Pointer Functions

These functions are used to be able to perform pointer operations in EbsScript, as they are common e.g. in the C programming language.

The declaration of a pointer (a reference) is done by "^" in front of the type name.

The address of a variable is accessed by a "&" in front of the variable name.

The content of the address to which the pointer refers (i.e. the value stored there) can be accessed by placing a "^" after the pointer variable (dereferencing).

A variable of type pointer contains the memory address of a variable of a certain type (like integer, real...).

Simple example:

var realnumber : real;
pointertoreal : ^real;
pointertype : pointer;

begin

    realnumber := 7.0;
    pointertoreal := &realnumber;
    println ("using ^ on pointer: ", pointertoreal^ * pointertoreal^);
    pointertype := pointertoreal;
    pointertoreal^ := 8;
    println ("Square: ", realnumber * realnumber);
end.

Ausgabe:
using ^ on pointer: 49.0
Square: 64.0

Name	Purpose	Arguments	Return value	Example
copymem	copies a memory area. size = number of elementary data types.	1: POINTER: Destination 2: POINTER: Source 3: INTEGER: Size	None
dispose	releases the memory area again, which was allocated by function new to the object, to which the pointer indicates.	1: POINTER:	None	var pi:^integer; begin new(pi); pi^:=5; print (pi^); dispose(pi); end;
freemem	releases the memory area again, which was allocated by function getmem to the object, to which the pointer indicates.	1: POINTER:	None
getmem	creates a new pointer and allocates the necessary memory for the object, to which the pointer indicates. Count > 1: array of elements	1: POINTER: 2: INTEGER: Count	None
new	creates a new pointer and allocates the necessary memory for the object, to which the pointer indicates. Count > 1: array of elements	1: POINTER: 2: INTEGER: Count	None	var pi:^integer; begin new(pi); pi^:=5; print (pi^); dispose(pi); end;
sizeOf	Returns size of the Object or Variable	Type of object or variable	INTEGER	var i: integer; arr:array[1..10] of string; type rec_t = record i,j:integer; r:real; end; var r:rec_t; begin println(sizeof(i)); println(sizeof(arr)); println(sizeof(r)); println(sizeof(array [2..5] of string)); println(sizeof(array of string)); end. // Output 1 10 3 4 1
addr	Returns the address of the argument. Returns the same as the address operator &	variable	INTEGER	var i: integer; begin println(addr(i)); println(&i); end. // possible output 0x00000a80 0x00000a80

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