\\ Tokenize a string str according to 1 character delimiter d. Return a list of tokens.
\\ Using ssubstr() from http://rosettacode.org/wiki/Substring#PARI.2FGP
\\ tokenize() 3/5/16 aev
tokenize(str,d)={
my(str=Str(str,d),vt=Vecsmall(str),d1=sasc(d),Lr=List(),sn=#str,v1,p1=1);
for(i=p1,sn, v1=vt[i]; if(v1==d1, listput(Lr,ssubstr(str,p1,i-p1)); p1=i+1));
return(Lr);
}

{
\\ TEST
print(" *** Testing tokenize from Version #1:");
print("1.", tokenize("Hello,How,Are,You,Today",","));
\\ BOTH 2 & 3 are NOT OK!!
print("2.",tokenize("Hello,How,Are,You,Today,",","));
print("3.",tokenize(",Hello,,How,Are,You,Today",","));
}