NewRPL: Default and optional arguments

[compsystems]

Hello

1: Optional arguments

In the following code, when executing the SUMa function, it waits for 3 arguments and returns 24

PHP Code:

«
   → a b c
   «
      a  b + c +
   »
»
'SUMa' STO
CLEAR 9 8 7 SUMa [enter] returns 24 


CLEAR 9 8 SUMa [enter] ERROR, TOO FEW ARGUMENTS

The second version of the previous code SUMb, using a global variable 'args', selects the type of code to execute

PHP Code:

«
   IF args 2 == THEN
    → a b
     «
        a b +
     »
   ELSE
     IF args 3 == THEN
       → a b c
       «
         a b + c +
       »
     ELSE
       "ERROR, TOO FEW ARGUMENTS"
     END
   END
»
'SUMb' STO
CLEAR 9 8 7 3 'args' STO SUMb @ 24
CLEAR 9 8 2 'args' STO SUMb @ 17 


My idea or notation is to specify those arguments in the following way OPERATORNAME←ARGS

PHP Code:

CLEAR 9 8 7 SUMb←3 @ 24
CLEAR 9 8 SUMb←2 @ 17 


Where the numeric value after ← stores the value in the temporary variable associated with the name of the current function # ←args

2: the other idea is to be able to specify the initial value

«
→ expr var = 'x'
«
expr var xOperator
»
»
'FNTa' STO

'x^3' FNTa←1 @ takes 1 unique argument and by default the second with value 'x'
'Y^3' 'Y' FNTa←2 or
'Y^3' 'Y' FNTa @ takes 2 arguments and overwrites the second with the value of 'Y'