public static RString substring(RString text, RDouble first, RDouble last, ASTNode ast) {
int textSize = text.size();
int firstSize = first.size();
int lastSize = last.size();
int textIndex = 0;
int firstIndex = 0;
int lastIndex = 0;
if (textSize == 0) { return RString.EMPTY; }
if (firstSize == 0) { throw RError.getInvalidArgument(ast, "first"); }// not exactly R-warning
if (lastSize == 0) { throw RError.getInvalidArgument(ast, "last"); } // not exactly R-warning
int n = Math.max(textSize, Math.max(firstSize, lastSize));
String[] content = new String[n];
for (int i = 0; i < n; i++) {
double nfirst = first.getDouble(firstIndex++);
if (firstIndex == firstSize) {
firstIndex = 0;
}
double nlast = last.getDouble(lastIndex++);
if (lastIndex == lastSize) {
lastIndex = 0;
}
String str = text.getString(textIndex++);
if (textIndex == textSize) {
textIndex = 0;
}
if (!RDouble.RDoubleUtils.isNAorNaN(nfirst) && !RDouble.RDoubleUtils.isNAorNaN(nlast) && str != RString.NA) {
int stp = (int) nlast;
int len = str.length();
if (stp > len) {
stp = len;
}
content[i] = str.substring(((int) nfirst) - 1, stp);
} else {
content[i] = RString.NA;
}
}
return RString.RStringFactory.getFor(content);
}
