RosettaCodeData/Task/Parametric-polymorphism/REXX/parametric-polymorphism.rexx
2018-06-22 20:57:24 +00:00

32 lines
3.1 KiB
Rexx

/*REXX program demonstrates (with displays) a method of parametric polymorphism. */
call newRoot 1.00, 3 /*new root, and also indicate 3 stems.*/
/* [↓] no need to label the stems. */
call addStem 1.10 /*a new stem and its initial value. */
call addStem 1.11 /*" " " " " " " */
call addStem 1.12 /*" " " " " " " */
call addStem 1.20 /*" " " " " " " */
call addStem 1.21 /*" " " " " " " */
call addStem 1.22 /*" " " " " " " */
call sayNodes /*display some nicely formatted values.*/
call modRoot 50 /*modRoot will add fifty to all stems. */
call sayNodes /*display some nicely formatted values.*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
addStem: nodes=nodes + 1; do j=1 for stems; root.nodes.j=arg(1); end; return
newRoot: parse arg @,stems; nodes=-1; call addStem copies('',9); call addStem @; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
modRoot: arg #; do j=1 for nodes /*traipse through all the defined nodes*/
do k=1 for stems
if datatype(root.j.k,'N') then root.j.k=root.j.k + # /*add bias.*/
end /*k*/ /* [↑] only add if numeric stem value.*/
end /*j*/
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
sayNodes: w=9; do j=0 to nodes; _= /*ensure each of the nodes gets shown. */
do k=1 for stems; _=_ center(root.j.k, w) /*concatenate a node*/
end /*k*/
$=word('node='j, 1 + (j<1) ) /*define a label for this line's output*/
say center($, w) substr(_, 2) /*ignore 1st (leading) blank which was */
end /*j*/ /* [↑] caused by concatenation.*/
say /*show a blank line to separate outputs*/
return /* [↑] extreme indentation to terminal*/