_MEMELEMENT
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Note: _MEM and _OFFSET values cannot be cast to other variable types.
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The _MEMELEMENT function returns a _MEM block referring to a variable's memory, but not past it.
Syntax
- memoryBlock = _MEMELEMENT(referenceVariable)
- The referenceVariable parameter designates the existing variable name using the memory block.
- _MEMELEMENT is the same as _MEM but in an array it returns the specifications of an element, not the entire array.
- All values created by memory functions MUST be freed using _MEMFREE with a valid _MEM variable type.
- The _MEMELEMENT type contains the following read-only elements where name is the variable name:
- 2 = INTEGER values have an element size of 2 bytes
- 4 = LONG integer and SINGLE float values have an element size of 4 bytes
- 8 = DOUBLE float and _INTEGER64 values have an element size of 8 bytes
- 32 = _FLOAT values have an element size of 32 bytes
- LEN = STRING or _OFFSET byte sizes vary so use LEN(variable) for the number of bytes.
- name.TYPE is the type (represented as bits combined to form a value) AS LONG (see below).
.TYPE values (version 1.000 and up)
- 0 = UDT (user defined type) or memory created by _MEMNEW
- 1 = 1 bit ELEMENT.SIZE=1 *Only used along with specific types (currently integers or floats)
- 2 = 2 bit. ELEMENT.SIZE=2 *
- 4 = 4 bit. ELEMENT.SIZE=4 *
- 8 = 8 bit. ELEMENT.SIZE=8 *
- 16 = 16 bit. ELEMENT.SIZE=16 *
- 32 = 32 bit. ELEMENT.SIZE=32 *
- 64 = 64 bit. ELEMENT.SIZE=64 *
- 128 = 128 bit. ELEMENT.SIZE=128 *
- 256 = 256 bit. ELEMENT.SIZE=256 *
- 512(+ bit*) = integer types only(ie. whole numbers)
- 1024(+ bit*) = floating point types only(ie. numbers that can have a decimal point)
- 2048 = STRING type only
- 4096(+ 512 + bit*) = _UNSIGNED integer type only
- 8192 = _MEM type only
- 16384(+ 512 + bit*)= _OFFSET type only
Note: If a future integer, float or other type doesn't have a size that is 1,2,4,8,16,32,64,128 or 256 it won't have a size-bit set.
Versions prior to 1.000
- 1 = Integer types such as _BYTE, INTEGER, LONG, _INTEGER64 or _OFFSET
- 2 = _UNSIGNED variable types. Value must be added to the variable type value.(2 cannot be used by itself)
- 3 = ALL _UNSIGNED INTEGER type values.(add 1 + 2)
- 4 = Floating point types such as SINGLE, DOUBLE or _FLOAT
- 8 = STRING
- 0 = unknown(eg. created with _MEMNEW) or user-defined-types
Examples
Example: Comparing the specifications returned by _MEM and _MEMELEMENT from an array.
DIM a(1 TO 100) AS _UNSIGNED _BYTE DIM m1 AS _MEM DIM m2 AS _MEM m1 = _MEM(a(50)) 'function returns information about array up to specific element PRINT m1.OFFSET, m1.SIZE, m1.TYPE, m1.ELEMENTSIZE m2 = _MEMELEMENT(a(50)) 'function returns information about the specific element PRINT m2.OFFSET, m2.SIZE, m2.TYPE, m2.ELEMENTSIZE END |
- Output using VERSION .954 ONLY .TYPE values: 1 (integer) + 2 (unsigned)
28377205 51 3 1 28377205 1 3 1 |
- Explanation: _MEM returns the info about the array to that element while _MEMELEMENT returns info about that element only.
- _MEM value returns the available array .SIZE as 51 bytes from the designated array element.
- _MEMELEMENT value returns the available element .SIZE as one byte.
See also