VOL-381 add unum container to support ONOS cluster formation under swarm
Change-Id: Ic260edda19bb199ed040f05164ab605f28c919d0
diff --git a/unum/vendor/github.com/docker/distribution/reference/helpers.go b/unum/vendor/github.com/docker/distribution/reference/helpers.go
new file mode 100644
index 0000000..978df7e
--- /dev/null
+++ b/unum/vendor/github.com/docker/distribution/reference/helpers.go
@@ -0,0 +1,42 @@
+package reference
+
+import "path"
+
+// IsNameOnly returns true if reference only contains a repo name.
+func IsNameOnly(ref Named) bool {
+ if _, ok := ref.(NamedTagged); ok {
+ return false
+ }
+ if _, ok := ref.(Canonical); ok {
+ return false
+ }
+ return true
+}
+
+// FamiliarName returns the familiar name string
+// for the given named, familiarizing if needed.
+func FamiliarName(ref Named) string {
+ if nn, ok := ref.(normalizedNamed); ok {
+ return nn.Familiar().Name()
+ }
+ return ref.Name()
+}
+
+// FamiliarString returns the familiar string representation
+// for the given reference, familiarizing if needed.
+func FamiliarString(ref Reference) string {
+ if nn, ok := ref.(normalizedNamed); ok {
+ return nn.Familiar().String()
+ }
+ return ref.String()
+}
+
+// FamiliarMatch reports whether ref matches the specified pattern.
+// See https://godoc.org/path#Match for supported patterns.
+func FamiliarMatch(pattern string, ref Reference) (bool, error) {
+ matched, err := path.Match(pattern, FamiliarString(ref))
+ if namedRef, isNamed := ref.(Named); isNamed && !matched {
+ matched, _ = path.Match(pattern, FamiliarName(namedRef))
+ }
+ return matched, err
+}
diff --git a/unum/vendor/github.com/docker/distribution/reference/normalize.go b/unum/vendor/github.com/docker/distribution/reference/normalize.go
new file mode 100644
index 0000000..2d71fc5
--- /dev/null
+++ b/unum/vendor/github.com/docker/distribution/reference/normalize.go
@@ -0,0 +1,170 @@
+package reference
+
+import (
+ "errors"
+ "fmt"
+ "strings"
+
+ "github.com/docker/distribution/digestset"
+ "github.com/opencontainers/go-digest"
+)
+
+var (
+ legacyDefaultDomain = "index.docker.io"
+ defaultDomain = "docker.io"
+ officialRepoName = "library"
+ defaultTag = "latest"
+)
+
+// normalizedNamed represents a name which has been
+// normalized and has a familiar form. A familiar name
+// is what is used in Docker UI. An example normalized
+// name is "docker.io/library/ubuntu" and corresponding
+// familiar name of "ubuntu".
+type normalizedNamed interface {
+ Named
+ Familiar() Named
+}
+
+// ParseNormalizedNamed parses a string into a named reference
+// transforming a familiar name from Docker UI to a fully
+// qualified reference. If the value may be an identifier
+// use ParseAnyReference.
+func ParseNormalizedNamed(s string) (Named, error) {
+ if ok := anchoredIdentifierRegexp.MatchString(s); ok {
+ return nil, fmt.Errorf("invalid repository name (%s), cannot specify 64-byte hexadecimal strings", s)
+ }
+ domain, remainder := splitDockerDomain(s)
+ var remoteName string
+ if tagSep := strings.IndexRune(remainder, ':'); tagSep > -1 {
+ remoteName = remainder[:tagSep]
+ } else {
+ remoteName = remainder
+ }
+ if strings.ToLower(remoteName) != remoteName {
+ return nil, errors.New("invalid reference format: repository name must be lowercase")
+ }
+
+ ref, err := Parse(domain + "/" + remainder)
+ if err != nil {
+ return nil, err
+ }
+ named, isNamed := ref.(Named)
+ if !isNamed {
+ return nil, fmt.Errorf("reference %s has no name", ref.String())
+ }
+ return named, nil
+}
+
+// splitDockerDomain splits a repository name to domain and remotename string.
+// If no valid domain is found, the default domain is used. Repository name
+// needs to be already validated before.
+func splitDockerDomain(name string) (domain, remainder string) {
+ i := strings.IndexRune(name, '/')
+ if i == -1 || (!strings.ContainsAny(name[:i], ".:") && name[:i] != "localhost") {
+ domain, remainder = defaultDomain, name
+ } else {
+ domain, remainder = name[:i], name[i+1:]
+ }
+ if domain == legacyDefaultDomain {
+ domain = defaultDomain
+ }
+ if domain == defaultDomain && !strings.ContainsRune(remainder, '/') {
+ remainder = officialRepoName + "/" + remainder
+ }
+ return
+}
+
+// familiarizeName returns a shortened version of the name familiar
+// to to the Docker UI. Familiar names have the default domain
+// "docker.io" and "library/" repository prefix removed.
+// For example, "docker.io/library/redis" will have the familiar
+// name "redis" and "docker.io/dmcgowan/myapp" will be "dmcgowan/myapp".
+// Returns a familiarized named only reference.
+func familiarizeName(named namedRepository) repository {
+ repo := repository{
+ domain: named.Domain(),
+ path: named.Path(),
+ }
+
+ if repo.domain == defaultDomain {
+ repo.domain = ""
+ // Handle official repositories which have the pattern "library/<official repo name>"
+ if split := strings.Split(repo.path, "/"); len(split) == 2 && split[0] == officialRepoName {
+ repo.path = split[1]
+ }
+ }
+ return repo
+}
+
+func (r reference) Familiar() Named {
+ return reference{
+ namedRepository: familiarizeName(r.namedRepository),
+ tag: r.tag,
+ digest: r.digest,
+ }
+}
+
+func (r repository) Familiar() Named {
+ return familiarizeName(r)
+}
+
+func (t taggedReference) Familiar() Named {
+ return taggedReference{
+ namedRepository: familiarizeName(t.namedRepository),
+ tag: t.tag,
+ }
+}
+
+func (c canonicalReference) Familiar() Named {
+ return canonicalReference{
+ namedRepository: familiarizeName(c.namedRepository),
+ digest: c.digest,
+ }
+}
+
+// TagNameOnly adds the default tag "latest" to a reference if it only has
+// a repo name.
+func TagNameOnly(ref Named) Named {
+ if IsNameOnly(ref) {
+ namedTagged, err := WithTag(ref, defaultTag)
+ if err != nil {
+ // Default tag must be valid, to create a NamedTagged
+ // type with non-validated input the WithTag function
+ // should be used instead
+ panic(err)
+ }
+ return namedTagged
+ }
+ return ref
+}
+
+// ParseAnyReference parses a reference string as a possible identifier,
+// full digest, or familiar name.
+func ParseAnyReference(ref string) (Reference, error) {
+ if ok := anchoredIdentifierRegexp.MatchString(ref); ok {
+ return digestReference("sha256:" + ref), nil
+ }
+ if dgst, err := digest.Parse(ref); err == nil {
+ return digestReference(dgst), nil
+ }
+
+ return ParseNormalizedNamed(ref)
+}
+
+// ParseAnyReferenceWithSet parses a reference string as a possible short
+// identifier to be matched in a digest set, a full digest, or familiar name.
+func ParseAnyReferenceWithSet(ref string, ds *digestset.Set) (Reference, error) {
+ if ok := anchoredShortIdentifierRegexp.MatchString(ref); ok {
+ dgst, err := ds.Lookup(ref)
+ if err == nil {
+ return digestReference(dgst), nil
+ }
+ } else {
+ if dgst, err := digest.Parse(ref); err == nil {
+ return digestReference(dgst), nil
+ }
+ }
+
+ return ParseNormalizedNamed(ref)
+}
diff --git a/unum/vendor/github.com/docker/distribution/reference/reference.go b/unum/vendor/github.com/docker/distribution/reference/reference.go
new file mode 100644
index 0000000..2f66cca
--- /dev/null
+++ b/unum/vendor/github.com/docker/distribution/reference/reference.go
@@ -0,0 +1,433 @@
+// Package reference provides a general type to represent any way of referencing images within the registry.
+// Its main purpose is to abstract tags and digests (content-addressable hash).
+//
+// Grammar
+//
+// reference := name [ ":" tag ] [ "@" digest ]
+// name := [domain '/'] path-component ['/' path-component]*
+// domain := domain-component ['.' domain-component]* [':' port-number]
+// domain-component := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/
+// port-number := /[0-9]+/
+// path-component := alpha-numeric [separator alpha-numeric]*
+// alpha-numeric := /[a-z0-9]+/
+// separator := /[_.]|__|[-]*/
+//
+// tag := /[\w][\w.-]{0,127}/
+//
+// digest := digest-algorithm ":" digest-hex
+// digest-algorithm := digest-algorithm-component [ digest-algorithm-separator digest-algorithm-component ]*
+// digest-algorithm-separator := /[+.-_]/
+// digest-algorithm-component := /[A-Za-z][A-Za-z0-9]*/
+// digest-hex := /[0-9a-fA-F]{32,}/ ; At least 128 bit digest value
+//
+// identifier := /[a-f0-9]{64}/
+// short-identifier := /[a-f0-9]{6,64}/
+package reference
+
+import (
+ "errors"
+ "fmt"
+ "strings"
+
+ "github.com/opencontainers/go-digest"
+)
+
+const (
+ // NameTotalLengthMax is the maximum total number of characters in a repository name.
+ NameTotalLengthMax = 255
+)
+
+var (
+ // ErrReferenceInvalidFormat represents an error while trying to parse a string as a reference.
+ ErrReferenceInvalidFormat = errors.New("invalid reference format")
+
+ // ErrTagInvalidFormat represents an error while trying to parse a string as a tag.
+ ErrTagInvalidFormat = errors.New("invalid tag format")
+
+ // ErrDigestInvalidFormat represents an error while trying to parse a string as a tag.
+ ErrDigestInvalidFormat = errors.New("invalid digest format")
+
+ // ErrNameContainsUppercase is returned for invalid repository names that contain uppercase characters.
+ ErrNameContainsUppercase = errors.New("repository name must be lowercase")
+
+ // ErrNameEmpty is returned for empty, invalid repository names.
+ ErrNameEmpty = errors.New("repository name must have at least one component")
+
+ // ErrNameTooLong is returned when a repository name is longer than NameTotalLengthMax.
+ ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", NameTotalLengthMax)
+
+ // ErrNameNotCanonical is returned when a name is not canonical.
+ ErrNameNotCanonical = errors.New("repository name must be canonical")
+)
+
+// Reference is an opaque object reference identifier that may include
+// modifiers such as a hostname, name, tag, and digest.
+type Reference interface {
+ // String returns the full reference
+ String() string
+}
+
+// Field provides a wrapper type for resolving correct reference types when
+// working with encoding.
+type Field struct {
+ reference Reference
+}
+
+// AsField wraps a reference in a Field for encoding.
+func AsField(reference Reference) Field {
+ return Field{reference}
+}
+
+// Reference unwraps the reference type from the field to
+// return the Reference object. This object should be
+// of the appropriate type to further check for different
+// reference types.
+func (f Field) Reference() Reference {
+ return f.reference
+}
+
+// MarshalText serializes the field to byte text which
+// is the string of the reference.
+func (f Field) MarshalText() (p []byte, err error) {
+ return []byte(f.reference.String()), nil
+}
+
+// UnmarshalText parses text bytes by invoking the
+// reference parser to ensure the appropriately
+// typed reference object is wrapped by field.
+func (f *Field) UnmarshalText(p []byte) error {
+ r, err := Parse(string(p))
+ if err != nil {
+ return err
+ }
+
+ f.reference = r
+ return nil
+}
+
+// Named is an object with a full name
+type Named interface {
+ Reference
+ Name() string
+}
+
+// Tagged is an object which has a tag
+type Tagged interface {
+ Reference
+ Tag() string
+}
+
+// NamedTagged is an object including a name and tag.
+type NamedTagged interface {
+ Named
+ Tag() string
+}
+
+// Digested is an object which has a digest
+// in which it can be referenced by
+type Digested interface {
+ Reference
+ Digest() digest.Digest
+}
+
+// Canonical reference is an object with a fully unique
+// name including a name with domain and digest
+type Canonical interface {
+ Named
+ Digest() digest.Digest
+}
+
+// namedRepository is a reference to a repository with a name.
+// A namedRepository has both domain and path components.
+type namedRepository interface {
+ Named
+ Domain() string
+ Path() string
+}
+
+// Domain returns the domain part of the Named reference
+func Domain(named Named) string {
+ if r, ok := named.(namedRepository); ok {
+ return r.Domain()
+ }
+ domain, _ := splitDomain(named.Name())
+ return domain
+}
+
+// Path returns the name without the domain part of the Named reference
+func Path(named Named) (name string) {
+ if r, ok := named.(namedRepository); ok {
+ return r.Path()
+ }
+ _, path := splitDomain(named.Name())
+ return path
+}
+
+func splitDomain(name string) (string, string) {
+ match := anchoredNameRegexp.FindStringSubmatch(name)
+ if len(match) != 3 {
+ return "", name
+ }
+ return match[1], match[2]
+}
+
+// SplitHostname splits a named reference into a
+// hostname and name string. If no valid hostname is
+// found, the hostname is empty and the full value
+// is returned as name
+// DEPRECATED: Use Domain or Path
+func SplitHostname(named Named) (string, string) {
+ if r, ok := named.(namedRepository); ok {
+ return r.Domain(), r.Path()
+ }
+ return splitDomain(named.Name())
+}
+
+// Parse parses s and returns a syntactically valid Reference.
+// If an error was encountered it is returned, along with a nil Reference.
+// NOTE: Parse will not handle short digests.
+func Parse(s string) (Reference, error) {
+ matches := ReferenceRegexp.FindStringSubmatch(s)
+ if matches == nil {
+ if s == "" {
+ return nil, ErrNameEmpty
+ }
+ if ReferenceRegexp.FindStringSubmatch(strings.ToLower(s)) != nil {
+ return nil, ErrNameContainsUppercase
+ }
+ return nil, ErrReferenceInvalidFormat
+ }
+
+ if len(matches[1]) > NameTotalLengthMax {
+ return nil, ErrNameTooLong
+ }
+
+ var repo repository
+
+ nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1])
+ if nameMatch != nil && len(nameMatch) == 3 {
+ repo.domain = nameMatch[1]
+ repo.path = nameMatch[2]
+ } else {
+ repo.domain = ""
+ repo.path = matches[1]
+ }
+
+ ref := reference{
+ namedRepository: repo,
+ tag: matches[2],
+ }
+ if matches[3] != "" {
+ var err error
+ ref.digest, err = digest.Parse(matches[3])
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ r := getBestReferenceType(ref)
+ if r == nil {
+ return nil, ErrNameEmpty
+ }
+
+ return r, nil
+}
+
+// ParseNamed parses s and returns a syntactically valid reference implementing
+// the Named interface. The reference must have a name and be in the canonical
+// form, otherwise an error is returned.
+// If an error was encountered it is returned, along with a nil Reference.
+// NOTE: ParseNamed will not handle short digests.
+func ParseNamed(s string) (Named, error) {
+ named, err := ParseNormalizedNamed(s)
+ if err != nil {
+ return nil, err
+ }
+ if named.String() != s {
+ return nil, ErrNameNotCanonical
+ }
+ return named, nil
+}
+
+// WithName returns a named object representing the given string. If the input
+// is invalid ErrReferenceInvalidFormat will be returned.
+func WithName(name string) (Named, error) {
+ if len(name) > NameTotalLengthMax {
+ return nil, ErrNameTooLong
+ }
+
+ match := anchoredNameRegexp.FindStringSubmatch(name)
+ if match == nil || len(match) != 3 {
+ return nil, ErrReferenceInvalidFormat
+ }
+ return repository{
+ domain: match[1],
+ path: match[2],
+ }, nil
+}
+
+// WithTag combines the name from "name" and the tag from "tag" to form a
+// reference incorporating both the name and the tag.
+func WithTag(name Named, tag string) (NamedTagged, error) {
+ if !anchoredTagRegexp.MatchString(tag) {
+ return nil, ErrTagInvalidFormat
+ }
+ var repo repository
+ if r, ok := name.(namedRepository); ok {
+ repo.domain = r.Domain()
+ repo.path = r.Path()
+ } else {
+ repo.path = name.Name()
+ }
+ if canonical, ok := name.(Canonical); ok {
+ return reference{
+ namedRepository: repo,
+ tag: tag,
+ digest: canonical.Digest(),
+ }, nil
+ }
+ return taggedReference{
+ namedRepository: repo,
+ tag: tag,
+ }, nil
+}
+
+// WithDigest combines the name from "name" and the digest from "digest" to form
+// a reference incorporating both the name and the digest.
+func WithDigest(name Named, digest digest.Digest) (Canonical, error) {
+ if !anchoredDigestRegexp.MatchString(digest.String()) {
+ return nil, ErrDigestInvalidFormat
+ }
+ var repo repository
+ if r, ok := name.(namedRepository); ok {
+ repo.domain = r.Domain()
+ repo.path = r.Path()
+ } else {
+ repo.path = name.Name()
+ }
+ if tagged, ok := name.(Tagged); ok {
+ return reference{
+ namedRepository: repo,
+ tag: tagged.Tag(),
+ digest: digest,
+ }, nil
+ }
+ return canonicalReference{
+ namedRepository: repo,
+ digest: digest,
+ }, nil
+}
+
+// TrimNamed removes any tag or digest from the named reference.
+func TrimNamed(ref Named) Named {
+ domain, path := SplitHostname(ref)
+ return repository{
+ domain: domain,
+ path: path,
+ }
+}
+
+func getBestReferenceType(ref reference) Reference {
+ if ref.Name() == "" {
+ // Allow digest only references
+ if ref.digest != "" {
+ return digestReference(ref.digest)
+ }
+ return nil
+ }
+ if ref.tag == "" {
+ if ref.digest != "" {
+ return canonicalReference{
+ namedRepository: ref.namedRepository,
+ digest: ref.digest,
+ }
+ }
+ return ref.namedRepository
+ }
+ if ref.digest == "" {
+ return taggedReference{
+ namedRepository: ref.namedRepository,
+ tag: ref.tag,
+ }
+ }
+
+ return ref
+}
+
+type reference struct {
+ namedRepository
+ tag string
+ digest digest.Digest
+}
+
+func (r reference) String() string {
+ return r.Name() + ":" + r.tag + "@" + r.digest.String()
+}
+
+func (r reference) Tag() string {
+ return r.tag
+}
+
+func (r reference) Digest() digest.Digest {
+ return r.digest
+}
+
+type repository struct {
+ domain string
+ path string
+}
+
+func (r repository) String() string {
+ return r.Name()
+}
+
+func (r repository) Name() string {
+ if r.domain == "" {
+ return r.path
+ }
+ return r.domain + "/" + r.path
+}
+
+func (r repository) Domain() string {
+ return r.domain
+}
+
+func (r repository) Path() string {
+ return r.path
+}
+
+type digestReference digest.Digest
+
+func (d digestReference) String() string {
+ return digest.Digest(d).String()
+}
+
+func (d digestReference) Digest() digest.Digest {
+ return digest.Digest(d)
+}
+
+type taggedReference struct {
+ namedRepository
+ tag string
+}
+
+func (t taggedReference) String() string {
+ return t.Name() + ":" + t.tag
+}
+
+func (t taggedReference) Tag() string {
+ return t.tag
+}
+
+type canonicalReference struct {
+ namedRepository
+ digest digest.Digest
+}
+
+func (c canonicalReference) String() string {
+ return c.Name() + "@" + c.digest.String()
+}
+
+func (c canonicalReference) Digest() digest.Digest {
+ return c.digest
+}
diff --git a/unum/vendor/github.com/docker/distribution/reference/regexp.go b/unum/vendor/github.com/docker/distribution/reference/regexp.go
new file mode 100644
index 0000000..7860349
--- /dev/null
+++ b/unum/vendor/github.com/docker/distribution/reference/regexp.go
@@ -0,0 +1,143 @@
+package reference
+
+import "regexp"
+
+var (
+ // alphaNumericRegexp defines the alpha numeric atom, typically a
+ // component of names. This only allows lower case characters and digits.
+ alphaNumericRegexp = match(`[a-z0-9]+`)
+
+ // separatorRegexp defines the separators allowed to be embedded in name
+ // components. This allow one period, one or two underscore and multiple
+ // dashes.
+ separatorRegexp = match(`(?:[._]|__|[-]*)`)
+
+ // nameComponentRegexp restricts registry path component names to start
+ // with at least one letter or number, with following parts able to be
+ // separated by one period, one or two underscore and multiple dashes.
+ nameComponentRegexp = expression(
+ alphaNumericRegexp,
+ optional(repeated(separatorRegexp, alphaNumericRegexp)))
+
+ // domainComponentRegexp restricts the registry domain component of a
+ // repository name to start with a component as defined by DomainRegexp
+ // and followed by an optional port.
+ domainComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
+
+ // DomainRegexp defines the structure of potential domain components
+ // that may be part of image names. This is purposely a subset of what is
+ // allowed by DNS to ensure backwards compatibility with Docker image
+ // names.
+ DomainRegexp = expression(
+ domainComponentRegexp,
+ optional(repeated(literal(`.`), domainComponentRegexp)),
+ optional(literal(`:`), match(`[0-9]+`)))
+
+ // TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
+ TagRegexp = match(`[\w][\w.-]{0,127}`)
+
+ // anchoredTagRegexp matches valid tag names, anchored at the start and
+ // end of the matched string.
+ anchoredTagRegexp = anchored(TagRegexp)
+
+ // DigestRegexp matches valid digests.
+ DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
+
+ // anchoredDigestRegexp matches valid digests, anchored at the start and
+ // end of the matched string.
+ anchoredDigestRegexp = anchored(DigestRegexp)
+
+ // NameRegexp is the format for the name component of references. The
+ // regexp has capturing groups for the domain and name part omitting
+ // the separating forward slash from either.
+ NameRegexp = expression(
+ optional(DomainRegexp, literal(`/`)),
+ nameComponentRegexp,
+ optional(repeated(literal(`/`), nameComponentRegexp)))
+
+ // anchoredNameRegexp is used to parse a name value, capturing the
+ // domain and trailing components.
+ anchoredNameRegexp = anchored(
+ optional(capture(DomainRegexp), literal(`/`)),
+ capture(nameComponentRegexp,
+ optional(repeated(literal(`/`), nameComponentRegexp))))
+
+ // ReferenceRegexp is the full supported format of a reference. The regexp
+ // is anchored and has capturing groups for name, tag, and digest
+ // components.
+ ReferenceRegexp = anchored(capture(NameRegexp),
+ optional(literal(":"), capture(TagRegexp)),
+ optional(literal("@"), capture(DigestRegexp)))
+
+ // IdentifierRegexp is the format for string identifier used as a
+ // content addressable identifier using sha256. These identifiers
+ // are like digests without the algorithm, since sha256 is used.
+ IdentifierRegexp = match(`([a-f0-9]{64})`)
+
+ // ShortIdentifierRegexp is the format used to represent a prefix
+ // of an identifier. A prefix may be used to match a sha256 identifier
+ // within a list of trusted identifiers.
+ ShortIdentifierRegexp = match(`([a-f0-9]{6,64})`)
+
+ // anchoredIdentifierRegexp is used to check or match an
+ // identifier value, anchored at start and end of string.
+ anchoredIdentifierRegexp = anchored(IdentifierRegexp)
+
+ // anchoredShortIdentifierRegexp is used to check if a value
+ // is a possible identifier prefix, anchored at start and end
+ // of string.
+ anchoredShortIdentifierRegexp = anchored(ShortIdentifierRegexp)
+)
+
+// match compiles the string to a regular expression.
+var match = regexp.MustCompile
+
+// literal compiles s into a literal regular expression, escaping any regexp
+// reserved characters.
+func literal(s string) *regexp.Regexp {
+ re := match(regexp.QuoteMeta(s))
+
+ if _, complete := re.LiteralPrefix(); !complete {
+ panic("must be a literal")
+ }
+
+ return re
+}
+
+// expression defines a full expression, where each regular expression must
+// follow the previous.
+func expression(res ...*regexp.Regexp) *regexp.Regexp {
+ var s string
+ for _, re := range res {
+ s += re.String()
+ }
+
+ return match(s)
+}
+
+// optional wraps the expression in a non-capturing group and makes the
+// production optional.
+func optional(res ...*regexp.Regexp) *regexp.Regexp {
+ return match(group(expression(res...)).String() + `?`)
+}
+
+// repeated wraps the regexp in a non-capturing group to get one or more
+// matches.
+func repeated(res ...*regexp.Regexp) *regexp.Regexp {
+ return match(group(expression(res...)).String() + `+`)
+}
+
+// group wraps the regexp in a non-capturing group.
+func group(res ...*regexp.Regexp) *regexp.Regexp {
+ return match(`(?:` + expression(res...).String() + `)`)
+}
+
+// capture wraps the expression in a capturing group.
+func capture(res ...*regexp.Regexp) *regexp.Regexp {
+ return match(`(` + expression(res...).String() + `)`)
+}
+
+// anchored anchors the regular expression by adding start and end delimiters.
+func anchored(res ...*regexp.Regexp) *regexp.Regexp {
+ return match(`^` + expression(res...).String() + `$`)
+}