Function as parameter to another function

[Henko]

It is not mentioned explicitly in the sB help info, but a function name may be passed to another function in the parameter list.

Code: Select all

x=3 ! prt(f(x))
end

def prt(x) ! print x ! end def

def f(x)
  return 4*x-3
end def

[matt7]

I don't think that's what is happening in your example. f(x) is being evaluated first, and then its return value is passed to function prt.

[matt7]

I have often times run into situations where function pointers would have been helpful, but I have refrained from requesting that feature because I thought it was a bit too far out of the realm of what Basic languages normally do.

My alternative has been to use numerical enumerations (but you could just use strings if you wanted to):

Code: Select all

' Enumeration for selected color mode:
(I usually put all enumerations for a program in one library file)
COLOR_MODE_RGB = 1
COLOR_MODE_HSL = 2

' . . .

' Then everywhere else in the program, I can refer to these with the variable names instead of memorizing that RGB is 1 and HSL is 2
SWITCH_TO_COLOR_MODE(COLOR_MODE_RGB)

' . . .

DEF SWITCH_TO_COLOR_MODE(cm)

  IF cm = COLOR_MODE_RGB THEN
    ' ...
  ELSE ' cm = COLOR_MODE_HSL
    ' ...
  END IF

END DEF

[Mr. Kibernetik]

Yes, functions as parameters is too much for BASIC language.
In my SPL language functions are the same objects as any other assignable object and can be passed as function parameters, saved into variables and so on. But this is very sophisticated for BASIC functionality.

[Henko]

It is not mentioned explicitly in the sB help info, but a function name may be passed to another function in the parameter list.

Code: Select all

x=3 ! prt(f(x))
end

def prt(x) ! print x ! end def

def f(x)
  return 4*x-3
end def

Yes, Matt is right of course. The "def prt(x)" clearly indicates that a value is expected.