[nektro]

std.mem.TokenIterator already has a method by this name

[squeek502]

This will need to be rebased now that #15579 has been merged

The updated implementation to handle the other delimiter types could be something like:

        pub fn peek(self: *Self) ?[]const T {
            const start = self.index orelse return null;
            const end = if (switch (delimiter_type) {
                .sequence => indexOfPos(T, self.buffer, start, self.delimiter),
                .any => indexOfAnyPos(T, self.buffer, start, self.delimiter),
                .scalar => indexOfScalarPos(T, self.buffer, start, self.delimiter),
            }) |delim_start| delim_start else self.buffer.len;
            return self.buffer[start..end];
        }