2017-09-23 10:01:46 +02:00
|
|
|
/*REXX program demonstrates handling an exception (negative #); catching is via a label.*/
|
2015-11-18 06:14:39 +00:00
|
|
|
do j=9 by -5
|
2017-09-23 10:01:46 +02:00
|
|
|
say 'the square root of ' j " is " sqrt(j)
|
2013-06-05 21:47:54 +00:00
|
|
|
end /*j*/
|
2017-09-23 10:01:46 +02:00
|
|
|
exit /*stick a fork in it, we're all done. */
|
|
|
|
|
/*──────────────────────────────────────────────────────────────────────────────────────*/
|
|
|
|
|
sqrt: procedure; parse arg x; if x=0 then return 0; d=digits(); h=d+6; m.=9
|
|
|
|
|
numeric digits; numeric form; if x<0 then signal .sqrtNeg
|
|
|
|
|
parse value format(x, 2, 1, , 0) 'E0' with g 'E' _ .; g=g * .5'e'_ % 2
|
|
|
|
|
do j=0 while h>9; m.j=h; h=h%2 + 1; end /*j*/
|
|
|
|
|
do k=j+5 to 0 by -1; numeric digits m.k; g=(g+x/g) * .5; end /*k*/
|
|
|
|
|
numeric digits d; return g/1
|
|
|
|
|
.sqrtNeg: say 'illegal SQRT argument (argument is negative):' x; exit 13
|
