address-operator#

Purpose#

Returns the address of a procedure or function for use with function pointers.

Format#

fptr = &procname

Parameters#

param procname:

Name of a procedure or function.

type procname:

procedure name

Returns#

return fptr:

Pointer to the procedure that can be passed to other functions.

rtype fptr:

function pointer

Examples#

Basic Function Pointer#

// Define a procedure
proc (1) = mySquare(x);
    retp(x .* x);
endp;

// Get pointer to procedure
fptr = &mySquare;

// Use with local declaration
local fptr:proc;

// Call through pointer
y = fptr(5);

y =    25.000000

Passing to Optimization Functions#

// Define objective function
proc (1) = objective(x);
    retp(x[1]^2 + x[2]^2);
endp;

// Pass to optimizer
x0 = { 1, 1 };
{ x, fval, retcode } = sqpSolveMT(&objective, x0);

Selecting Functions Dynamically#

proc (1) = add(a, b);
    retp(a + b);
endp;

proc (1) = mult(a, b);
    retp(a * b);
endp;

// Choose function at runtime
op = 1;
if op == 1;
    fn = &add;
else;
    fn = &mult;
endif;

local fn:proc;
result = fn(3, 4);

result =    7.0000000

Remarks#

Function pointers allow procedures to be passed as arguments to other procedures.
The pointer variable must be declared with local varname:proc before being called.
Commonly used with optimization routines, numerical integration, and callback functions.
The & must immediately precede the procedure name with no spaces.