scanner := bufio.NewScanner(strings.NewReader(input))
	// Create a custom split function by wrapping the existing ScanWords function.
	split := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		advance, token, err = bufio.ScanWords(data, atEOF)
		if err == nil && token != nil {
			_, err = strconv.ParseInt(string(token), 10, 32)
		}
		return
	}
	// Set the split function for the scanning operation.

// longer slice starting at the same point in the input.
//
// The function is never called with an empty data slice unless atEOF
// is true. If atEOF is true, however, data may be non-empty and,
// as always, holds unprocessed text.
type SplitFunc func(data []byte, atEOF bool) (advance int, token []byte, err error)

// Errors returned by Scanner.
var (
	ErrTooLong         = errors.New("bufio.Scanner: token too long")

		if result != test.output {
			t.Errorf("%d: %q evaluated to %d; expected %d", i, test.input, result, test.output)
		}
		tok := p.next()
		if test.atEOF && tok.ScanToken != scanner.EOF {
			t.Errorf("%d: %q: at EOF got %s", i, test.input, tok)
		} else if !test.atEOF && tok.ScanToken == scanner.EOF {
			t.Errorf("%d: %q: expected not EOF but at EOF", i, test.input)
		}
	}
}

type badExprTest struct {
	input string

func TestSplitError(t *testing.T) {
	// Create a split function that delivers a little data, then a predictable error.
	numSplits := 0
	const okCount = 7
	errorSplit := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		if atEOF {
			panic("didn't get enough data")
		}
		if numSplits >= okCount {
			return 0, nil, testError
		}
		numSplits++
		return 1, data[0:1], nil
	}
	// Read the data.

		var current metaCacheEntry
		var atEOF, fnf, vnf, hasErr, agree int
		for i := range topEntries {
			topEntries[i] = metaCacheEntry{}
		}
		if contextCanceled(ctx) {
			return ctx.Err()
		}
		for i, r := range readers {
			if errs[i] != nil {
				hasErr++
				continue
			}
			entry, err := r.peek()
			switch err {
			case io.EOF:
				atEOF++
				continue
			case nil: