- return value - JavaScript boolean value that evaluates to
- true, if the property exists
- false, otherwise
Example
{
jerry_value_t global_object = jerry_get_global_object ();
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "handler_field");
jerry_value_t has_prop_js = jerry_has_own_property (global_object, prop_name);
bool has_prop = jerry_get_boolean_value (has_prop_js);
jerry_release_value (jas_prop_js);
jerry_release_value (prop_name);
jerry_release_value (global_object);
}See also
Summary
Delete a property from an object.
Prototype
bool
jerry_delete_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val);obj_val- object valueprop_name_val- property name- return value
- true, if property was deleted successfully
- false, otherwise
Example
{
jerry_value_t global_object = jerry_get_global_object ();
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "my_prop");
jerry_delete_property (global_object, prop_name);
jerry_release_value (prop_name);
jerry_release_value (global_object);
}See also
Summary
Delete indexed property from the specified object.
Prototype
bool
jerry_delete_property_by_index (const jerry_value_t obj_val,
uint32_t index);obj_val- object valueindex- index number- return value
- true, if property was deleted successfully
- false, otherwise
Example
{
jerry_value_t object;
... // create or acquire object
jerry_delete_property_by_index (object, 5);
jerry_release_value (object);
}See also
- jerry_has_property
- jerry_has_own_property
- jerry_delete_property
- jerry_get_property
- jerry_set_property
- jerry_get_property_by_index
- jerry_set_property_by_index
Summary
Get value of a property to the specified object with the given name.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_get_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val);obj_val- object valueprop_name_val- property name- return value
- value of property, if success
- thrown error, otherwise
Example
{
jerry_value_t global_object = jerry_get_global_object ();
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "my_prop");
jerry_value_t prop_value = jerry_get_property (obj_val, prop_name);
jerry_release_value (prop_name);
jerry_release_value (global_object);
}See also
- jerry_has_property
- jerry_has_own_property
- jerry_delete_property
- jerry_delete_property_by_index
- jerry_set_property
- jerry_get_property_by_index
- jerry_set_property_by_index
Summary
Get value by an index from the specified object.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_get_property_by_index (const jerry_value_t obj_val,
uint32_t index);obj_val- object valueindex- index number- return value
- stored value on the specified index, if success
- thrown exception, otherwise.
Example
{
jerry_value_t object;
... // create or acquire object
jerry_value_t value = jerry_get_property_by_index (object, 5);
...
jerry_release_value (value);
jerry_release_value (object);
}See also
- jerry_has_property
- jerry_has_own_property
- jerry_delete_property
- jerry_delete_property_by_index
- jerry_get_property
- jerry_set_property
- jerry_set_property_by_index
Summary
Set a property to the specified object with the given name.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_set_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val,
const jerry_value_t value_to_set)obj_val- object valueprop_name_val- property namevalue_to_set- value to set- return value
- true, if success
- thrown error, otherwise
Example
{
jerry_value_t value_to_set;
... // create or acquire value to set
jerry_value_t glob_obj = jerry_get_global_object ();
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "my_prop");
jerry_value_t set_result = jerry_set_property (glob_obj, prop_name, value_to_set);
... // check result of property set call
jerry_release_value (set_result);
jerry_release_value (prop_name);
...
jerry_release_value (value_to_set);
jerry_release_value (glob_obj);
}See also
- jerry_has_property
- jerry_has_own_property
- jerry_delete_property
- jerry_delete_property_by_index
- jerry_get_property
- jerry_get_property_by_index
- jerry_set_property_by_index
Summary
Set indexed value in the specified object
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_set_property_by_index (const jerry_value_t obj_val,
uint32_t index,
const jerry_value_t value_to_set);obj_val- object valueindex- index numbervalue_to_set- value to set- return value
- true, if field value was set successfully
- thrown exception, otherwise
Example
{
jerry_value_t object;
jerry_value_t value_to_set;
... // create or acquire object and value to set
jerry_value_t ret_val = jerry_set_property_by_index (object, 5, value_to_set);
...
jerry_release_value (value_to_set);
jerry_release_value (ret_val);
jerry_release_value (object);
}See also
- jerry_has_property
- jerry_has_own_property
- jerry_delete_property
- jerry_delete_property_by_index
- jerry_get_property
- jerry_set_property
- jerry_get_property_by_index
Summary
Initialize property descriptor.
Prototype
void
jerry_init_property_descriptor_fields (jerry_property_descriptor_t *prop_desc_p);prop_desc_p- pointer to property descriptor
Example
{
jerry_property_descriptor_t prop_desc;
jerry_init_property_descriptor_fields (&prop_desc);
... // usage of prop_desc
jerry_free_property_descriptor_fields (&prop_desc);
}See also
Summary
Define a property to the specified object with the given name.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_define_own_property (const jerry_value_t obj_val,
const jerry_value_t prop_name_val,
const jerry_property_descriptor_t *prop_desc_p);obj_val- object valueprop_name_val- property nameprop_desc_p- pointer to property descriptor- return value
- true, if success
- thrown error, otherwise
Example
{
jerry_value_t global_obj_val = jerry_get_global_object ();
jerry_property_descriptor_t prop_desc;
jerry_init_property_descriptor_fields (&prop_desc);
jerry_value_t value_to_set;
... // create or acquire value to set
prop_desc.is_value_defined = true;
prop_desc.value = value_to_set;
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "my_prop");
jerry_value_t return_value = jerry_define_own_property (global_obj_val, prop_name, &prop_desc);
jerry_release_value (return_value);
jerry_release_value (prop_name);
jerry_free_property_descriptor_fields (&prop_desc);
jerry_release_value (global_obj_val);
}See also
- jerry_init_property_descriptor_fields
- jerry_get_own_property_descriptor
- jerry_free_property_descriptor_fields
Summary
Construct property descriptor from specified property.
Prototype
bool
jerry_get_own_property_descriptor (const jerry_value_t obj_val,
const jerry_value_t prop_name_val,
jerry_property_descriptor_t *prop_desc_p);obj_val- object valueprop_name_val- property nameprop_desc_p- pointer to property descriptor- return value
Example
{
jerry_value_t global_obj_val = jerry_get_global_object ();
jerry_property_descriptor_t prop_desc;
jerry_init_property_descriptor_fields (&prop_desc);
jerry_value_t prop_name = jerry_create_string ((const jerry_char_t *) "my_prop");
jerry_get_own_property_descriptor (global_obj_val, prop_name, &prop_desc);
jerry_release_value (prop_name);
... // usage of property descriptor
jerry_free_property_descriptor_fields (&prop_desc);
jerry_release_value (global_obj_val);
}See also
- jerry_init_property_descriptor_fields
- jerry_define_own_property
- jerry_free_property_descriptor_fields
Summary
Free fields of property descriptor (setter, getter and value).
Prototype
void
jerry_free_property_descriptor_fields (const jerry_property_descriptor_t *prop_desc_p);prop_desc_p- pointer to property descriptor
Example
{
jerry_property_descriptor_t prop_desc;
jerry_init_property_descriptor_fields (&prop_desc);
... // usage of property descriptor
jerry_free_property_descriptor_fields (&prop_desc);
}See also
Summary
Call function specified by a function value. Error flag must
not be set for any arguments of this function. Value of this
parameter should be set to undefined for non-method calls.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_call_function (const jerry_value_t func_obj_val,
const jerry_value_t this_val,
const jerry_value_t args_p[],
jerry_size_t args_count);func_obj_val- the function object to callthis_val- object for 'this' bindingargs_p- function's call argumentsargs_count- number of arguments- return value - returned jerry value of the called function
Example
{
jerry_value_t val;
... // receiving val
if (jerry_value_is_function (val))
{
jerry_value_t this_val = jerry_create_undefined ();
jerry_value_t ret_val = jerry_call_function (val, this_val, NULL, 0);
if (!jerry_value_has_error_flag (ret_val))
{
... // handle return value
}
jerry_release_value (ret_val);
jerry_release_value (this_val);
}
jerry_release_value (val);
}See also
Summary
Construct object, invoking specified function object as constructor. Error flag must not be set for any arguments of this function.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_construct_object (const jerry_value_t func_obj_val,
const jerry_value_t args_p[],
jerry_size_t args_count);func_obj_val- function object to callargs_p- function's call argumentsargs_count- number of arguments- return value - returned value of the invoked constructor
Example
{
jerry_value_t val;
... // receiving val
if (jerry_is_constructor (val))
{
jerry_value_t ret_val = jerry_construct_object (val, NULL, 0);
if (!jerry_value_has_error_flag (ret_val))
{
... // handle return value
}
jerry_release_value (ret_val);
}
}See also
Summary
Get keys of the specified object value.
Prototype
jerry_value_t
jerry_get_object_keys (const jerry_value_t obj_val);obj_val- object value- return value
- array object value, if success
- thrown error, otherwise
Example
{
jerry_value_t object;
... // create or acquire object
jerry_value_t keys_array = jerry_get_object_keys (object);
... // usage of keys_array
jerry_release_value (keys_array);
}See also
Summary
Get the prototype of the specified object.
Prototype
jerry_value_t
jerry_get_prototype (const jerry_value_t obj_val);obj_val- object value- return value
- object value, if success
- null or thrown error, otherwise
Example
{
jerry_value_t object;
... // create or acquire object
jerry_value_t prototype = jerry_get_prototype (object);
... // usage of prototype object
jerry_release_value (prototype);
jerry_release_value (object);
}See also
Summary
Set the prototype of the specified object.
Prototype
jerry_value_t
jerry_set_prototype (const jerry_value_t obj_val,
const jerry_value_t proto_obj_val);obj_val- object valueproto_obj_val- prototype object value- return value
- true, if success
- thrown error, otherwise
Example
{
jerry_value_t object;
jerry_value_t prototype;
... // create or acquire object and prototype
jerry_value_t ret_val = jerry_set_prototype (object, prototype);
jerry_release_value (ret_val);
jerry_release_value (prototype);
jerry_release_value (object);
}See also
Summary
Deprecated: Please use jerry_get_object_native_pointer instead.
Get native handle, previously associated with specified object.
Prototype
bool
jerry_get_object_native_handle (const jerry_value_t obj_val,
uintptr_t *out_handle_p);obj_val- object valueout_handle_p- handle value (output parameter).- return value
- true, if there is handle associated with the object
- false, otherwise
Example
{
jerry_value_t object;
uintptr_t handle_set;
... // receive or construct object and handle_set value
jerry_set_object_native_handle (object, handle_set, NULL);
...
uintptr_t handle_get;
bool is_there_associated_handle = jerry_get_object_native_handle (object, &handle_get);
}See also
Summary
Deprecated: Please use jerry_set_object_native_pointer instead.
Set native handle and an optional free callback for the specified object.
Note: If native handle was already set for the object, its value is updated.
Note: If a non-NULL free callback is specified, it will be called by the garbage collector when the object is freed. The free callback always overwrites the previous value, so passing a NULL value deletes the current free callback.
Prototype
void
jerry_set_object_native_handle (const jerry_value_t obj_val,
uintptr_t handle_p,
jerry_object_free_callback_t freecb_p);obj_val- object value to set handle inhandle_p- handle valuefreecb_p- pointer to "free" callback or NULL
Example
{
jerry_value_t object;
uintptr_t handle_set;
... // receive or construct object and handle_set value
jerry_set_object_native_handle (object, handle_set, NULL);
...
uintptr_t handle_get;
bool is_there_associated_handle = jerry_get_object_native_handle (object, &handle_get);
}See also
Summary
Get native pointer and its type information. The pointer and the type information are previously associated with the object by jerry_set_object_native_pointer.
Note: It is recommended to ensure that the out_native_info_p value pointer
is equal to the native info pointer that is expected, before casting
and accessing the out_native_pointer_p.
An example of when this is important: external functions that expect
this to have a native pointer of a certain C type.
It is possible in JavaScript to change this at will – using call(),
apply() or bind(). Therefore, it is possible that the native pointer
of this is not of the expected C type. To handle this safely and
securely, one must always add type checks to make sure that the
out_native_pointer_p is of the expected type, before casting
and dereferencing out_native_pointer_p.
Note: out_native_pointer_p and out_native_info_p can be NULL, and it means the
caller doesn't want to get the native_pointer or type infomation.
Prototype
bool
jerry_get_object_native_pointer (const jerry_value_t obj_val,
void **out_native_pointer_p,
const jerry_object_native_info_t **out_native_info_p)obj_val- object value to get native pointer from.out_native_pointer_p- native pointer (output parameter).out_native_info_p- native pointer's type infomation (output parameter).- return value
- true, if there is native pointer associated with the object
- false, otherwise
Example
typedef struct {
int foo;
bool bar;
} native_obj_t;
static void native_freecb (void *native_p)
{
... // free the native pointer
}
// NOTE: The address (!) of type_info acts as a way to uniquely "identify" the
// C type `native_obj_t *`.
static const jerry_object_native_info_t native_obj_type_info =
{
.free_cb = native_freecb
};
// Function creating JS object that is "backed" by a native_obj_t *:
{
...
// construct object and native_set value:
jerry_value_t object = ...;
native_obj_t *native_obj = malloc(sizeof(*native_obj));
jerry_set_object_native_pointer (object, native_obj, &native_obj_type_info);
...
}
// Native method, `this` is expected to be "backed" by a native_obj_t *:
{
void *native_p;
const jerry_object_native_info_t *type_p;
bool has_p = jerry_get_object_native_pointer (this_val, &native_p, &type_p);
if (has_p)
{
// The type_p pointer address itself is used to identify the type:
if (type_p == &native_obj_type_info)
{
// The type of this's native pointer matches what is expected.
// Only now is it safe to cast to native_obj_t * and dereference the
// pointer:
native_obj_t *native_obj = native_p;
native_obj->bar = ...; // Safe to access now!
}
else
{
// The type of this's native pointer is NOT what we expected!
// We should not cast to native_obj_t * and dereference because it's unsafe.
// Handle the error here, for example throw an error.
}
}
...
}See also
Summary
Set native pointer and an optional type information for the specified object. You can get them by calling jerry_get_object_native_pointer later.
Note: If native pointer was already set for the object, its value is updated.
Note: If a non-NULL free callback is specified in the native type information, it will be called by the garbage collector when the object is freed. The type info is always overwrites the previous value, so passing a NULL value deletes the current type info.
Prototype
bool
jerry_set_object_native_pointer (const jerry_value_t obj_val,
void *native_p,
const jerry_object_native_info_t *info_p)obj_val- object to set native pointer in.native_p- native pointer.info_p- native pointer's type infomation or NULL. When used, this should be a long-lived pointer, usually a pointer to astatic const jerry_object_native_info_tmakes most sense.
Example
See jerry_get_object_native_pointer for a best-practice example.
See also
Summary
Applies the given function to every property in the given object.
Prototype
bool
jerry_foreach_object_property (jerry_value_t obj_val,
jerry_object_property_foreach_t foreach_p,
void *user_data_p);obj_val- object valueforeach_p- foreach function, that will be applied for each propertyuser_data_p- user data for foreach function- return value
- true, if object fields traversal was performed successfully, i.e.:
- no unhandled exceptions were thrown in object fields traversal
- object fields traversal was stopped on callback that returned false
- false, otherwise
- true, if object fields traversal was performed successfully, i.e.:
Example
bool foreach_function (const jerry_value_t prop_name,
const jerry_value_t prop_value,
void *user_data_p)
{
... // implementation of the foreach function
}
{
jerry_value_t object;
... // receive or construct object
double data = 3.14; // example data
jerry_foreach_object_property (object, foreach_function, &data);
}See also
Summary
Validate UTF-8 string.
Prototype
bool
jerry_is_valid_utf8_string (const jerry_char_t *utf8_buf_p, /**< UTF-8 string */
jerry_size_t buf_size) /**< string size */utf8_buf_p- UTF-8 input stringbuf_size- input string size
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
const jerry_char_t script[] = "print ('Hello, World!');";
size_t script_size = strlen ((const char *) script);
if (jerry_is_valid_utf8_string (script, (jerry_size_t) script_size))
{
jerry_run_simple (script, script_size, JERRY_INIT_EMPTY);
}
}See also
- jerry_run_simple
- jerry_create_string_from_utf8
- jerry_create_string_sz_from_utf8
- jerry_get_utf8_string_size
- jerry_get_utf8_string_length
- jerry_string_to_utf8_char_buffer
- jerry_substring_to_utf8_char_buffer
Summary
Validate CESU-8 string.
Prototype
bool
jerry_is_valid_cesu8_string (const jerry_char_t *cesu8_buf_p, /**< CESU-8 string */
jerry_size_t buf_size) /**< string size */cesu8_buf_p- CESU-8 input stringbuf_size- input string size
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
const jerry_char_t script[] = "Hello, World!";
size_t script_size = strlen ((const char *) script);
if (jerry_is_valid_cesu8_string (script, (jerry_size_t) script_size))
{
jerry_value_t string_value = jerry_create_string_sz (script,
(jerry_size_t) script_size);
// usage of string_value
jerry_release_value (string_value);
}
jerry_cleanup ();
}See also
- jerry_create_string
- jerry_create_string_sz
- jerry_get_string_size
- jerry_get_string_length
- jerry_string_to_char_buffer
- jerry_substring_to_char_buffer
Summary
Generate snapshot from the specified source code.
Prototype
size_t
jerry_parse_and_save_snapshot (const jerry_char_t *source_p,
size_t source_size,
bool is_for_global,
bool is_strict,
uint32_t *buffer_p,
size_t buffer_size);source_p- script source, it must be a valid utf8 string.source_size- script source size, in bytes.is_for_global- snapshot would be executed as global (true) or eval (false).is_strict- strict modebuffer_p- buffer to save snapshot to.buffer_size- the buffer's size.- return value
- the size of snapshot, if it was generated succesfully (i.e. there are no syntax errors in source code, buffer size is sufficient, and snapshot support is enabled in current configuration through JERRY_ENABLE_SNAPSHOT_SAVE)
- 0 otherwise.
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
static uint32_t global_mode_snapshot_buffer[256];
const jerry_char_t *code_to_snapshot_p = (const jerry_char_t *) "(function () { return 'string from snapshot'; }) ();";
size_t global_mode_snapshot_size = jerry_parse_and_save_snapshot (code_to_snapshot_p,
strlen ((const char *) code_to_snapshot_p),
true,
false,
global_mode_snapshot_buffer,
sizeof (global_mode_snapshot_buffer) / sizeof (uint32_t));
jerry_cleanup ();
}See also
Summary
Generate function snapshot from the specified source code with the given arguments.
The function arguments and function body are passed as separated arguments.
Prototype
size_t
jerry_parse_and_save_function_snapshot (const jerry_char_t *source_p,
size_t source_size,
const jerry_char_t *args_p,
size_t args_size,
bool is_strict,
uint32_t *buffer_p,
size_t buffer_size)source_p- script source, it must be a valid utf8 string.source_size- script source size, in bytes.args_p- function arguments, it must be a valid utf8 string.args_size- function argument size, in bytes.is_strict- strict modebuffer_p- buffer to save snapshot to.buffer_size- the buffer's size.- return value
- the size of snapshot, if it was generated succesfully (i.e. there are no syntax errors in source code, buffer size is sufficient, and snapshot support is enabled in current configuration through JERRY_ENABLE_SNAPSHOT_SAVE)
- 0 otherwise.
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
static uint32_t func_snapshot_buffer[256];
const jerry_char_t *args_p = (const jerry_char_t *) "a, b";
const jerry_char_t *src_p = (const jerry_char_t *) "return a + b;";
size_t func_snapshot_size = jerry_parse_and_save_function_snapshot (src_p,
strlen ((const char *) src_p),
args_p,
strlen ((const char *) args_p),
false,
func_snapshot_buffer,
sizeof (func_snapshot_buffer) / sizeof (uint32_t));
jerry_cleanup ();
}See also
Summary
Execute snapshot from the specified buffer.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_exec_snapshot (const uint32_t *snapshot_p,
size_t snapshot_size,
bool copy_bytecode);snapshot_p- pointer to snapshotsnapshot_size- size of snapshotcopy_bytecode- flag, indicating whether the passed snapshot buffer should be copied to the engine's memory. If set the engine should not reference the buffer after the function returns (in this case, the passed buffer could be freed after the call). Otherwise (if the flag is not set) - the buffer could only be freed after the engine stops (i.e. after call to jerry_cleanup).- return value
- result of bytecode, if run was successful
- thrown error, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
static uint32_t global_mode_snapshot_buffer[256];
const jerry_char_t *code_to_snapshot_p = (const jerry_char_t *) "(function () { return 'string from snapshot'; }) ();";
jerry_init (JERRY_INIT_EMPTY);
size_t global_mode_snapshot_size = jerry_parse_and_save_snapshot (code_to_snapshot_p,
strlen ((const char *) code_to_snapshot_p),
true,
false,
global_mode_snapshot_buffer,
sizeof (global_mode_snapshot_buffer) / sizeof (uint32_t));
jerry_cleanup ();
jerry_init (JERRY_INIT_EMPTY);
jerry_value_t res = jerry_exec_snapshot (global_mode_snapshot_buffer,
global_mode_snapshot_size,
false);
jerry_release_value (res);
jerry_cleanup ();
}See also
Summary
Execute the selected snapshot function from the specified buffer.
Same function as jerry_exec_snapshot except the executed function index can be specified.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_exec_snapshot_at (const uint32_t *snapshot_p,
size_t snapshot_size,
size_t func_index,
bool copy_bytecode);snapshot_p- pointer to snapshotsnapshot_size- size of snapshotfunc_index- index of executed functioncopy_bytecode- flag, indicating whether the passed snapshot buffer should be copied to the engine's memory. If set the engine should not reference the buffer after the function returns (in this case, the passed buffer could be freed after the call). Otherwise (if the flag is not set) - the buffer could only be freed after the engine stops (i.e. after call to jerry_cleanup).- return value
- result of bytecode, if run was successful
- thrown error, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
static uint32_t global_mode_snapshot_buffer[256];
const jerry_char_t *code_to_snapshot_p = (const jerry_char_t *) "(function () { return 'string from snapshot'; }) ();";
jerry_init (JERRY_INIT_EMPTY);
size_t global_mode_snapshot_size = jerry_parse_and_save_snapshot (code_to_snapshot_p,
strlen ((const char *) code_to_snapshot_p),
true,
false,
global_mode_snapshot_buffer,
sizeof (global_mode_snapshot_buffer) / sizeof (uint32_t));
jerry_cleanup ();
jerry_init (JERRY_INIT_EMPTY);
jerry_value_t res = jerry_exec_snapshot_at (global_mode_snapshot_buffer,
global_mode_snapshot_size,
0,
false);
jerry_release_value (res);
jerry_cleanup ();
return 0;
}See also
Summary
Load the selected snapshot function from the specified buffer as a function object.
The lexical environment of the loaded function is always the global lexical environment.
Note: Returned value must be freed with jerry_release_value when it is no longer needed.
Prototype
jerry_value_t
jerry_load_function_snapshot_at (const uint32_t *snapshot_p,
size_t snapshot_size,
size_t func_index,
bool copy_bytecode);snapshot_p- pointer to snapshotsnapshot_size- size of snapshotfunc_index- index of function to loadcopy_bytecode- flag, indicating whether the passed snapshot buffer should be copied to the engine's memory. If set the engine should not reference the buffer after the function returns (in this case, the passed buffer could be freed after the call). Otherwise (if the flag is not set) - the buffer could only be freed after the engine stops (i.e. after call to jerry_cleanup).- return value
- function object built from the snapshot
- thrown error, otherwise
Example
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
static uint32_t snapshot_buffer[256];
const jerry_char_t *args_p = (const jerry_char_t *)"a, b";
const jerry_char_t *src_p = (const jerry_char_t *) "return a + b;";
jerry_init (JERRY_INIT_EMPTY);
size_t snapshot_size = jerry_parse_and_save_function_snapshot (src_p,
strlen ((const char *) src_p),
args_p,
strlen ((const char *) args_p),
false,
snapshot_buffer,
sizeof (snapshot_buffer) / sizeof (uint32_t));
jerry_cleanup ();
jerry_init (JERRY_INIT_EMPTY);
jerry_value_t func = jerry_load_function_snapshot_at (snapshot_buffer,
snapshot_size,
0,
false);
/* 'func' can be used now as a function object */
jerry_value_t this_value = jerry_create_undefined ();
jerry_value_t args[2];
args[0] = jerry_create_number (1.0);
args[1] = jerry_create_number (2.0);
jerry_value_t res = jerry_call_function (func, this_value, args, 2);
/* 'res' now contains the value 3 as a jerry_value_t */
jerry_release_value (args[0]);
jerry_release_value (args[1]);
jerry_release_value (this_value);
jerry_release_value (func);
jerry_cleanup ();
return 0;
}See also
Summary
Collect the used literals from the given source code and save them into a specific file in a list or C format. These literals are generated by the parser, they are valid identifiers and none of them are magic string.
Prototype
size_t
jerry_parse_and_save_literals (const jerry_char_t *source_p,
size_t source_size,
bool is_strict,
uint32_t *buffer_p,
size_t buffer_size,
bool is_c_format);source_p- script source, it must be a valid utf8 string.source_size- script source size, in bytes.is_strict- strict mode.buffer_p- buffer to save literals to.buffer_size- the buffer's size.is_c_format- the output format would be C-style (true) or a simple list (false).- return value
- the size of the literal-list, if it was generated succesfully (i.e. the list of literals isn't empty, and literal-save support is enabled in current configuration through JERRY_ENABLE_SNAPSHOT_SAVE)
- 0 otherwise.
Example
#include <stdio.h>
#include <string.h>
#include "jerryscript.h"
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
static uint32_t save_literal_buffer[256];
const jerry_char_t *code_for_literal_save_p = (const jerry_char_t *) "var obj = { a:'aa', bb:'Bb' }";
size_t literal_sizes = jerry_parse_and_save_literals (code_for_literal_save_p,
strlen ((const char *) code_for_literal_save_p),
false,
save_literal_buffer,
sizeof (save_literal_buffer) / sizeof (uint32_t),
true);
if (literal_sizes != 0)
{
FILE *literal_file_p = fopen ("literals.txt", "w");
fwrite (save_literal_buffer, sizeof (uint8_t), literal_sizes, literal_file_p);
fclose (literal_file_p);
}
jerry_cleanup ();
}See also
Summary
When JERRY_FEATURE_VM_EXEC_STOP is enabled a callback function can be specified by this function. This callback is periodically called when JerryScript executes an ECMAScript program.
If the callback returns with undefined value the ECMAScript execution continues. Otherwise the result is thrown by the engine (if the error flag is not set for the returned value the engine automatically sets it). The callback function might be called again even if it threw an error. In this case the function must throw the same error again.
To reduce the CPU overhead of constantly checking the termination
condition the callback is called when a backward jump is executed
or an exception is caught. Setting the frequency to a greater
than 1 value reduces this overhead further. If its value is N
only every Nth event (backward jump, etc.) trigger the next check.
Prototype
void
jerry_set_vm_exec_stop_callback (jerry_vm_exec_stop_callback_t stop_cb,
void *user_p,
uint32_t frequency);stop_cb- periodically called callback (passing NULL disables this feature)user_p- user pointer passed to thestop_cbfunctionfrequency- frequency of calling thestop_cbfunction
Example
#include <string.h>
#include "jerryscript.h"
static int countdown = 10;
static jerry_value_t
vm_exec_stop_callback (void *user_p)
{
while (countdown > 0)
{
countdown--;
return jerry_create_undefined ();
}
// The error flag is added automatically.
return jerry_create_string ((const jerry_char_t *) "Abort script");
}
int
main (void)
{
jerry_init (JERRY_INIT_EMPTY);
jerry_set_vm_exec_stop_callback (vm_exec_stop_callback, &countdown, 16);
// Inifinte loop.
const char *src_p = "while(true) {}";
jerry_value_t src = jerry_parse ((jerry_char_t *) src_p, strlen (src_p), false);
jerry_release_value (jerry_run (src));
jerry_release_value (src);
jerry_cleanup ();
}See also
Summary
Get the byte length property of the ArrayBuffer. This is the same value which was passed to the ArrayBuffer constructor call.
Prototype
jerry_length_t
jerry_get_arraybuffer_byte_length (const jerry_value_t value);value- ArrayBuffer object- return value
- size of the ArrayBuffer in bytes
- 0 if the
valueparameter is not an ArrayBuffer
Example
{
jerry_value_t buffer = jerry_create_arraybuffer (15);
jerry_length_t length = jerry_get_arraybuffer_byte_length (buffer);
// length should be 15
jerry_release_value (buffer);
}See also
Summary
Copy the portion of the ArrayBuffer into a user provided buffer. The start offset of the read operation can be specified.
The number bytes to be read can be specified via the buf_size
parameter. It is not possible to read more than the length of
the ArrayBuffer.
Function returns the number of bytes read from the ArrayBuffer
(and written to the buffer parameter). This value is
calculated in the following way: min(array buffer length - offset, buf_size).
Prototype
jerry_length_t
jerry_arraybuffer_read (const jerry_value_t value,
jerry_length_t offset,
uint8_t *buf_p,
jerry_length_t buf_size);value- ArrayBuffer to read fromoffset- start offset of the read operationbuf_p- buffer to read the data tobuf_size- maximum number of bytes to read into the buffer- return value
- number of bytes written into the buffer (read from the ArrayBuffer)
- 0 if the
valueis not an ArrayBuffer object - 0 if the
buf_sizeis zero or there is nothing to read
Example
{
uint8_t data[20];
jerry_value_t buffer;
// ... create the ArrayBuffer or acuiqre it from somewhere.
jerry_value_t bytes_read;
// read 10 bytes from the start of the ArrayBuffer.
bytes_read = jerry_arraybuffer_read (buffer, 0, data, 10);
// read the next 10 bytes
bytes_read += jerry_arraybuffer_read (buffer, bytes_read, data + bytes_read, 10);
// process the data variable
jerry_release_value (buffer);
}See also
Summary
Copy the contents of a buffer into the ArrayBuffer. The start offset of the write operation can be specified.
The number bytes to be written can be specified via the buf_size
parameter. It is not possible to write more than the length of
the ArrayBuffer.
Function returns the number of bytes written into the ArrayBuffer
(and read from the buffer parameter). This value is
calculated in the following way: min(array buffer length - offset, buf_size).
Prototype
jerry_length_t
jerry_arraybuffer_write (const jerry_value_t value,
jerry_length_t offset,
const uint8_t *buf_p,
jerry_length_t buf_size);value- ArrayBuffer to write tooffset- start offset of the write operationbuf_p- buffer to read the data frombuf_size- maximum number of bytes to write into the ArrayBuffer- return value
- number of bytes written into the ArrayBuffer (read from the buffer parameter)
- 0 if the
valueis not an ArrayBuffer object - 0 if the
buf_sizeis zero or there is nothing to write
Example
{
uint8_t data[20];
// fill the data with values
for (int i = 0; i < 20; i++)
{
data[i] = (uint8_t) (i * 2);
}
jerry_value_t buffer;
// ... create the ArrayBuffer or acquire it from somewhere.
jerry_value_t bytes_written;
// write 10 bytes from to the start of the ArrayBuffer.
bytes_written = jerry_arraybuffer_write (buffer, 0, data, 10);
// read the next 10 bytes
bytes_written += jerry_arraybuffer_write (buffer, bytes_written, data + bytes_written, 10);
// use the ArrayBuffer
jerry_release_value (buffer);
}See also
Summary
The function allows access to the contents of the Array Buffer directly.
Only allowed for Array Buffers which were created with
jerry_create_arraybuffer_external
function calls. In any other case this function will return NULL.
After using the pointer the jerry_release_value function must be called.
WARNING! This operation is for expert use only! The programmer must ensure that the returned memory area is used correctly. That is there is no out of bounds reads or writes.
Prototype
uint8_t *
jerry_get_arraybuffer_pointer (const jerry_value_t value);value- Array Buffer object.- return value
- pointer to the Array Buffer's data area.
- NULL if the
valueis not an Array Buffer object with external memory.
Example
{
jerry_value_t buffer;
// acquire buffer somewhere which was created by a jerry_create_array_buffer_external call.
uint8_t *const data = jerry_get_arraybuffer_pointer (buffer);
for (int i = 0; i < 22; i++)
{
data[i] = (uint8_t) (i + 4);
}
// required after jerry_get_arraybuffer_pointer call.
jerry_release_value (buffer);
// use the Array Buffer
// release buffer as it is not needed after this point
jerry_release_value (buffer);
}See also
Summary
Get the type of the TypedArray.
The returned type is one of the jerry_typedarray_type_t enum value.
Prototype
jerry_typedarray_type_t
jerry_get_typedarray_type (jerry_value_t value);value- TypedArray object to query for type.- return
- the type of the TypedArray
- JERRY_TYPEDARRAY_INVALID if the object was not a TypedArray
Example
{
jerry_typedarray_type_t expected_type = JERRY_TYPEDARRAY_UINT32;
jerry_value_t typedarray = jerry_create_typedarray (expected_klass, 25);
jerry_typedarray_type_t type = jerry_get_typedarray_type (typedarray);
// 'type' is now JERRY_TYPEDARRAY_UINT32
jerry_release_value (typedarray);
}See also
Summary
Get the element count of the TypedArray as specified during creation.
This is not the same as the byteLength property of a TypedArray object.
Prototype
jerry_length_t
jerry_get_typedarray_length (jerry_value_t value);
value- TypedArray object to query- return
- length (element count) of the TypedArray object
- 0 if the object is not a TypedArray
Example
{
jerry_value_t array = jerry_create_typedarray (JERRY_TYPEDARRAY_INT32, 21);
jerry_length_t element_count = jerry_get_typedarray_length (array);
// element_count is now 21.
jerry_release_value (array);
}See also
Summary
Get the ArrayBuffer object used by a TypedArray object. Additionally returns the byteLength and byteOffset properties of the TypedArray object.
For the returned ArrayBuffer the jerry_release_value must be called.
Prototype
jerry_value_t jerry_get_typedarray_buffer (jerry_value_t value,
jerry_length_t *byteOffset,
jerry_length_t *byteLength);value- TypedArray to get the ArrayBuffer frombyteOffset- (Optional) returns the start offset of the ArrayBuffer for the TypedArraybyteLength- (Optional) returns the number of bytes used from the ArrayBuffer for the TypedArray- return
- TypedArray object's underlying ArrayBuffer object
- TypeError if the
valueis not a TypedArray object
Example
{
jerry_value_t array = jerry_create_typedarray (JERRY_TYPEDARRAY_INT16, 11);
jerry_length_t byteLength = 0;
jerry_length_t byteOffset = 0;
jerry_value_t buffer = jerry_get_typedarray_buffer (array, &byteOffset, &byteLength);
// buffer is an ArrayBuffer object and ArrayBuffer operations can be performed on it
// byteLength is 11 * 2 (2 as the TypedArray stores Int16 that is 2 byte elements)
// byteOffset is 0
jerry_release_value (buffer);
jerry_release_value (array);
}See also