Buffer

Buffer provides a way to access binary buffers in the filesystem or just in memory from Wren. Be aware that internally all number in Wren are doubles meaning that any method that writes anything other than a double will simply cast the double and if you have a value not representable by the desired data type this is undefined behaviour. Any method that reads or writes data to/from the buffer expects the pointer to be at least x bytes behind the size of the buffer, where x is the size of that datatype (the size of each datatype is documented below). If you attempt more bytes than are remaining after the pointer all the read meathods will return null.

You may write Buffers to file using write.

• new()
• open()
• open_from_pak()
• resize()
• size
• pointer
• read_double()
• write_double()
• read_float()
• write_float()
• read_uint64()
• write_uint64()
• read_uint32()
• write_uint32()
• read_uint16()
• write_uint16()
• read_uint8()
• write_uint8()
• read_int64()
• write_int64()
• read_int32()
• write_int32()
• read_int16()
• write_int16()
• read_int8()
• write_int8()
• read_string()
• write_string()
• read_bool()
• write_bool()

new

construct new(size)

Parameters

• size -> Num Size in bytes of the new buffer.

Creates a new buffer of size size.

open

open(filename)

Parameters

• filename -> String File to read the buffer from.

Loads a buffer from a file.

open_from_pak

open_from_pak(filename)

Parameters

• filename -> String File to read the buffer from.

Loads a buffer from a file in game.pak. See pak for more information.

resize

resize(size)

Parameters

• size -> Num Size in bytes of the buffer.

Resizes a buffer, does not move the pointer and retains all original data if the new size is larger than the previous one.

size

Read only: size

Returns the size of the buffer in bytes.

pointer

pointer=(val) pointer

Variable Type: Num - Where the pointer should be.

Where data is being read from and written to.

read_double

read_double()

Returns the next 8 bytes starting from pointer as a double, then moves the pointer that many bytes forward.

write_double

write_double(double)

Parameters

• double -> Num Value to write.

Writes a Num to the buffer as a double, moving the pointer 8 bytes forward.

read_float

read_float()

Returns the next 4 bytes starting from pointer as a float, then moves the pointer that many bytes forward.

write_float

write_float(float)

Parameters

• float -> Num Value to write.

Writes a Num to the buffer as a float, moving the pointer 4 bytes forward.

read_uint64

read_uint64()

Returns the next 8 bytes starting from pointer as a 64-bit unsigned integer, then moves the pointer that many bytes forward.

write_uint64

write_uint64(uint64)

Parameters

• uint64 -> Num Value to write.

Writes a Num to the buffer as a uint64, moving the pointer 8 bytes forward.

read_uint32

read_uint32()

Returns the next 4 bytes starting from pointer as a 32-bit unsigned integer, then moves the pointer that many bytes forward.

write_uint32

write_uint32(uint32)

Parameters

• uint32 -> Num Value to write.

Writes a Num to the buffer as a uint32, moving the pointer 4 bytes forward.

read_uint16

read_uint16()

Returns the next 2 bytes starting from pointer as a 16-bit unsigned integer, then moves the pointer that many bytes forward.

write_uint16

write_uint16(uint16)

Parameters

• uint16 -> Num Value to write.

Writes a Num to the buffer as a uint16, moving the pointer 2 bytes forward.

read_uint8

read_uint8()

Returns the next 1 byte starting from pointer as an 8-bit unsigned integer, then moves the pointer that many bytes forward.

write_uint8

write_uint8(uint8)

Parameters

• uint8 -> Num Value to write.

Writes a Num to the buffer as a uint8, moving the pointer 1 bytes forward.

read_int64

read_int64()

Returns the next 8 bytes starting from pointer as a 64-bit signed integer, then moves the pointer that many bytes forward.

write_int64

write_int64(int64)

Parameters

• int64 -> Num Value to write.

Writes a Num to the buffer as a int64, moving the pointer 8 bytes forward.

read_int32

read_int32()

Returns the next 4 bytes starting from pointer as a 32-bit signed integer, then moves the pointer that many bytes forward.

write_int32

write_int32(int32)

Parameters

• int32 -> Num Value to write.

Writes a Num to the buffer as a int32, moving the pointer 4 bytes forward.

read_int16

read_int16()

Returns the next 2 bytes starting from pointer as a 16-bit signed integer, then moves the pointer that many bytes forward.

write_int16

write_int16(int16)

Parameters

• int16 -> Num Value to write.

Writes a Num to the buffer as a int16, moving the pointer 2 bytes forward.

read_int8

read_int8()

Returns the next 1 byte starting from pointer as an 8-bit signed integer, then moves the pointer that many bytes forward.

write_int8

write_int8(int8)

Parameters

• int8 -> Num Value to write.

Writes a Num to the buffer as a int8, moving the pointer 1 bytes forward.

read_string

read_string(size)

Parameters

• size -> Num Desired size of the string.

Returns the next size bytes as a string, moving the pointer size forward.

Internally Buffer places a null-terminating character at the end of the string. Any 0 values within the next size characters are not accounted for and will result in the string not being of length size.

write_string

write_string(string)

Parameters

• string -> String String to write to the buffer.

Writes a string to the buffer, moving the pointer string.count forward. This does not write the null-terminating character to the buffer, as read_string does not require null-terminating characters in the buffer.

read_bool

read_bool()

Returns the next 1 byte starting from pointer as a boolean, then moves the pointer that many bytes forward.

write_bool

write_bool(bool)

Parameters

• bool -> Bool Value to write.

Writes a Bool to the buffer as a bool, moving the pointer 1 bytes forward.