return -1
		}
		return r
	}

	for _, marked := range nextStdChunkTests {
		// marked is an expected output from markChunks.
		// If we delete the parens and pass it through markChunks,
		// we should get the original back.
		format := strings.Map(noParens, marked)
		out := markChunks(format)
		if out != marked {
			t.Errorf("nextStdChunk parses %q as %q, want %q", format, out, marked)
		}
	}
}