CDE

Task/Exponentiation-operator/REXX/exponentiation-operator.rexx

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+/*REXX program to show  various   (integer)  exponentations.            */
+                                say center('digits='digits(),79,'─')
+say '17**65   is:'
+say  17**65
+
+numeric digits 100;    say;     say center('digits='digits(),79,'─')
+say '17**65   is:'
+say  17**65
+
+numeric digits 10;     say;     say center('digits='digits(),79,'─')
+say '2 ** -10   is:'
+say  2 ** -10
+
+numeric digits 30;     say;     say center('digits='digits(),79,'─')
+say '-3.1415926535897932384626433 ** 3  is:'
+say  -3.1415926535897932384626433 ** 3
+
+numeric digits 1000;   say;     say center('digits='digits(),79,'─')
+say '2 ** 1000   is:'
+say  2 ** 1000
+
+numeric digits 60;     say;     say center('digits='digits(),79,'─')
+say 'ipow(5,70)  is:'
+say  ipow(5,70)
+exit                                   /*stick a fork in it, we're done.*/
+/*──────────────────────────────────ERRIPOW subroutine──────────────────*/
+errIpow: say;  say '***error!***';  say;  say arg(1);  say;  say;  exit 13
+/*──────────────────────────────────IPOW subroutine─────────────────────*/
+ipow:  procedure;  parse arg x 1 _,p
+if arg()<2           then call erripow 'not enough arguments specified'
+if arg()>2           then call erripow 'too many arguments specified'
+if \datatype(_,'N')  then call erripow "1st arg isn't numeric:" _
+if \datatype(p,'W')  then call erripow "2nd arg isn't an integer:" p
+if p=0               then return 1
+pa=abs(p)
+                     do pa-1;   _=_*x;   end
+if p<0 then _=1/_
+return _