}
	writeRegexp(&b, re, must, flags)
	return b.String()
}

const meta = `\.+*?()|[]{}^$`

func escape(b *strings.Builder, r rune, force bool) {
	if unicode.IsPrint(r) {
		if strings.ContainsRune(meta, r) || force {
			b.WriteRune('\\')
		}
		b.WriteRune(r)
		return
	}

	switch r {
	case '\a':
		b.WriteString(`\a`)
	case '\f':
		b.WriteString(`\f`)
	case '\n':

	return
}

// Omit specify fields that you want to ignore when creating, updating and querying
func (db *DB) Omit(columns ...string) (tx *DB) {
	tx = db.getInstance()

	if len(columns) == 1 && strings.ContainsRune(columns[0], ',') {
		tx.Statement.Omits = strings.FieldsFunc(columns[0], utils.IsValidDBNameChar)
	} else {
		tx.Statement.Omits = columns
	}
	return
}

// Where add conditions
//

func isValidImport(s string) bool {
	const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
	for _, r := range s {
		if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
			return false
		}
	}
	return s != ""
}

// parseGoEmbed parses the text following "//go:embed" to extract the glob patterns.

		}
	}

	if cfg.BuildN || cfg.BuildX {
		var envcmdline string
		for _, e := range env {
			if j := strings.IndexByte(e, '='); j != -1 {
				if strings.ContainsRune(e[j+1:], '\'') {
					envcmdline += fmt.Sprintf("%s=%q", e[:j], e[j+1:])
				} else {
					envcmdline += fmt.Sprintf("%s='%s'", e[:j], e[j+1:])
				}
				envcmdline += " "
			}
		}

	{"a☺b☻c☹d", 'x', false},
	{"a☺b☻c☹d", '☻', true},
	{"aRegExp*", '*', true},
}

func TestContainsRune(t *testing.T) {
	for _, ct := range ContainsRuneTests {
		if ContainsRune(ct.str, ct.r) != ct.expected {
			t.Errorf("ContainsRune(%q, %q) = %v, want %v",
				ct.str, ct.r, !ct.expected, ct.expected)
		}
	}
}

func TestContainsFunc(t *testing.T) {
	for _, ct := range ContainsRuneTests {

	// containing spaces to be double quoted.
	var quote bool
	for i, arg := range args {
		if arg == "-iex" || arg == "-ex" {
			quote = true
		} else if quote {
			if strings.ContainsRune(arg, ' ') {
				args[i] = `"` + arg + `"`
			}
			quote = false
		}
	}
}

func TestGdbPython(t *testing.T) {
	testGdbPython(t, false)
}

func TestGdbPythonCgo(t *testing.T) {

		// We allow spaces (U+0020) in file names.
		const allowed = "!#$%&()+,-.=@[]^_{}~ "
		if '0' <= r && r <= '9' || 'A' <= r && r <= 'Z' || 'a' <= r && r <= 'z' {
			return true
		}
		return strings.ContainsRune(allowed, r)
	}
	// It may be OK to add more ASCII punctuation here, but only carefully.
	// For example Windows disallows < > \, and macOS disallows :, so we must not allow those.
	return unicode.IsLetter(r)
}

	}
	if s == "" {
		return "", fmt.Errorf("empty string")
	}
	const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
	for _, r := range s {
		if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
			return s, fmt.Errorf("invalid character %#U", r)
		}
	}
	return s, nil
}

// declarePkgObj declares obj in the package scope, records its ident -> obj mapping,

	}
	if s == "" {
		return "", fmt.Errorf("empty string")
	}
	const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
	for _, r := range s {
		if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
			return s, fmt.Errorf("invalid character %#U", r)
		}
	}
	return s, nil
}

// declarePkgObj declares obj in the package scope, records its ident -> obj mapping,

	{[]byte("a☺b☻c☹d"), '☻', true},
	{[]byte("aRegExp*"), '*', true},
}

func TestContainsRune(t *testing.T) {
	for _, ct := range ContainsRuneTests {
		if ContainsRune(ct.b, ct.r) != ct.expected {
			t.Errorf("ContainsRune(%q, %q) = %v, want %v",
				ct.b, ct.r, !ct.expected, ct.expected)
		}
	}
}

func TestContainsFunc(t *testing.T) {
	for _, ct := range ContainsRuneTests {