List of known issues

As thinBASIC formal checking is currently under careful research, it might be useful for you to know about the current limitations of the language, which might otherwise confuse you.

SWAP

This useful command for swapping variable content is silently accepting UDT variable or member as a parameter, but it does not perform any action.

DANGER: - missing functionality silently ignored, reported

There is a workaround, which allows you to achieve the desired effect:

TYPE Point2D
  x AS SINGLE
  y AS SINGLE
END TYPE

DIM a AS Point2D
a.x = 1

DIM b AS Point2D
b.x = 2

MSGBOX 0, "a: x=" + a.x + ", y=" + a.y + $CRLF + 
          "b: x=" + b.x + ", y=" + b.y, %MB_OK, "Before swap"

' SWAP a, b ' DOES NOT work at the moment
MEMORY_SWAP(varptr(a), varptr(b), sizeof(Point2D))

MSGBOX 0, "a: x=" + a.x + ", y=" + a.y + $CRLF + 
          "b: x=" + b.x + ", y=" + b.y, %MB_OK, "After swap"

Also, SWAP will trigger a confusing message when used on UDT elements directly, reported

Again, there is a workaround to get around this limitation:

TYPE Point2D
  x AS SINGLE
  y AS SINGLE
END TYPE

DIM a AS Point2D
a.x = 1
a.y = 100

DIM b AS Point2D
b.x = 2
b.y = 200

MSGBOX 0, "a: x=" + a.x + ", y=" + a.y + $CRLF + 
          "b: x=" + b.x + ", y=" + b.y, %MB_OK, "Before swap"

'SWAP a.y, b.y ' DOES NOT work at the moment
MEMORY_SWAP(varptr(a.y), varptr(b.y), sizeof(a.y))

MSGBOX 0, "a: x=" + a.x + ", y=" + a.y + $CRLF + 
          "b: x=" + b.x + ", y=" + b.y, %MB_OK, "After swap"

Direct assignment

While this is not an issue, it is good to know about how this works.

When you perform the assignment of one UDT variable to another UDT variable, a copy of data is performed.

TYPE Point2D
  x AS SINGLE
  y AS SINGLE
END TYPE

dim a as Point2D
a.x = 1

dim b as Point2D
b.x = 2

a = b

MSGBOX 0, a.x
MSGBOX 0, b.x

Please note thinBASIC currently allows you to assign two totally different types, as it performs a memory copy.

TYPE Point2D
  x AS SINGLE
  y AS SINGLE
END TYPE

TYPE Point3D
  x AS SINGLE
  y AS SINGLE
  z AS SINGLE
END TYPE

dim a as Point2D
a.x = 1

dim b as Point3D
b.x = 2

a = b

MSGBOX 0, a.x
MSGBOX 0, b.x

DANGER: - allows you to miss the accidental assignment of incompatible data types.

Arrays in UDT

The following functions do not work with UDT arrays yet:

ARRAY ASSIGN, reported
ARRAY EXTRACT, reported
ARRAY FILL, reported
ARRAY SCAN, reported
ARRAY SORT, reported
ARRAY SUM, reported
ARRAY SHIFT, reported
ARRAY SHUFFLE, reported
ARRAY UNIQUE, reported
JOIN$, reported

You can workaround these limitations by overlaying virtual array over the UDT array.

Example:

TYPE MyType
  myArray() as int32
  
  function _Create()
    redim me.myArray(3)
    me.myArray(1) = 1, 2, 3
    
    ' This overlays local array over ME array,
    ' making ME.myArray data available for read/write
    int32 virtualMyArray(3) at varptr(me.myArray(1))
    
    int32 index = array scan virtualMyArray(), = 3
    
    msgbox 0, index
    
  end function
END TYPE

dim v as MyType

COUNTOF does not work, reported
- you can workaround by using UBOUND instead

Multidimensional dynamic arrays in UDT

While static multidimensional arrays in UDT are fully supported with up to 3 dimensions, the dynamic UDT arrays currently work only with a single dimension.

If you dimension dynamic UDT array with more than 1 dimension, it will silently continue, but the indexing will not work correctly.