startsWith(string, prefix)={
  string=Vec(string);
  prefix=Vec(prefix);
  if(#prefix > #string, return(0));
  for(i=1,#prefix,if(prefix[i]!=string[i], return(0)));
  1
};
contains(string, inner)={
  my(good);
  string=Vec(string);
  inner=Vec(inner);
  for(i=0,#string-#inner,
    good=1;
    for(j=1,#inner,
      if(inner[j]!=string[i+j], good=0; break)
    );
    if(good, return(i+1))
  );
  0
};
endsWith(string, suffix)={
  string=Vec(string);
  suffix=Vec(suffix);
  if(#suffix > #string, return(0));
  for(i=1,#suffix,if(prefix[i]!=string[i+#string-#suffix], return(0)));
  1
};