@Override public RNode create(ASTNode call, RSymbol[] names, RNode[] exprs) { final ArgumentInfo ia = check(call, names, exprs); final int posText = ia.position("text"); final int posLast = ia.position("last"); final int posFirst = ia.position("first"); final RDouble defaultLast = RDouble.RDoubleFactory.getScalar(1000000); // FIXME slow, but perhaps the default is not used, anyway return new Builtin(call, names, exprs) { @Override public RAny doBuiltIn(Frame frame, RAny[] args) { RString text = args[posText].asString(); warn.naIntroduced = false; RDouble first = args[posFirst].asDouble(warn); RDouble last; last = posLast != -1 ? args[posLast].asDouble(warn) : defaultLast; RString res = substring(text, first, last, ast); if (warn.naIntroduced) { RContext.warning(ast, RError.NA_INTRODUCED_COERCION); } return res; } }; }