diff --git a/go.mod b/go.mod
index 60c1dc70..f2d51df0 100644
--- a/go.mod
+++ b/go.mod
@@ -20,7 +20,7 @@ require (
 	github.com/tidwall/rtree v0.0.0-20201027154624-32188eeb08a8 // indirect
 	github.com/toorop/go-dkim v0.0.0-20201103131630-e1cd1a0a5208
 	golang.org/x/crypto v0.0.0-20210415154028-4f45737414dc
-	golang.org/x/text v0.3.4
+	golang.org/x/text v0.3.6
 	gopkg.in/yaml.v2 v2.3.0
 )
 
diff --git a/go.sum b/go.sum
index 04d37623..34eec2d6 100644
--- a/go.sum
+++ b/go.sum
@@ -130,6 +130,8 @@ golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.4 h1:0YWbFKbhXG/wIiuHDSKpS0Iy7FSA+u45VtBMfQcFTTc=
 golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
diff --git a/vendor/golang.org/x/text/cases/icu.go b/vendor/golang.org/x/text/cases/icu.go
index 46530d1e..2dc84b39 100644
--- a/vendor/golang.org/x/text/cases/icu.go
+++ b/vendor/golang.org/x/text/cases/icu.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build icu
 // +build icu
 
 package cases
diff --git a/vendor/golang.org/x/text/cases/tables10.0.0.go b/vendor/golang.org/x/text/cases/tables10.0.0.go
index 5c87950c..ca992310 100644
--- a/vendor/golang.org/x/text/cases/tables10.0.0.go
+++ b/vendor/golang.org/x/text/cases/tables10.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.10 && !go1.13
 // +build go1.10,!go1.13
 
 package cases
diff --git a/vendor/golang.org/x/text/cases/tables11.0.0.go b/vendor/golang.org/x/text/cases/tables11.0.0.go
index 84d27018..b1106b41 100644
--- a/vendor/golang.org/x/text/cases/tables11.0.0.go
+++ b/vendor/golang.org/x/text/cases/tables11.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.13 && !go1.14
 // +build go1.13,!go1.14
 
 package cases
diff --git a/vendor/golang.org/x/text/cases/tables12.0.0.go b/vendor/golang.org/x/text/cases/tables12.0.0.go
index edee17d0..ae7dc240 100644
--- a/vendor/golang.org/x/text/cases/tables12.0.0.go
+++ b/vendor/golang.org/x/text/cases/tables12.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.14 && !go1.16
 // +build go1.14,!go1.16
 
 package cases
diff --git a/vendor/golang.org/x/text/cases/tables13.0.0.go b/vendor/golang.org/x/text/cases/tables13.0.0.go
index 90a2453f..cd874775 100644
--- a/vendor/golang.org/x/text/cases/tables13.0.0.go
+++ b/vendor/golang.org/x/text/cases/tables13.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.16
 // +build go1.16
 
 package cases
diff --git a/vendor/golang.org/x/text/cases/tables9.0.0.go b/vendor/golang.org/x/text/cases/tables9.0.0.go
index 4949fa72..636d5d14 100644
--- a/vendor/golang.org/x/text/cases/tables9.0.0.go
+++ b/vendor/golang.org/x/text/cases/tables9.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build !go1.10
 // +build !go1.10
 
 package cases
diff --git a/vendor/golang.org/x/text/internal/language/language.go b/vendor/golang.org/x/text/internal/language/language.go
index 1e74d1af..f41aedcf 100644
--- a/vendor/golang.org/x/text/internal/language/language.go
+++ b/vendor/golang.org/x/text/internal/language/language.go
@@ -303,9 +303,17 @@ func (t Tag) Extensions() []string {
 // are of the allowed values defined for the Unicode locale extension ('u') in
 // https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
 // TypeForKey will traverse the inheritance chain to get the correct value.
+//
+// If there are multiple types associated with a key, only the first will be
+// returned. If there is no type associated with a key, it returns the empty
+// string.
 func (t Tag) TypeForKey(key string) string {
-	if start, end, _ := t.findTypeForKey(key); end != start {
-		return t.str[start:end]
+	if _, start, end, _ := t.findTypeForKey(key); end != start {
+		s := t.str[start:end]
+		if p := strings.IndexByte(s, '-'); p >= 0 {
+			s = s[:p]
+		}
+		return s
 	}
 	return ""
 }
@@ -329,13 +337,13 @@ func (t Tag) SetTypeForKey(key, value string) (Tag, error) {
 
 	// Remove the setting if value is "".
 	if value == "" {
-		start, end, _ := t.findTypeForKey(key)
-		if start != end {
-			// Remove key tag and leading '-'.
-			start -= 4
-
+		start, sep, end, _ := t.findTypeForKey(key)
+		if start != sep {
 			// Remove a possible empty extension.
-			if (end == len(t.str) || t.str[end+2] == '-') && t.str[start-2] == '-' {
+			switch {
+			case t.str[start-2] != '-': // has previous elements.
+			case end == len(t.str), // end of string
+				end+2 < len(t.str) && t.str[end+2] == '-': // end of extension
 				start -= 2
 			}
 			if start == int(t.pVariant) && end == len(t.str) {
@@ -381,14 +389,14 @@ func (t Tag) SetTypeForKey(key, value string) (Tag, error) {
 		t.str = string(buf[:uStart+len(b)])
 	} else {
 		s := t.str
-		start, end, hasExt := t.findTypeForKey(key)
-		if start == end {
+		start, sep, end, hasExt := t.findTypeForKey(key)
+		if start == sep {
 			if hasExt {
 				b = b[2:]
 			}
-			t.str = fmt.Sprintf("%s-%s%s", s[:start], b, s[end:])
+			t.str = fmt.Sprintf("%s-%s%s", s[:sep], b, s[end:])
 		} else {
-			t.str = fmt.Sprintf("%s%s%s", s[:start], value, s[end:])
+			t.str = fmt.Sprintf("%s-%s%s", s[:start+3], value, s[end:])
 		}
 	}
 	return t, nil
@@ -399,10 +407,10 @@ func (t Tag) SetTypeForKey(key, value string) (Tag, error) {
 // wasn't found. The hasExt return value reports whether an -u extension was present.
 // Note: the extensions are typically very small and are likely to contain
 // only one key-type pair.
-func (t Tag) findTypeForKey(key string) (start, end int, hasExt bool) {
+func (t Tag) findTypeForKey(key string) (start, sep, end int, hasExt bool) {
 	p := int(t.pExt)
 	if len(key) != 2 || p == len(t.str) || p == 0 {
-		return p, p, false
+		return p, p, p, false
 	}
 	s := t.str
 
@@ -410,10 +418,10 @@ func (t Tag) findTypeForKey(key string) (start, end int, hasExt bool) {
 	for p++; s[p] != 'u'; p++ {
 		if s[p] > 'u' {
 			p--
-			return p, p, false
+			return p, p, p, false
 		}
 		if p = nextExtension(s, p); p == len(s) {
-			return len(s), len(s), false
+			return len(s), len(s), len(s), false
 		}
 	}
 	// Proceed to the hyphen following the extension name.
@@ -424,40 +432,28 @@ func (t Tag) findTypeForKey(key string) (start, end int, hasExt bool) {
 
 	// Iterate over keys until we get the end of a section.
 	for {
-		// p points to the hyphen preceding the current token.
-		if p3 := p + 3; s[p3] == '-' {
-			// Found a key.
-			// Check whether we just processed the key that was requested.
-			if curKey == key {
-				return start, p, true
+		end = p
+		for p++; p < len(s) && s[p] != '-'; p++ {
+		}
+		n := p - end - 1
+		if n <= 2 && curKey == key {
+			if sep < end {
+				sep++
 			}
-			// Set to the next key and continue scanning type tokens.
-			curKey = s[p+1 : p3]
+			return start, sep, end, true
+		}
+		switch n {
+		case 0, // invalid string
+			1: // next extension
+			return end, end, end, true
+		case 2:
+			// next key
+			curKey = s[end+1 : p]
 			if curKey > key {
-				return p, p, true
+				return end, end, end, true
 			}
-			// Start of the type token sequence.
-			start = p + 4
-			// A type is at least 3 characters long.
-			p += 7 // 4 + 3
-		} else {
-			// Attribute or type, which is at least 3 characters long.
-			p += 4
-		}
-		// p points past the third character of a type or attribute.
-		max := p + 5 // maximum length of token plus hyphen.
-		if len(s) < max {
-			max = len(s)
-		}
-		for ; p < max && s[p] != '-'; p++ {
-		}
-		// Bail if we have exhausted all tokens or if the next token starts
-		// a new extension.
-		if p == len(s) || s[p+2] == '-' {
-			if curKey == key {
-				return start, p, true
-			}
-			return p, p, true
+			start = end
+			sep = p
 		}
 	}
 }
diff --git a/vendor/golang.org/x/text/internal/language/parse.go b/vendor/golang.org/x/text/internal/language/parse.go
index 2be83e1d..c696fd0b 100644
--- a/vendor/golang.org/x/text/internal/language/parse.go
+++ b/vendor/golang.org/x/text/internal/language/parse.go
@@ -133,14 +133,15 @@ func (s *scanner) resizeRange(oldStart, oldEnd, newSize int) {
 	s.start = oldStart
 	if end := oldStart + newSize; end != oldEnd {
 		diff := end - oldEnd
-		if end < cap(s.b) {
-			b := make([]byte, len(s.b)+diff)
+		var b []byte
+		if n := len(s.b) + diff; n > cap(s.b) {
+			b = make([]byte, n)
 			copy(b, s.b[:oldStart])
-			copy(b[end:], s.b[oldEnd:])
-			s.b = b
 		} else {
-			s.b = append(s.b[end:], s.b[oldEnd:]...)
+			b = s.b[:n]
 		}
+		copy(b[end:], s.b[oldEnd:])
+		s.b = b
 		s.next = end + (s.next - s.end)
 		s.end = end
 	}
@@ -482,7 +483,7 @@ func parseExtensions(scan *scanner) int {
 func parseExtension(scan *scanner) int {
 	start, end := scan.start, scan.end
 	switch scan.token[0] {
-	case 'u':
+	case 'u': // https://www.ietf.org/rfc/rfc6067.txt
 		attrStart := end
 		scan.scan()
 		for last := []byte{}; len(scan.token) > 2; scan.scan() {
@@ -502,27 +503,29 @@ func parseExtension(scan *scanner) int {
 			last = scan.token
 			end = scan.end
 		}
+		// Scan key-type sequences. A key is of length 2 and may be followed
+		// by 0 or more "type" subtags from 3 to the maximum of 8 letters.
 		var last, key []byte
 		for attrEnd := end; len(scan.token) == 2; last = key {
 			key = scan.token
-			keyEnd := scan.end
-			end = scan.acceptMinSize(3)
+			end = scan.end
+			for scan.scan(); end < scan.end && len(scan.token) > 2; scan.scan() {
+				end = scan.end
+			}
 			// TODO: check key value validity
-			if keyEnd == end || bytes.Compare(key, last) != 1 {
+			if bytes.Compare(key, last) != 1 || scan.err != nil {
 				// We have an invalid key or the keys are not sorted.
 				// Start scanning keys from scratch and reorder.
 				p := attrEnd + 1
 				scan.next = p
 				keys := [][]byte{}
 				for scan.scan(); len(scan.token) == 2; {
-					keyStart, keyEnd := scan.start, scan.end
-					end = scan.acceptMinSize(3)
-					if keyEnd != end {
-						keys = append(keys, scan.b[keyStart:end])
-					} else {
-						scan.setError(ErrSyntax)
-						end = keyStart
+					keyStart := scan.start
+					end = scan.end
+					for scan.scan(); end < scan.end && len(scan.token) > 2; scan.scan() {
+						end = scan.end
 					}
+					keys = append(keys, scan.b[keyStart:end])
 				}
 				sort.Stable(bytesSort{keys, 2})
 				if n := len(keys); n > 0 {
@@ -546,7 +549,7 @@ func parseExtension(scan *scanner) int {
 				break
 			}
 		}
-	case 't':
+	case 't': // https://www.ietf.org/rfc/rfc6497.txt
 		scan.scan()
 		if n := len(scan.token); n >= 2 && n <= 3 && isAlpha(scan.token[1]) {
 			_, end = parseTag(scan)
diff --git a/vendor/golang.org/x/text/language/go1_1.go b/vendor/golang.org/x/text/language/go1_1.go
index 380f4c09..c7435583 100644
--- a/vendor/golang.org/x/text/language/go1_1.go
+++ b/vendor/golang.org/x/text/language/go1_1.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !go1.2
 // +build !go1.2
 
 package language
diff --git a/vendor/golang.org/x/text/language/go1_2.go b/vendor/golang.org/x/text/language/go1_2.go
index 38268c57..77aaaa29 100644
--- a/vendor/golang.org/x/text/language/go1_2.go
+++ b/vendor/golang.org/x/text/language/go1_2.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.2
 // +build go1.2
 
 package language
diff --git a/vendor/golang.org/x/text/language/language.go b/vendor/golang.org/x/text/language/language.go
index abfa17f6..289b3a36 100644
--- a/vendor/golang.org/x/text/language/language.go
+++ b/vendor/golang.org/x/text/language/language.go
@@ -412,6 +412,10 @@ func (t Tag) Extensions() []Extension {
 // are of the allowed values defined for the Unicode locale extension ('u') in
 // https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
 // TypeForKey will traverse the inheritance chain to get the correct value.
+//
+// If there are multiple types associated with a key, only the first will be
+// returned. If there is no type associated with a key, it returns the empty
+// string.
 func (t Tag) TypeForKey(key string) string {
 	if !compact.Tag(t).MayHaveExtensions() {
 		if key != "rg" && key != "va" {
diff --git a/vendor/golang.org/x/text/language/tables.go b/vendor/golang.org/x/text/language/tables.go
index 87e58a02..96b57f61 100644
--- a/vendor/golang.org/x/text/language/tables.go
+++ b/vendor/golang.org/x/text/language/tables.go
@@ -47,7 +47,7 @@ const (
 	_Zzzz = 251
 )
 
-var regionToGroups = []uint8{ // 357 elements
+var regionToGroups = []uint8{ // 358 elements
 	// Entry 0 - 3F
 	0x00, 0x00, 0x00, 0x04, 0x04, 0x00, 0x00, 0x04,
 	0x00, 0x00, 0x00, 0x00, 0x04, 0x04, 0x04, 0x00,
@@ -98,8 +98,8 @@ var regionToGroups = []uint8{ // 357 elements
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-	0x00, 0x00, 0x00, 0x00, 0x00,
-} // Size: 381 bytes
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+} // Size: 382 bytes
 
 var paradigmLocales = [][3]uint16{ // 3 elements
 	0: [3]uint16{0x139, 0x0, 0x7b},
@@ -295,4 +295,4 @@ var matchRegion = []regionIntelligibility{ // 15 elements
 	14: {lang: 0x529, script: 0x3c, group: 0x80, distance: 0x5},
 } // Size: 114 bytes
 
-// Total table size 1471 bytes (1KiB); checksum: 4CB1CD46
+// Total table size 1472 bytes (1KiB); checksum: F86C669
diff --git a/vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go b/vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go
index e4c62289..8a7392c4 100644
--- a/vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go
+++ b/vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.10
 // +build go1.10
 
 package bidirule
diff --git a/vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go b/vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go
index 02b9e1e9..bb0a9200 100644
--- a/vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go
+++ b/vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !go1.10
 // +build !go1.10
 
 package bidirule
diff --git a/vendor/golang.org/x/text/secure/precis/tables10.0.0.go b/vendor/golang.org/x/text/secure/precis/tables10.0.0.go
index 362d2729..81647495 100644
--- a/vendor/golang.org/x/text/secure/precis/tables10.0.0.go
+++ b/vendor/golang.org/x/text/secure/precis/tables10.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.10 && !go1.13
 // +build go1.10,!go1.13
 
 package precis
diff --git a/vendor/golang.org/x/text/secure/precis/tables11.0.0.go b/vendor/golang.org/x/text/secure/precis/tables11.0.0.go
index 0db5a9e7..a40e55d6 100644
--- a/vendor/golang.org/x/text/secure/precis/tables11.0.0.go
+++ b/vendor/golang.org/x/text/secure/precis/tables11.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.13 && !go1.14
 // +build go1.13,!go1.14
 
 package precis
diff --git a/vendor/golang.org/x/text/secure/precis/tables12.0.0.go b/vendor/golang.org/x/text/secure/precis/tables12.0.0.go
index a2392892..254bbc79 100644
--- a/vendor/golang.org/x/text/secure/precis/tables12.0.0.go
+++ b/vendor/golang.org/x/text/secure/precis/tables12.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.14 && !go1.16
 // +build go1.14,!go1.16
 
 package precis
diff --git a/vendor/golang.org/x/text/secure/precis/tables13.0.0.go b/vendor/golang.org/x/text/secure/precis/tables13.0.0.go
index e3ddd730..aad68b35 100644
--- a/vendor/golang.org/x/text/secure/precis/tables13.0.0.go
+++ b/vendor/golang.org/x/text/secure/precis/tables13.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.16
 // +build go1.16
 
 package precis
diff --git a/vendor/golang.org/x/text/secure/precis/tables9.0.0.go b/vendor/golang.org/x/text/secure/precis/tables9.0.0.go
index dacaf6a4..2292b7cb 100644
--- a/vendor/golang.org/x/text/secure/precis/tables9.0.0.go
+++ b/vendor/golang.org/x/text/secure/precis/tables9.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build !go1.10
 // +build !go1.10
 
 package precis
diff --git a/vendor/golang.org/x/text/unicode/bidi/bidi.go b/vendor/golang.org/x/text/unicode/bidi/bidi.go
index e8edc54c..fd057601 100644
--- a/vendor/golang.org/x/text/unicode/bidi/bidi.go
+++ b/vendor/golang.org/x/text/unicode/bidi/bidi.go
@@ -12,15 +12,14 @@
 // and without notice.
 package bidi // import "golang.org/x/text/unicode/bidi"
 
-// TODO:
-// The following functionality would not be hard to implement, but hinges on
-// the definition of a Segmenter interface. For now this is up to the user.
-// - Iterate over paragraphs
-// - Segmenter to iterate over runs directly from a given text.
-// Also:
+// TODO
 // - Transformer for reordering?
 // - Transformer (validator, really) for Bidi Rule.
 
+import (
+	"bytes"
+)
+
 // This API tries to avoid dealing with embedding levels for now. Under the hood
 // these will be computed, but the question is to which extent the user should
 // know they exist. We should at some point allow the user to specify an
@@ -49,7 +48,9 @@ const (
 	Neutral
 )
 
-type options struct{}
+type options struct {
+	defaultDirection Direction
+}
 
 // An Option is an option for Bidi processing.
 type Option func(*options)
@@ -66,12 +67,62 @@ type Option func(*options)
 // DefaultDirection sets the default direction for a Paragraph. The direction is
 // overridden if the text contains directional characters.
 func DefaultDirection(d Direction) Option {
-	panic("unimplemented")
+	return func(opts *options) {
+		opts.defaultDirection = d
+	}
 }
 
 // A Paragraph holds a single Paragraph for Bidi processing.
 type Paragraph struct {
-	// buffers
+	p          []byte
+	o          Ordering
+	opts       []Option
+	types      []Class
+	pairTypes  []bracketType
+	pairValues []rune
+	runes      []rune
+	options    options
+}
+
+// Initialize the p.pairTypes, p.pairValues and p.types from the input previously
+// set by p.SetBytes() or p.SetString(). Also limit the input up to (and including) a paragraph
+// separator (bidi class B).
+//
+// The function p.Order() needs these values to be set, so this preparation could be postponed.
+// But since the SetBytes and SetStrings functions return the length of the input up to the paragraph
+// separator, the whole input needs to be processed anyway and should not be done twice.
+//
+// The function has the same return values as SetBytes() / SetString()
+func (p *Paragraph) prepareInput() (n int, err error) {
+	p.runes = bytes.Runes(p.p)
+	bytecount := 0
+	// clear slices from previous SetString or SetBytes
+	p.pairTypes = nil
+	p.pairValues = nil
+	p.types = nil
+
+	for _, r := range p.runes {
+		props, i := LookupRune(r)
+		bytecount += i
+		cls := props.Class()
+		if cls == B {
+			return bytecount, nil
+		}
+		p.types = append(p.types, cls)
+		if props.IsOpeningBracket() {
+			p.pairTypes = append(p.pairTypes, bpOpen)
+			p.pairValues = append(p.pairValues, r)
+		} else if props.IsBracket() {
+			// this must be a closing bracket,
+			// since IsOpeningBracket is not true
+			p.pairTypes = append(p.pairTypes, bpClose)
+			p.pairValues = append(p.pairValues, r)
+		} else {
+			p.pairTypes = append(p.pairTypes, bpNone)
+			p.pairValues = append(p.pairValues, 0)
+		}
+	}
+	return bytecount, nil
 }
 
 // SetBytes configures p for the given paragraph text. It replaces text
@@ -80,70 +131,150 @@ type Paragraph struct {
 // consumed from b including this separator. Error may be non-nil if options are
 // given.
 func (p *Paragraph) SetBytes(b []byte, opts ...Option) (n int, err error) {
-	panic("unimplemented")
+	p.p = b
+	p.opts = opts
+	return p.prepareInput()
 }
 
-// SetString configures p for the given paragraph text. It replaces text
-// previously set by SetBytes or SetString. If b contains a paragraph separator
+// SetString configures s for the given paragraph text. It replaces text
+// previously set by SetBytes or SetString. If s contains a paragraph separator
 // it will only process the first paragraph and report the number of bytes
-// consumed from b including this separator. Error may be non-nil if options are
+// consumed from s including this separator. Error may be non-nil if options are
 // given.
 func (p *Paragraph) SetString(s string, opts ...Option) (n int, err error) {
-	panic("unimplemented")
+	p.p = []byte(s)
+	p.opts = opts
+	return p.prepareInput()
 }
 
 // IsLeftToRight reports whether the principle direction of rendering for this
 // paragraphs is left-to-right. If this returns false, the principle direction
 // of rendering is right-to-left.
 func (p *Paragraph) IsLeftToRight() bool {
-	panic("unimplemented")
+	return p.Direction() == LeftToRight
 }
 
 // Direction returns the direction of the text of this paragraph.
 //
 // The direction may be LeftToRight, RightToLeft, Mixed, or Neutral.
 func (p *Paragraph) Direction() Direction {
-	panic("unimplemented")
+	return p.o.Direction()
 }
 
+// TODO: what happens if the position is > len(input)? This should return an error.
+
 // RunAt reports the Run at the given position of the input text.
 //
 // This method can be used for computing line breaks on paragraphs.
 func (p *Paragraph) RunAt(pos int) Run {
-	panic("unimplemented")
+	c := 0
+	runNumber := 0
+	for i, r := range p.o.runes {
+		c += len(r)
+		if pos < c {
+			runNumber = i
+		}
+	}
+	return p.o.Run(runNumber)
+}
+
+func calculateOrdering(levels []level, runes []rune) Ordering {
+	var curDir Direction
+
+	prevDir := Neutral
+	prevI := 0
+
+	o := Ordering{}
+	// lvl = 0,2,4,...: left to right
+	// lvl = 1,3,5,...: right to left
+	for i, lvl := range levels {
+		if lvl%2 == 0 {
+			curDir = LeftToRight
+		} else {
+			curDir = RightToLeft
+		}
+		if curDir != prevDir {
+			if i > 0 {
+				o.runes = append(o.runes, runes[prevI:i])
+				o.directions = append(o.directions, prevDir)
+				o.startpos = append(o.startpos, prevI)
+			}
+			prevI = i
+			prevDir = curDir
+		}
+	}
+	o.runes = append(o.runes, runes[prevI:])
+	o.directions = append(o.directions, prevDir)
+	o.startpos = append(o.startpos, prevI)
+	return o
 }
 
 // Order computes the visual ordering of all the runs in a Paragraph.
 func (p *Paragraph) Order() (Ordering, error) {
-	panic("unimplemented")
+	if len(p.types) == 0 {
+		return Ordering{}, nil
+	}
+
+	for _, fn := range p.opts {
+		fn(&p.options)
+	}
+	lvl := level(-1)
+	if p.options.defaultDirection == RightToLeft {
+		lvl = 1
+	}
+	para, err := newParagraph(p.types, p.pairTypes, p.pairValues, lvl)
+	if err != nil {
+		return Ordering{}, err
+	}
+
+	levels := para.getLevels([]int{len(p.types)})
+
+	p.o = calculateOrdering(levels, p.runes)
+	return p.o, nil
 }
 
 // Line computes the visual ordering of runs for a single line starting and
 // ending at the given positions in the original text.
 func (p *Paragraph) Line(start, end int) (Ordering, error) {
-	panic("unimplemented")
+	lineTypes := p.types[start:end]
+	para, err := newParagraph(lineTypes, p.pairTypes[start:end], p.pairValues[start:end], -1)
+	if err != nil {
+		return Ordering{}, err
+	}
+	levels := para.getLevels([]int{len(lineTypes)})
+	o := calculateOrdering(levels, p.runes[start:end])
+	return o, nil
 }
 
 // An Ordering holds the computed visual order of runs of a Paragraph. Calling
 // SetBytes or SetString on the originating Paragraph invalidates an Ordering.
 // The methods of an Ordering should only be called by one goroutine at a time.
-type Ordering struct{}
+type Ordering struct {
+	runes      [][]rune
+	directions []Direction
+	startpos   []int
+}
 
 // Direction reports the directionality of the runs.
 //
 // The direction may be LeftToRight, RightToLeft, Mixed, or Neutral.
 func (o *Ordering) Direction() Direction {
-	panic("unimplemented")
+	return o.directions[0]
 }
 
 // NumRuns returns the number of runs.
 func (o *Ordering) NumRuns() int {
-	panic("unimplemented")
+	return len(o.runes)
 }
 
 // Run returns the ith run within the ordering.
 func (o *Ordering) Run(i int) Run {
-	panic("unimplemented")
+	r := Run{
+		runes:     o.runes[i],
+		direction: o.directions[i],
+		startpos:  o.startpos[i],
+	}
+	return r
 }
 
 // TODO: perhaps with options.
@@ -155,16 +286,19 @@ func (o *Ordering) Run(i int) Run {
 
 // A Run is a continuous sequence of characters of a single direction.
 type Run struct {
+	runes     []rune
+	direction Direction
+	startpos  int
 }
 
 // String returns the text of the run in its original order.
 func (r *Run) String() string {
-	panic("unimplemented")
+	return string(r.runes)
 }
 
 // Bytes returns the text of the run in its original order.
 func (r *Run) Bytes() []byte {
-	panic("unimplemented")
+	return []byte(r.String())
 }
 
 // TODO: methods for
@@ -174,25 +308,52 @@ func (r *Run) Bytes() []byte {
 
 // Direction reports the direction of the run.
 func (r *Run) Direction() Direction {
-	panic("unimplemented")
+	return r.direction
 }
 
-// Position of the Run within the text passed to SetBytes or SetString of the
+// Pos returns the position of the Run within the text passed to SetBytes or SetString of the
 // originating Paragraph value.
 func (r *Run) Pos() (start, end int) {
-	panic("unimplemented")
+	return r.startpos, r.startpos + len(r.runes) - 1
 }
 
 // AppendReverse reverses the order of characters of in, appends them to out,
 // and returns the result. Modifiers will still follow the runes they modify.
 // Brackets are replaced with their counterparts.
 func AppendReverse(out, in []byte) []byte {
-	panic("unimplemented")
+	ret := make([]byte, len(in)+len(out))
+	copy(ret, out)
+	inRunes := bytes.Runes(in)
+
+	for i, r := range inRunes {
+		prop, _ := LookupRune(r)
+		if prop.IsBracket() {
+			inRunes[i] = prop.reverseBracket(r)
+		}
+	}
+
+	for i, j := 0, len(inRunes)-1; i < j; i, j = i+1, j-1 {
+		inRunes[i], inRunes[j] = inRunes[j], inRunes[i]
+	}
+	copy(ret[len(out):], string(inRunes))
+
+	return ret
 }
 
 // ReverseString reverses the order of characters in s and returns a new string.
 // Modifiers will still follow the runes they modify. Brackets are replaced with
 // their counterparts.
 func ReverseString(s string) string {
-	panic("unimplemented")
+	input := []rune(s)
+	li := len(input)
+	ret := make([]rune, li)
+	for i, r := range input {
+		prop, _ := LookupRune(r)
+		if prop.IsBracket() {
+			ret[li-i-1] = prop.reverseBracket(r)
+		} else {
+			ret[li-i-1] = r
+		}
+	}
+	return string(ret)
 }
diff --git a/vendor/golang.org/x/text/unicode/bidi/core.go b/vendor/golang.org/x/text/unicode/bidi/core.go
index 50deb660..e4c08110 100644
--- a/vendor/golang.org/x/text/unicode/bidi/core.go
+++ b/vendor/golang.org/x/text/unicode/bidi/core.go
@@ -4,7 +4,10 @@
 
 package bidi
 
-import "log"
+import (
+	"fmt"
+	"log"
+)
 
 // This implementation is a port based on the reference implementation found at:
 // https://www.unicode.org/Public/PROGRAMS/BidiReferenceJava/
@@ -97,13 +100,20 @@ type paragraph struct {
 // rune (suggested is the rune of the open bracket for opening and matching
 // close brackets, after normalization). The embedding levels are optional, but
 // may be supplied to encode embedding levels of styled text.
-//
-// TODO: return an error.
-func newParagraph(types []Class, pairTypes []bracketType, pairValues []rune, levels level) *paragraph {
-	validateTypes(types)
-	validatePbTypes(pairTypes)
-	validatePbValues(pairValues, pairTypes)
-	validateParagraphEmbeddingLevel(levels)
+func newParagraph(types []Class, pairTypes []bracketType, pairValues []rune, levels level) (*paragraph, error) {
+	var err error
+	if err = validateTypes(types); err != nil {
+		return nil, err
+	}
+	if err = validatePbTypes(pairTypes); err != nil {
+		return nil, err
+	}
+	if err = validatePbValues(pairValues, pairTypes); err != nil {
+		return nil, err
+	}
+	if err = validateParagraphEmbeddingLevel(levels); err != nil {
+		return nil, err
+	}
 
 	p := &paragraph{
 		initialTypes:   append([]Class(nil), types...),
@@ -115,7 +125,7 @@ func newParagraph(types []Class, pairTypes []bracketType, pairValues []rune, lev
 		resultTypes: append([]Class(nil), types...),
 	}
 	p.run()
-	return p
+	return p, nil
 }
 
 func (p *paragraph) Len() int { return len(p.initialTypes) }
@@ -1001,58 +1011,61 @@ func typeForLevel(level level) Class {
 	return R
 }
 
-// TODO: change validation to not panic
-
-func validateTypes(types []Class) {
+func validateTypes(types []Class) error {
 	if len(types) == 0 {
-		log.Panic("types is null")
+		return fmt.Errorf("types is null")
 	}
 	for i, t := range types[:len(types)-1] {
 		if t == B {
-			log.Panicf("B type before end of paragraph at index: %d", i)
+			return fmt.Errorf("B type before end of paragraph at index: %d", i)
 		}
 	}
+	return nil
 }
 
-func validateParagraphEmbeddingLevel(embeddingLevel level) {
+func validateParagraphEmbeddingLevel(embeddingLevel level) error {
 	if embeddingLevel != implicitLevel &&
 		embeddingLevel != 0 &&
 		embeddingLevel != 1 {
-		log.Panicf("illegal paragraph embedding level: %d", embeddingLevel)
+		return fmt.Errorf("illegal paragraph embedding level: %d", embeddingLevel)
 	}
+	return nil
 }
 
-func validateLineBreaks(linebreaks []int, textLength int) {
+func validateLineBreaks(linebreaks []int, textLength int) error {
 	prev := 0
 	for i, next := range linebreaks {
 		if next <= prev {
-			log.Panicf("bad linebreak: %d at index: %d", next, i)
+			return fmt.Errorf("bad linebreak: %d at index: %d", next, i)
 		}
 		prev = next
 	}
 	if prev != textLength {
-		log.Panicf("last linebreak was %d, want %d", prev, textLength)
+		return fmt.Errorf("last linebreak was %d, want %d", prev, textLength)
 	}
+	return nil
 }
 
-func validatePbTypes(pairTypes []bracketType) {
+func validatePbTypes(pairTypes []bracketType) error {
 	if len(pairTypes) == 0 {
-		log.Panic("pairTypes is null")
+		return fmt.Errorf("pairTypes is null")
 	}
 	for i, pt := range pairTypes {
 		switch pt {
 		case bpNone, bpOpen, bpClose:
 		default:
-			log.Panicf("illegal pairType value at %d: %v", i, pairTypes[i])
+			return fmt.Errorf("illegal pairType value at %d: %v", i, pairTypes[i])
 		}
 	}
+	return nil
 }
 
-func validatePbValues(pairValues []rune, pairTypes []bracketType) {
+func validatePbValues(pairValues []rune, pairTypes []bracketType) error {
 	if pairValues == nil {
-		log.Panic("pairValues is null")
+		return fmt.Errorf("pairValues is null")
 	}
 	if len(pairTypes) != len(pairValues) {
-		log.Panic("pairTypes is different length from pairValues")
+		return fmt.Errorf("pairTypes is different length from pairValues")
 	}
+	return nil
 }
diff --git a/vendor/golang.org/x/text/unicode/bidi/tables10.0.0.go b/vendor/golang.org/x/text/unicode/bidi/tables10.0.0.go
index d8c94e1b..42fa8d72 100644
--- a/vendor/golang.org/x/text/unicode/bidi/tables10.0.0.go
+++ b/vendor/golang.org/x/text/unicode/bidi/tables10.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.10 && !go1.13
 // +build go1.10,!go1.13
 
 package bidi
diff --git a/vendor/golang.org/x/text/unicode/bidi/tables11.0.0.go b/vendor/golang.org/x/text/unicode/bidi/tables11.0.0.go
index 16b11db5..56a0e1ea 100644
--- a/vendor/golang.org/x/text/unicode/bidi/tables11.0.0.go
+++ b/vendor/golang.org/x/text/unicode/bidi/tables11.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.13 && !go1.14
 // +build go1.13,!go1.14
 
 package bidi
diff --git a/vendor/golang.org/x/text/unicode/bidi/tables12.0.0.go b/vendor/golang.org/x/text/unicode/bidi/tables12.0.0.go
index 647f2d42..baacf32b 100644
--- a/vendor/golang.org/x/text/unicode/bidi/tables12.0.0.go
+++ b/vendor/golang.org/x/text/unicode/bidi/tables12.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.14 && !go1.16
 // +build go1.14,!go1.16
 
 package bidi
diff --git a/vendor/golang.org/x/text/unicode/bidi/tables13.0.0.go b/vendor/golang.org/x/text/unicode/bidi/tables13.0.0.go
index c937d097..f248effa 100644
--- a/vendor/golang.org/x/text/unicode/bidi/tables13.0.0.go
+++ b/vendor/golang.org/x/text/unicode/bidi/tables13.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.16
 // +build go1.16
 
 package bidi
diff --git a/vendor/golang.org/x/text/unicode/bidi/tables9.0.0.go b/vendor/golang.org/x/text/unicode/bidi/tables9.0.0.go
index 0ca0193e..f517fdb2 100644
--- a/vendor/golang.org/x/text/unicode/bidi/tables9.0.0.go
+++ b/vendor/golang.org/x/text/unicode/bidi/tables9.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build !go1.10
 // +build !go1.10
 
 package bidi
diff --git a/vendor/golang.org/x/text/unicode/norm/tables10.0.0.go b/vendor/golang.org/x/text/unicode/norm/tables10.0.0.go
index 26fbd55a..f5a07882 100644
--- a/vendor/golang.org/x/text/unicode/norm/tables10.0.0.go
+++ b/vendor/golang.org/x/text/unicode/norm/tables10.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.10 && !go1.13
 // +build go1.10,!go1.13
 
 package norm
diff --git a/vendor/golang.org/x/text/unicode/norm/tables11.0.0.go b/vendor/golang.org/x/text/unicode/norm/tables11.0.0.go
index 2c58f09b..cb7239c4 100644
--- a/vendor/golang.org/x/text/unicode/norm/tables11.0.0.go
+++ b/vendor/golang.org/x/text/unicode/norm/tables11.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.13 && !go1.14
 // +build go1.13,!go1.14
 
 package norm
diff --git a/vendor/golang.org/x/text/unicode/norm/tables12.0.0.go b/vendor/golang.org/x/text/unicode/norm/tables12.0.0.go
index 7e1ae096..11b27330 100644
--- a/vendor/golang.org/x/text/unicode/norm/tables12.0.0.go
+++ b/vendor/golang.org/x/text/unicode/norm/tables12.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.14 && !go1.16
 // +build go1.14,!go1.16
 
 package norm
diff --git a/vendor/golang.org/x/text/unicode/norm/tables13.0.0.go b/vendor/golang.org/x/text/unicode/norm/tables13.0.0.go
index 9ea1b421..96a130d3 100644
--- a/vendor/golang.org/x/text/unicode/norm/tables13.0.0.go
+++ b/vendor/golang.org/x/text/unicode/norm/tables13.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.16
 // +build go1.16
 
 package norm
diff --git a/vendor/golang.org/x/text/unicode/norm/tables9.0.0.go b/vendor/golang.org/x/text/unicode/norm/tables9.0.0.go
index 94290692..0175eae5 100644
--- a/vendor/golang.org/x/text/unicode/norm/tables9.0.0.go
+++ b/vendor/golang.org/x/text/unicode/norm/tables9.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build !go1.10
 // +build !go1.10
 
 package norm
diff --git a/vendor/golang.org/x/text/width/tables10.0.0.go b/vendor/golang.org/x/text/width/tables10.0.0.go
index decb8e48..186b1d4e 100644
--- a/vendor/golang.org/x/text/width/tables10.0.0.go
+++ b/vendor/golang.org/x/text/width/tables10.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.10 && !go1.13
 // +build go1.10,!go1.13
 
 package width
diff --git a/vendor/golang.org/x/text/width/tables11.0.0.go b/vendor/golang.org/x/text/width/tables11.0.0.go
index 3c75e428..990f7622 100644
--- a/vendor/golang.org/x/text/width/tables11.0.0.go
+++ b/vendor/golang.org/x/text/width/tables11.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.13 && !go1.14
 // +build go1.13,!go1.14
 
 package width
diff --git a/vendor/golang.org/x/text/width/tables12.0.0.go b/vendor/golang.org/x/text/width/tables12.0.0.go
index 543942b9..85296297 100644
--- a/vendor/golang.org/x/text/width/tables12.0.0.go
+++ b/vendor/golang.org/x/text/width/tables12.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.14 && !go1.16
 // +build go1.14,!go1.16
 
 package width
diff --git a/vendor/golang.org/x/text/width/tables13.0.0.go b/vendor/golang.org/x/text/width/tables13.0.0.go
index 804264ca..bac3f1ae 100644
--- a/vendor/golang.org/x/text/width/tables13.0.0.go
+++ b/vendor/golang.org/x/text/width/tables13.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build go1.16
 // +build go1.16
 
 package width
diff --git a/vendor/golang.org/x/text/width/tables9.0.0.go b/vendor/golang.org/x/text/width/tables9.0.0.go
index 7069e263..b3db84f6 100644
--- a/vendor/golang.org/x/text/width/tables9.0.0.go
+++ b/vendor/golang.org/x/text/width/tables9.0.0.go
@@ -1,5 +1,6 @@
 // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
 
+//go:build !go1.10
 // +build !go1.10
 
 package width
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 03076302..91cdabc4 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -77,7 +77,7 @@ golang.org/x/sys/unix
 golang.org/x/sys/windows
 # golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1
 golang.org/x/term
-# golang.org/x/text v0.3.4
+# golang.org/x/text v0.3.6
 ## explicit
 golang.org/x/text/cases
 golang.org/x/text/internal