UDT problems

[justsomeguy]

btw: is
Code: (Select All)

Code: (Select All)

array AS _MEM

 
variable length?

Yes and No. You set the length when you set 'cMAXELEMENTS'. If you want to change the length of the '_MEM' you have to create a new one with the length desired and copy the contents from the old one to the new one, and not forget '_MEMFREE ' the old memory location.

I updated this code a bit and it allows for resizing the array. BEWARE there is no error checking, so if you try to 'set' or 'get' a value outside of whats allocated then it will pop an error.

Code: (Select All)

' Program to create an array of Doubles in a UDT
DIM AS LONG i
DIM AS DOUBLE v
CONST cMAXELEMENTS = 10

TYPE tARRAY
  array AS _MEM
END TYPE

DIM AS tARRAY object

SCREEN 12: _FONT 8

' initialize the array
createObject object, cMAXELEMENTS

' set the array to random values
PRINT "Create initial Values"
FOR i = 0 TO cMAXELEMENTS
  v = INT(RND * 5)
  setElement object, i, v
  PRINT "index:"; i; "->"; v
NEXT

' retrieve values from array
PRINT "Retrieve Values"
FOR i = 0 TO cMAXELEMENTS
  PRINT "index:"; i; "->"; getElement(object, i)
NEXT

'resize array
resizeObject object, cMAXELEMENTS * 2

' retrieve values from array
PRINT "Double the size of the array"
FOR i = 0 TO cMAXELEMENTS * 2
  PRINT "index:"; i; "->"; getElement(object, i)
NEXT

'resize array
resizeObject object, cMAXELEMENTS / 2

' retrieve values from array
PRINT "Half the size of the array"
FOR i = 0 TO cMAXELEMENTS / 2
  PRINT "index:"; i; "->"; getElement(object, i)
NEXT


SUB createObject (o AS tARRAY, size AS LONG)
  ' make array one larger than number of elements
  o.array = _MEMNEW((size + 1) * 8) ' 8 is the number of bytes in a double
END SUB

SUB resizeObject (o AS tARRAY, size AS LONG)
  DIM AS _MEM old
  DIM AS _OFFSET l
  DIM AS LONG iter
  ' Copy old _MEM to a temp _MEM
  old = o.array
  ' Create new array of the new size
  createObject o, size
  ' Copy data from old array to new array
  iter = 0: DO WHILE iter < o.array.SIZE AND iter < old.SIZE
    _MEMPUT o.array, o.array.OFFSET + iter, _MEMGET(old, old.OFFSET + iter, _BYTE) AS _BYTE
  iter = iter + 1: LOOP
  ' free old array
  _MEMFREE old
END SUB

FUNCTION getElement# (o AS tARRAY, element AS LONG)
  getElement = _MEMGET(o.array, o.array.OFFSET + (element * 8), DOUBLE)
END FUNCTION

SUB setElement (o AS tARRAY, element AS LONG, v AS DOUBLE)
  _MEMPUT o.array, o.array.OFFSET + (element * 8), v AS DOUBLE
END SUB