v0.0.58

confext/confParser.go

@@ -14,9 +14,21 @@ import (
 // ApplyEnvOverrides overrides field values from environment variables
 //
 // fields must be tagged with `env:"env_key"`
-func ApplyEnvOverrides[T any](c *T) error {
-
+//
+// only works on exported fields
+//
+// fields without an env tag are ignored
+// fields with an `env:"-"` tag are ignore
+//
+// sub-structs are recursively parsed (if they have an env tag) and the env-variable keys are delimited by the delim parameter
+// sub-structs with `env:""` are also parsed, but the delimited is skipped (they are handled as if they were one level higher)
+func ApplyEnvOverrides[T any](c *T, delim string) error {
 	rval := reflect.ValueOf(c).Elem()
+
+	return processEnvOverrides(rval, delim, "")
+}
+
+func processEnvOverrides(rval reflect.Value, delim string, prefix string) error {
 	rtyp := rval.Type()
 
 	for i := 0; i < rtyp.NumField(); i++ {
@@ -24,12 +36,36 @@ func ApplyEnvOverrides[T any](c *T) error {
 		rsfield := rtyp.Field(i)
 		rvfield := rval.Field(i)
 
-		envkey := rsfield.Tag.Get("env")
-		if envkey == "" {
+		if !rsfield.IsExported() {
 			continue
 		}
 
-		envval, efound := os.LookupEnv(envkey)
+		if rvfield.Kind() == reflect.Struct {
+
+			envkey, found := rsfield.Tag.Lookup("env")
+			if !found || envkey == "-" {
+				continue
+			}
+
+			subPrefix := prefix
+			if envkey != "" {
+				subPrefix = subPrefix + envkey + delim
+			}
+
+			err := processEnvOverrides(rvfield, delim, subPrefix)
+			if err != nil {
+				return err
+			}
+		}
+
+		envkey := rsfield.Tag.Get("env")
+		if envkey == "" || envkey == "-" {
+			continue
+		}
+
+		fullEnvKey := prefix + envkey
+
+		envval, efound := os.LookupEnv(fullEnvKey)
 		if !efound {
 			continue
 		}
@@ -38,86 +74,86 @@ func ApplyEnvOverrides[T any](c *T) error {
 
 			rvfield.Set(reflect.ValueOf(envval))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' () with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, bits.UintSize)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int64(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 64)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int64 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int64 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int64(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int32(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 32)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int32(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(int8(0)) {
 
 			envint, err := strconv.ParseInt(envval, 10, 8)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(int8(envint)))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, envval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
 
 		} else if rvfield.Type() == reflect.TypeOf(time.Duration(0)) {
 
 			dur, err := timeext.ParseDurationShortString(envval)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to duration (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to duration (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(dur))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, dur.String())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, dur.String())
 
 		} else if rvfield.Type() == reflect.TypeOf(time.UnixMilli(0)) {
 
 			tim, err := time.Parse(time.RFC3339Nano, envval)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to time.time (value := '%s')", envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to time.time (value := '%s')", fullEnvKey, envval))
 			}
 
 			rvfield.Set(reflect.ValueOf(tim))
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", envkey, tim.String())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, tim.String())
 
 		} else if rvfield.Type().ConvertibleTo(reflect.TypeOf(int(0))) {
 
 			envint, err := strconv.ParseInt(envval, 10, 8)
 			if err != nil {
-				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,int> (value := '%s')", rvfield.Type().Name(), envkey, envval))
+				return errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,int> (value := '%s')", rvfield.Type().Name(), fullEnvKey, envval))
 			}
 
 			envcvl := reflect.ValueOf(envint).Convert(rvfield.Type())
 
 			rvfield.Set(envcvl)
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", envkey, envcvl.Interface())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", fullEnvKey, envcvl.Interface())
 
 		} else if rvfield.Type().ConvertibleTo(reflect.TypeOf("")) {
 
@@ -125,7 +161,7 @@ func ApplyEnvOverrides[T any](c *T) error {
 
 			rvfield.Set(envcvl)
 
-			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", envkey, envcvl.Interface())
+			fmt.Printf("[CONF] Overwrite config '%s' with '%v'\n", fullEnvKey, envcvl.Interface())
 
 		} else {
 			return errors.New(fmt.Sprintf("Unknown kind/type in config: [ %s | %s ]", rvfield.Kind().String(), rvfield.Type().String()))

confext/confParser_test.go

@@ -1,6 +1,7 @@
 package confext
 
 import (
+	"gogs.mikescher.com/BlackForestBytes/goext/timeext"
 	"testing"
 	"time"
 )
@@ -40,7 +41,7 @@ func TestApplyEnvOverridesNoop(t *testing.T) {
 
 	output := input
 
-	err := ApplyEnvOverrides(&output)
+	err := ApplyEnvOverrides(&output, ".")
 	if err != nil {
 		t.Errorf("%v", err)
 		t.FailNow()
@@ -92,7 +93,7 @@ func TestApplyEnvOverridesSimple(t *testing.T) {
 	t.Setenv("TEST_V8", "1min4s")
 	t.Setenv("TEST_V9", "2009-11-10T23:00:00Z")
 
-	err := ApplyEnvOverrides(&data)
+	err := ApplyEnvOverrides(&data, ".")
 	if err != nil {
 		t.Errorf("%v", err)
 		t.FailNow()
@@ -109,6 +110,109 @@ func TestApplyEnvOverridesSimple(t *testing.T) {
 	assertEqual(t, data.V9, time.Unix(1257894000, 0).UTC())
 }
 
+func TestApplyEnvOverridesRecursive(t *testing.T) {
+
+	type subdata struct {
+		V1 int           `env:"SUB_V1"`
+		VX string        ``
+		V2 string        `env:"SUB_V2"`
+		V8 time.Duration `env:"SUB_V3"`
+		V9 time.Time     `env:"SUB_V4"`
+	}
+
+	type testdata struct {
+		V1   int     `env:"TEST_V1"`
+		VX   string  ``
+		Sub1 subdata ``
+		Sub2 subdata `env:"TEST_V2"`
+		Sub3 subdata `env:"TEST_V3"`
+		Sub4 subdata `env:""`
+		V5   string  `env:"-"`
+	}
+
+	data := testdata{
+		V1: 1,
+		VX: "2",
+		V5: "no",
+		Sub1: subdata{
+			V1: 3,
+			VX: "4",
+			V2: "5",
+			V8: 6 * time.Second,
+			V9: time.Date(2000, 1, 7, 1, 1, 1, 0, time.UTC),
+		},
+		Sub2: subdata{
+			V1: 8,
+			VX: "9",
+			V2: "10",
+			V8: 11 * time.Second,
+			V9: time.Date(2000, 1, 12, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub3: subdata{
+			V1: 13,
+			VX: "14",
+			V2: "15",
+			V8: 16 * time.Second,
+			V9: time.Date(2000, 1, 17, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub4: subdata{
+			V1: 18,
+			VX: "19",
+			V2: "20",
+			V8: 21 * time.Second,
+			V9: time.Date(2000, 1, 22, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+	}
+
+	t.Setenv("TEST_V1", "999")
+	t.Setenv("-", "yes")
+
+	t.Setenv("TEST_V2_SUB_V1", "846")
+	t.Setenv("TEST_V2_SUB_V2", "222_hello_world")
+	t.Setenv("TEST_V2_SUB_V3", "1min4s")
+	t.Setenv("TEST_V2_SUB_V4", "2009-11-10T23:00:00Z")
+
+	t.Setenv("TEST_V3_SUB_V1", "33846")
+	t.Setenv("TEST_V3_SUB_V2", "33_hello_world")
+	t.Setenv("TEST_V3_SUB_V3", "33min4s")
+	t.Setenv("TEST_V3_SUB_V4", "2033-11-10T23:00:00Z")
+
+	t.Setenv("SUB_V1", "11")
+	t.Setenv("SUB_V2", "22")
+	t.Setenv("SUB_V3", "33min")
+	t.Setenv("SUB_V4", "2044-01-01T00:00:00Z")
+
+	err := ApplyEnvOverrides(&data, "_")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	assertEqual(t, data.V1, 999)
+	assertEqual(t, data.VX, "2")
+	assertEqual(t, data.V5, "no")
+	assertEqual(t, data.Sub1.V1, 3)
+	assertEqual(t, data.Sub1.VX, "4")
+	assertEqual(t, data.Sub1.V2, "5")
+	assertEqual(t, data.Sub1.V8, time.Second*6)
+	assertEqual(t, data.Sub1.V9, time.Unix(947206861, 0).UTC())
+	assertEqual(t, data.Sub2.V1, 846)
+	assertEqual(t, data.Sub2.VX, "9")
+	assertEqual(t, data.Sub2.V2, "222_hello_world")
+	assertEqual(t, data.Sub2.V8, time.Second*64)
+	assertEqual(t, data.Sub2.V9, time.Unix(1257894000, 0).UTC())
+	assertEqual(t, data.Sub3.V1, 33846)
+	assertEqual(t, data.Sub3.VX, "14")
+	assertEqual(t, data.Sub3.V2, "33_hello_world")
+	assertEqual(t, data.Sub3.V8, time.Second*1984)
+	assertEqual(t, data.Sub3.V9, time.Unix(2015276400, 0).UTC())
+	assertEqual(t, data.Sub4.V1, 11)
+	assertEqual(t, data.Sub4.VX, "19")
+	assertEqual(t, data.Sub4.V2, "22")
+	assertEqual(t, data.Sub4.V8, time.Second*1980)
+	assertEqual(t, data.Sub4.V9, time.Unix(2335219200, 0).UTC())
+}
+
 func assertEqual[T comparable](t *testing.T, actual T, expected T) {
 	if actual != expected {
 		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)

cryptext/passHash.go

@@ -179,6 +179,101 @@ func (ph PassHash) Upgrade(plainpass string) (PassHash, error) {
 	}
 }
 
+func (ph PassHash) ClearTOTP() (PassHash, error) {
+	version, _, _, _, _, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return ph, nil
+	}
+
+	if version == 1 {
+		return ph, nil
+	}
+
+	if version == 2 {
+		return ph, nil
+	}
+
+	if version == 3 {
+		split := strings.Split(string(ph), "|")
+		split[3] = "0"
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	if version == 4 {
+		split := strings.Split(string(ph), "|")
+		split[2] = "0"
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	return "", errors.New("unknown version")
+}
+
+func (ph PassHash) WithTOTP(totpSecret []byte) (PassHash, error) {
+	version, _, _, _, _, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 1 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 2 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 3 {
+		split := strings.Split(string(ph), "|")
+		split[3] = hex.EncodeToString(totpSecret)
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	if version == 4 {
+		split := strings.Split(string(ph), "|")
+		split[2] = hex.EncodeToString(totpSecret)
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	return "", errors.New("unknown version")
+}
+
+func (ph PassHash) Change(newPlainPass string) (PassHash, error) {
+	version, _, _, hastotp, totpsecret, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return HashPasswordV0(newPlainPass)
+	}
+
+	if version == 1 {
+		return HashPasswordV1(newPlainPass)
+	}
+
+	if version == 2 {
+		return HashPasswordV2(newPlainPass)
+	}
+
+	if version == 3 {
+		return HashPasswordV3(newPlainPass, langext.Conditional(hastotp, totpsecret, nil))
+	}
+
+	if version == 4 {
+		return HashPasswordV4(newPlainPass, langext.Conditional(hastotp, totpsecret, nil))
+	}
+
+	return "", errors.New("unknown version")
+}
+
 func (ph PassHash) String() string {
 	return string(ph)
 }

dataext/lruMap.go

@@ -19,38 +19,38 @@ import (
 // There are also a bunch of unit tests to ensure that the cache is always in a consistent state
 //
 
-type LRUMap[TData any] struct {
+type LRUMap[TKey comparable, TData any] struct {
 	maxsize int
 	lock    sync.Mutex
 
-	cache map[string]*cacheNode[TData]
+	cache map[TKey]*cacheNode[TKey, TData]
 
-	lfuHead *cacheNode[TData]
-	lfuTail *cacheNode[TData]
+	lfuHead *cacheNode[TKey, TData]
+	lfuTail *cacheNode[TKey, TData]
 }
 
-type cacheNode[TData any] struct {
-	key    string
+type cacheNode[TKey comparable, TData any] struct {
+	key    TKey
 	data   TData
-	parent *cacheNode[TData]
-	child  *cacheNode[TData]
+	parent *cacheNode[TKey, TData]
+	child  *cacheNode[TKey, TData]
 }
 
-func NewLRUMap[TData any](size int) *LRUMap[TData] {
+func NewLRUMap[TKey comparable, TData any](size int) *LRUMap[TKey, TData] {
 	if size <= 2 && size != 0 {
 		panic("Size must be > 2  (or 0)")
 	}
 
-	return &LRUMap[TData]{
+	return &LRUMap[TKey, TData]{
 		maxsize: size,
 		lock:    sync.Mutex{},
-		cache:   make(map[string]*cacheNode[TData], size+1),
+		cache:   make(map[TKey]*cacheNode[TKey, TData], size+1),
 		lfuHead: nil,
 		lfuTail: nil,
 	}
 }
 
-func (c *LRUMap[TData]) Put(key string, value TData) {
+func (c *LRUMap[TKey, TData]) Put(key TKey, value TData) {
 	if c.maxsize == 0 {
 		return // cache disabled
 	}
@@ -68,7 +68,7 @@ func (c *LRUMap[TData]) Put(key string, value TData) {
 	}
 
 	// key does not exist: insert into map and add to top of LFU
-	node = &cacheNode[TData]{
+	node = &cacheNode[TKey, TData]{
 		key:    key,
 		data:   value,
 		parent: nil,
@@ -93,7 +93,7 @@ func (c *LRUMap[TData]) Put(key string, value TData) {
 	}
 }
 
-func (c *LRUMap[TData]) TryGet(key string) (TData, bool) {
+func (c *LRUMap[TKey, TData]) TryGet(key TKey) (TData, bool) {
 	if c.maxsize == 0 {
 		return *new(TData), false // cache disabled
 	}
@@ -109,7 +109,7 @@ func (c *LRUMap[TData]) TryGet(key string) (TData, bool) {
 	return val.data, ok
 }
 
-func (c *LRUMap[TData]) moveNodeToTop(node *cacheNode[TData]) {
+func (c *LRUMap[TKey, TData]) moveNodeToTop(node *cacheNode[TKey, TData]) {
 	// (only called in critical section !)
 
 	if c.lfuHead == node { // fast case
@@ -142,7 +142,7 @@ func (c *LRUMap[TData]) moveNodeToTop(node *cacheNode[TData]) {
 	}
 }
 
-func (c *LRUMap[TData]) Size() int {
+func (c *LRUMap[TKey, TData]) Size() int {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 	return len(c.cache)

langext/bool.go

@@ -15,3 +15,35 @@ func Conditional[T any](v bool, resTrue T, resFalse T) T {
 		return resFalse
 	}
 }
+
+func ConditionalFn00[T any](v bool, resTrue T, resFalse T) T {
+	if v {
+		return resTrue
+	} else {
+		return resFalse
+	}
+}
+
+func ConditionalFn10[T any](v bool, resTrue func() T, resFalse T) T {
+	if v {
+		return resTrue()
+	} else {
+		return resFalse
+	}
+}
+
+func ConditionalFn01[T any](v bool, resTrue T, resFalse func() T) T {
+	if v {
+		return resTrue
+	} else {
+		return resFalse()
+	}
+}
+
+func ConditionalFn11[T any](v bool, resTrue func() T, resFalse func() T) T {
+	if v {
+		return resTrue()
+	} else {
+		return resFalse()
+	}
+}

rext/wrapper.go

@@ -0,0 +1,130 @@
+package rext
+
+import "regexp"
+
+type Regex interface {
+	IsMatch(haystack string) bool
+	MatchFirst(haystack string) (RegexMatch, bool)
+	MatchAll(haystack string) []RegexMatch
+	ReplaceAll(haystack string, repl string, literal bool) string
+	ReplaceAllFunc(haystack string, repl func(string) string) string
+	RemoveAll(haystack string) string
+	GroupCount() int
+}
+
+type regexWrapper struct {
+	rex      *regexp.Regexp
+	subnames []string
+}
+
+type RegexMatch struct {
+	haystack        string
+	submatchesIndex []int
+	subnames        []string
+}
+
+type RegexMatchGroup struct {
+	haystack string
+	start    int
+	end      int
+}
+
+func W(rex *regexp.Regexp) Regex {
+	return &regexWrapper{rex: rex, subnames: rex.SubexpNames()}
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+func (w *regexWrapper) IsMatch(haystack string) bool {
+	return w.rex.MatchString(haystack)
+}
+
+func (w *regexWrapper) MatchFirst(haystack string) (RegexMatch, bool) {
+	res := w.rex.FindStringSubmatchIndex(haystack)
+	if res == nil {
+		return RegexMatch{}, false
+	}
+
+	return RegexMatch{haystack: haystack, submatchesIndex: res, subnames: w.subnames}, true
+}
+
+func (w *regexWrapper) MatchAll(haystack string) []RegexMatch {
+	resarr := w.rex.FindAllStringSubmatchIndex(haystack, -1)
+
+	matches := make([]RegexMatch, 0, len(resarr))
+	for _, res := range resarr {
+		matches = append(matches, RegexMatch{haystack: haystack, submatchesIndex: res, subnames: w.subnames})
+	}
+
+	return matches
+}
+
+func (w *regexWrapper) ReplaceAll(haystack string, repl string, literal bool) string {
+	if literal {
+		// do not expand placeholder aka $1, $2, ...
+		return w.rex.ReplaceAllLiteralString(haystack, repl)
+	} else {
+		return w.rex.ReplaceAllString(haystack, repl)
+	}
+}
+
+func (w *regexWrapper) ReplaceAllFunc(haystack string, repl func(string) string) string {
+	return w.rex.ReplaceAllStringFunc(haystack, repl)
+}
+
+func (w *regexWrapper) RemoveAll(haystack string) string {
+	return w.rex.ReplaceAllLiteralString(haystack, "")
+}
+
+// GroupCount returns the amount of groups in this match, does not count group-0 (whole match)
+func (w *regexWrapper) GroupCount() int {
+	return len(w.subnames) - 1
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+func (m RegexMatch) FullMatch() RegexMatchGroup {
+	return RegexMatchGroup{haystack: m.haystack, start: m.submatchesIndex[0], end: m.submatchesIndex[1]}
+}
+
+// GroupCount returns the amount of groups in this match, does not count group-0 (whole match)
+func (m RegexMatch) GroupCount() int {
+	return len(m.subnames) - 1
+}
+
+// GroupByIndex returns the value of a matched group (group 0 == whole match)
+func (m RegexMatch) GroupByIndex(idx int) RegexMatchGroup {
+	return RegexMatchGroup{haystack: m.haystack, start: m.submatchesIndex[idx*2], end: m.submatchesIndex[idx*2+1]}
+}
+
+// GroupByName returns the value of a matched group (group 0 == whole match)
+func (m RegexMatch) GroupByName(name string) RegexMatchGroup {
+	for idx, subname := range m.subnames {
+		if subname == name {
+			return RegexMatchGroup{haystack: m.haystack, start: m.submatchesIndex[idx*2], end: m.submatchesIndex[idx*2+1]}
+		}
+	}
+	panic("failed to find regex-group by name")
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+func (g RegexMatchGroup) Value() string {
+	return g.haystack[g.start:g.end]
+}
+
+func (g RegexMatchGroup) Start() int {
+	return g.start
+}
+
+func (g RegexMatchGroup) End() int {
+	return g.end
+}
+
+func (g RegexMatchGroup) Range() (int, int) {
+	return g.start, g.end
+}
+
+func (g RegexMatchGroup) Length() int {
+	return g.end - g.start
+}