MemoryBlock

is a memory area in the working memory (SRAM), actually it is a memory object in Luna's dynamicly managed memory. Creating a block reserves that number of Byte in memory an can be used to manage your data. Access to the object via the object methods only because it is managed dynamicly, e.g. the addresses change dynamicly. Call the „New“-Method to create a Memory Block. The maximus size are 65KB.

Create a new MemoryBlock

dim myvar as MemoryBlock
myvar = New MemoryBlock(numBytes)

Release a MemoryBlock

The release of a memory block occurs automatically when assigning a new memory block, and departure from a method, except it is a global variable, a reference („byRef“ parameter) or a static variable („dim x as static …“). Code-Examples for explanation see bottom.

Methods (read only)
Name Description Return Type
.Addr Address of the variable in memory word
.Ptr Address of the allocated memory block word
.Size Total number of Bytes of the allocated memory block word
Methods (read / write)
Name Description Return type
.ByteValue(offset) Read/Write Byte byte
.WordValue(offset) Read/Write Word word
.IntegerValue(offset) Read/Write Integer integer
.LongValue(offset) Read/Write Long long
.SingleValue(offset) Read/Write Single single
.StringValue(offset,bytes) Read/Write String of fixed length string
.PString(offset) Read/Write Pascal-String (Start-Byte is the length information) string
.CString(offset) Read/Write C-String (Null terminated) string

* offset: Byte-Position within the memory block, basis 0.

  • bytes: Number of Byte to read.

Notice

Memory Block boundry violation is permitted and not validated (faster). You may define a exception.

See also: Memory Management, Sram, Dump

Examples

dim a as byte
dim s as string
dim m as MemoryBlock
m.New(100) ' Create Memory Block and release exising block, if defined
if m <> nil then                     ' Check to see if memory block was allocated
  m.ByteValue(0)=7                   ' Write Byte
  m.CString(1)="I am a String"  ' Write String
  a=m.ByteValue(0) ' Read Byte, output: 7
  s=m.CString(1)   ' Read C-String, output: "I am a String"
  m.free           ' Release Objekt memory
end if

Examples for automatic release.

procedure test(m as MemoryBlock)
  'm is byVal and destroyed at return
endproc
procedure test()
  dim m as MemoryBlock
  'm is byVal and destroyed at return
endproc
procedure test(byRef m as MemoryBlock)
  'm is byRef and remains untouched
endproc
dim m as MemoryBlock
 
procedure test()
  'm is not part of the method and remains untouched
  'Reason:  
  'Visibility of global variables in methods as long as no separate
  'Variable with the same name was declared in the method
endproc
function test(byRef m as MemoryBlock) as MemoryBlock
  'm is byRef and remains untouched
  return m 'returns a new instance of m
endfunc
function test() as MemoryBlock
  dim m as MemoryBlock  
  return m 'the memoryBlock is dereferenced (detached) from "m" and returned
endfunc