vendor: added vendor packages necessary for the swarm-network-rewrite merge (#16792)

* vendor: added vendor packages necessary for the swarm-network-rewrite merge into ethereum master

* vendor: removed multihash deps

vendor/github.com/naoina/toml/encode.go

@@ -61,20 +61,26 @@ func (cfg *Config) NewEncoder(w io.Writer) *Encoder {
 // Encode writes the TOML of v to the stream.
 // See the documentation for Marshal for details about the conversion of Go values to TOML.
 func (e *Encoder) Encode(v interface{}) error {
-	rv := reflect.ValueOf(v)
+	var (
+		buf = &tableBuf{typ: ast.TableTypeNormal}
+		rv  = reflect.ValueOf(v)
+		err error
+	)
+
 	for rv.Kind() == reflect.Ptr {
 		if rv.IsNil() {
 			return &marshalNilError{rv.Type()}
 		}
 		rv = rv.Elem()
 	}
-	buf := &tableBuf{typ: ast.TableTypeNormal}
-	var err error
+
 	switch rv.Kind() {
 	case reflect.Struct:
 		err = buf.structFields(e.cfg, rv)
 	case reflect.Map:
 		err = buf.mapFields(e.cfg, rv)
+	case reflect.Interface:
+		return e.Encode(rv.Interface())
 	default:
 		err = &marshalTableError{rv.Type()}
 	}

vendor/github.com/naoina/toml/parse.go

@@ -97,6 +97,7 @@ type toml struct {
 	currentTable *ast.Table
 	s            string
 	key          string
+	tableKeys    []string
 	val          ast.Value
 	arr          *array
 	stack        []*stack
@@ -180,12 +181,12 @@ func (p *tomlParser) SetArray(begin, end int) {
 }
 
 func (p *toml) SetTable(buf []rune, begin, end int) {
-	p.setTable(p.table, buf, begin, end)
+	rawName := string(buf[begin:end])
+	p.setTable(p.table, rawName, p.tableKeys)
+	p.tableKeys = nil
 }
 
-func (p *toml) setTable(parent *ast.Table, buf []rune, begin, end int) {
-	name := string(buf[begin:end])
-	names := splitTableKey(name)
+func (p *toml) setTable(parent *ast.Table, name string, names []string) {
 	parent, err := p.lookupTable(parent, names[:len(names)-1])
 	if err != nil {
 		p.Error(err)
@@ -230,12 +231,12 @@ func (p *tomlParser) SetTableString(begin, end int) {
 }
 
 func (p *toml) SetArrayTable(buf []rune, begin, end int) {
-	p.setArrayTable(p.table, buf, begin, end)
+	rawName := string(buf[begin:end])
+	p.setArrayTable(p.table, rawName, p.tableKeys)
+	p.tableKeys = nil
 }
 
-func (p *toml) setArrayTable(parent *ast.Table, buf []rune, begin, end int) {
-	name := string(buf[begin:end])
-	names := splitTableKey(name)
+func (p *toml) setArrayTable(parent *ast.Table, name string, names []string) {
 	parent, err := p.lookupTable(parent, names[:len(names)-1])
 	if err != nil {
 		p.Error(err)
@@ -260,11 +261,11 @@ func (p *toml) setArrayTable(parent *ast.Table, buf []rune, begin, end int) {
 func (p *toml) StartInlineTable() {
 	p.skip = false
 	p.stack = append(p.stack, &stack{p.key, p.currentTable})
-	buf := []rune(p.key)
+	names := []string{p.key}
 	if p.arr == nil {
-		p.setTable(p.currentTable, buf, 0, len(buf))
+		p.setTable(p.currentTable, names[0], names)
 	} else {
-		p.setArrayTable(p.currentTable, buf, 0, len(buf))
+		p.setArrayTable(p.currentTable, names[0], names)
 	}
 }
 
@@ -282,6 +283,13 @@ func (p *toml) AddLineCount(i int) {
 
 func (p *toml) SetKey(buf []rune, begin, end int) {
 	p.key = string(buf[begin:end])
+	if len(p.key) > 0 && p.key[0] == '"' {
+		p.key = p.unquote(p.key)
+	}
+}
+
+func (p *toml) AddTableKey() {
+	p.tableKeys = append(p.tableKeys, p.key)
 }
 
 func (p *toml) AddKeyValue() {
@@ -352,25 +360,3 @@ func (p *toml) lookupTable(t *ast.Table, keys []string) (*ast.Table, error) {
 	}
 	return t, nil
 }
-
-func splitTableKey(tk string) []string {
-	key := make([]byte, 0, 1)
-	keys := make([]string, 0, 1)
-	inQuote := false
-	for i := 0; i < len(tk); i++ {
-		k := tk[i]
-		switch {
-		case k == tableSeparator && !inQuote:
-			keys = append(keys, string(key))
-			key = key[:0] // reuse buffer.
-		case k == '"':
-			inQuote = !inQuote
-		case (k == ' ' || k == '\t') && !inQuote:
-			// skip.
-		default:
-			key = append(key, k)
-		}
-	}
-	keys = append(keys, string(key))
-	return keys
-}

vendor/github.com/naoina/toml/parse.peg

@@ -29,7 +29,7 @@ key <- bareKey / quotedKey
 
 bareKey <- <[0-9A-Za-z\-_]+> { p.SetKey(p.buffer, begin, end) }
 
-quotedKey <- '"' <basicChar+> '"' { p.SetKey(p.buffer, begin-1, end+1) }
+quotedKey <- < '"' basicChar* '"' > { p.SetKey(p.buffer, begin, end) }
 
 val <- (
     <datetime>    { p.SetTime(begin, end) }
@@ -55,7 +55,9 @@ inlineTable <- (
 
 inlineTableKeyValues <- (keyval inlineTableValSep?)*
 
-tableKey <- key (tableKeySep key)*
+tableKey <- tableKeyComp (tableKeySep tableKeyComp)*
+
+tableKeyComp <- key { p.AddTableKey() }
 
 tableKeySep <- ws '.' ws
 
@@ -117,7 +119,7 @@ timeNumoffset <- [\-+] timeHour ':' timeMinute
 timeOffset <- 'Z' / timeNumoffset
 partialTime <- timeHour ':' timeMinute ':' timeSecond timeSecfrac?
 fullDate <- dateFullYear '-' dateMonth '-' dateMDay
-fullTime <- partialTime timeOffset
+fullTime <- partialTime timeOffset?
 datetime <- (fullDate ('T' fullTime)?) / partialTime
 
 digit <- [0-9]

vendor/golang.org/x/net/idna/punycode.go

+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package idna
+
+// This file implements the Punycode algorithm from RFC 3492.
+
+import (
+	"math"
+	"strings"
+	"unicode/utf8"
+)
+
+// These parameter values are specified in section 5.
+//
+// All computation is done with int32s, so that overflow behavior is identical
+// regardless of whether int is 32-bit or 64-bit.
+const (
+	base        int32 = 36
+	damp        int32 = 700
+	initialBias int32 = 72
+	initialN    int32 = 128
+	skew        int32 = 38
+	tmax        int32 = 26
+	tmin        int32 = 1
+)
+
+func punyError(s string) error { return &labelError{s, "A3"} }
+
+// decode decodes a string as specified in section 6.2.
+func decode(encoded string) (string, error) {
+	if encoded == "" {
+		return "", nil
+	}
+	pos := 1 + strings.LastIndex(encoded, "-")
+	if pos == 1 {
+		return "", punyError(encoded)
+	}
+	if pos == len(encoded) {
+		return encoded[:len(encoded)-1], nil
+	}
+	output := make([]rune, 0, len(encoded))
+	if pos != 0 {
+		for _, r := range encoded[:pos-1] {
+			output = append(output, r)
+		}
+	}
+	i, n, bias := int32(0), initialN, initialBias
+	for pos < len(encoded) {
+		oldI, w := i, int32(1)
+		for k := base; ; k += base {
+			if pos == len(encoded) {
+				return "", punyError(encoded)
+			}
+			digit, ok := decodeDigit(encoded[pos])
+			if !ok {
+				return "", punyError(encoded)
+			}
+			pos++
+			i += digit * w
+			if i < 0 {
+				return "", punyError(encoded)
+			}
+			t := k - bias
+			if t < tmin {
+				t = tmin
+			} else if t > tmax {
+				t = tmax
+			}
+			if digit < t {
+				break
+			}
+			w *= base - t
+			if w >= math.MaxInt32/base {
+				return "", punyError(encoded)
+			}
+		}
+		x := int32(len(output) + 1)
+		bias = adapt(i-oldI, x, oldI == 0)
+		n += i / x
+		i %= x
+		if n > utf8.MaxRune || len(output) >= 1024 {
+			return "", punyError(encoded)
+		}
+		output = append(output, 0)
+		copy(output[i+1:], output[i:])
+		output[i] = n
+		i++
+	}
+	return string(output), nil
+}
+
+// encode encodes a string as specified in section 6.3 and prepends prefix to
+// the result.
+//
+// The "while h < length(input)" line in the specification becomes "for
+// remaining != 0" in the Go code, because len(s) in Go is in bytes, not runes.
+func encode(prefix, s string) (string, error) {
+	output := make([]byte, len(prefix), len(prefix)+1+2*len(s))
+	copy(output, prefix)
+	delta, n, bias := int32(0), initialN, initialBias
+	b, remaining := int32(0), int32(0)
+	for _, r := range s {
+		if r < 0x80 {
+			b++
+			output = append(output, byte(r))
+		} else {
+			remaining++
+		}
+	}
+	h := b
+	if b > 0 {
+		output = append(output, '-')
+	}
+	for remaining != 0 {
+		m := int32(0x7fffffff)
+		for _, r := range s {
+			if m > r && r >= n {
+				m = r
+			}
+		}
+		delta += (m - n) * (h + 1)
+		if delta < 0 {
+			return "", punyError(s)
+		}
+		n = m
+		for _, r := range s {
+			if r < n {
+				delta++
+				if delta < 0 {
+					return "", punyError(s)
+				}
+				continue
+			}
+			if r > n {
+				continue
+			}
+			q := delta
+			for k := base; ; k += base {
+				t := k - bias
+				if t < tmin {
+					t = tmin
+				} else if t > tmax {
+					t = tmax
+				}
+				if q < t {
+					break
+				}
+				output = append(output, encodeDigit(t+(q-t)%(base-t)))
+				q = (q - t) / (base - t)
+			}
+			output = append(output, encodeDigit(q))
+			bias = adapt(delta, h+1, h == b)
+			delta = 0
+			h++
+			remaining--
+		}
+		delta++
+		n++
+	}
+	return string(output), nil
+}
+
+func decodeDigit(x byte) (digit int32, ok bool) {
+	switch {
+	case '0' <= x && x <= '9':
+		return int32(x - ('0' - 26)), true
+	case 'A' <= x && x <= 'Z':
+		return int32(x - 'A'), true
+	case 'a' <= x && x <= 'z':
+		return int32(x - 'a'), true
+	}
+	return 0, false
+}
+
+func encodeDigit(digit int32) byte {
+	switch {
+	case 0 <= digit && digit < 26:
+		return byte(digit + 'a')
+	case 26 <= digit && digit < 36:
+		return byte(digit + ('0' - 26))
+	}
+	panic("idna: internal error in punycode encoding")
+}
+
+// adapt is the bias adaptation function specified in section 6.1.
+func adapt(delta, numPoints int32, firstTime bool) int32 {
+	if firstTime {
+		delta /= damp
+	} else {
+		delta /= 2
+	}
+	delta += delta / numPoints
+	k := int32(0)
+	for delta > ((base-tmin)*tmax)/2 {
+		delta /= base - tmin
+		k += base
+	}
+	return k + (base-tmin+1)*delta/(delta+skew)
+}

vendor/golang.org/x/net/idna/trie.go

+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package idna
+
+// appendMapping appends the mapping for the respective rune. isMapped must be
+// true. A mapping is a categorization of a rune as defined in UTS #46.
+func (c info) appendMapping(b []byte, s string) []byte {
+	index := int(c >> indexShift)
+	if c&xorBit == 0 {
+		s := mappings[index:]
+		return append(b, s[1:s[0]+1]...)
+	}
+	b = append(b, s...)
+	if c&inlineXOR == inlineXOR {
+		// TODO: support and handle two-byte inline masks
+		b[len(b)-1] ^= byte(index)
+	} else {
+		for p := len(b) - int(xorData[index]); p < len(b); p++ {
+			index++
+			b[p] ^= xorData[index]
+		}
+	}
+	return b
+}
+
+// Sparse block handling code.
+
+type valueRange struct {
+	value  uint16 // header: value:stride
+	lo, hi byte   // header: lo:n
+}
+
+type sparseBlocks struct {
+	values []valueRange
+	offset []uint16
+}
+
+var idnaSparse = sparseBlocks{
+	values: idnaSparseValues[:],
+	offset: idnaSparseOffset[:],
+}
+
+// Don't use newIdnaTrie to avoid unconditional linking in of the table.
+var trie = &idnaTrie{}
+
+// lookup determines the type of block n and looks up the value for b.
+// For n < t.cutoff, the block is a simple lookup table. Otherwise, the block
+// is a list of ranges with an accompanying value. Given a matching range r,
+// the value for b is by r.value + (b - r.lo) * stride.
+func (t *sparseBlocks) lookup(n uint32, b byte) uint16 {
+	offset := t.offset[n]
+	header := t.values[offset]
+	lo := offset + 1
+	hi := lo + uint16(header.lo)
+	for lo < hi {
+		m := lo + (hi-lo)/2
+		r := t.values[m]
+		if r.lo <= b && b <= r.hi {
+			return r.value + uint16(b-r.lo)*header.value
+		}
+		if b < r.lo {
+			hi = m
+		} else {
+			lo = m + 1
+		}
+	}
+	return 0
+}

vendor/golang.org/x/net/idna/trieval.go

+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+package idna
+
+// This file contains definitions for interpreting the trie value of the idna
+// trie generated by "go run gen*.go". It is shared by both the generator
+// program and the resultant package. Sharing is achieved by the generator
+// copying gen_trieval.go to trieval.go and changing what's above this comment.
+
+// info holds information from the IDNA mapping table for a single rune. It is
+// the value returned by a trie lookup. In most cases, all information fits in
+// a 16-bit value. For mappings, this value may contain an index into a slice
+// with the mapped string. Such mappings can consist of the actual mapped value
+// or an XOR pattern to be applied to the bytes of the UTF8 encoding of the
+// input rune. This technique is used by the cases packages and reduces the
+// table size significantly.
+//
+// The per-rune values have the following format:
+//
+//   if mapped {
+//     if inlinedXOR {
+//       15..13 inline XOR marker
+//       12..11 unused
+//       10..3  inline XOR mask
+//     } else {
+//       15..3  index into xor or mapping table
+//     }
+//   } else {
+//       15..14 unused
+//       13     mayNeedNorm
+//       12..11 attributes
+//       10..8  joining type
+//        7..3  category type
+//   }
+//      2  use xor pattern
+//   1..0  mapped category
+//
+// See the definitions below for a more detailed description of the various
+// bits.
+type info uint16
+
+const (
+	catSmallMask = 0x3
+	catBigMask   = 0xF8
+	indexShift   = 3
+	xorBit       = 0x4    // interpret the index as an xor pattern
+	inlineXOR    = 0xE000 // These bits are set if the XOR pattern is inlined.
+
+	joinShift = 8
+	joinMask  = 0x07
+
+	// Attributes
+	attributesMask = 0x1800
+	viramaModifier = 0x1800
+	modifier       = 0x1000
+	rtl            = 0x0800
+
+	mayNeedNorm = 0x2000
+)
+
+// A category corresponds to a category defined in the IDNA mapping table.
+type category uint16
+
+const (
+	unknown              category = 0 // not currently defined in unicode.
+	mapped               category = 1
+	disallowedSTD3Mapped category = 2
+	deviation            category = 3
+)
+
+const (
+	valid               category = 0x08
+	validNV8            category = 0x18
+	validXV8            category = 0x28
+	disallowed          category = 0x40
+	disallowedSTD3Valid category = 0x80
+	ignored             category = 0xC0
+)
+
+// join types and additional rune information
+const (
+	joiningL = (iota + 1)
+	joiningD
+	joiningT
+	joiningR
+
+	//the following types are derived during processing
+	joinZWJ
+	joinZWNJ
+	joinVirama
+	numJoinTypes
+)
+
+func (c info) isMapped() bool {
+	return c&0x3 != 0
+}
+
+func (c info) category() category {
+	small := c & catSmallMask
+	if small != 0 {
+		return category(small)
+	}
+	return category(c & catBigMask)
+}
+
+func (c info) joinType() info {
+	if c.isMapped() {
+		return 0
+	}
+	return (c >> joinShift) & joinMask
+}
+
+func (c info) isModifier() bool {
+	return c&(modifier|catSmallMask) == modifier
+}
+
+func (c info) isViramaModifier() bool {
+	return c&(attributesMask|catSmallMask) == viramaModifier
+}

vendor/golang.org/x/text/secure/bidirule/bidirule.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package bidirule implements the Bidi Rule defined by RFC 5893.
+//
+// This package is under development. The API may change without notice and
+// without preserving backward compatibility.
+package bidirule
+
+import (
+	"errors"
+	"unicode/utf8"
+
+	"golang.org/x/text/transform"
+	"golang.org/x/text/unicode/bidi"
+)
+
+// This file contains an implementation of RFC 5893: Right-to-Left Scripts for
+// Internationalized Domain Names for Applications (IDNA)
+//
+// A label is an individual component of a domain name.  Labels are usually
+// shown separated by dots; for example, the domain name "www.example.com" is
+// composed of three labels: "www", "example", and "com".
+//
+// An RTL label is a label that contains at least one character of class R, AL,
+// or AN. An LTR label is any label that is not an RTL label.
+//
+// A "Bidi domain name" is a domain name that contains at least one RTL label.
+//
+//  The following guarantees can be made based on the above:
+//
+//  o  In a domain name consisting of only labels that satisfy the rule,
+//     the requirements of Section 3 are satisfied.  Note that even LTR
+//     labels and pure ASCII labels have to be tested.
+//
+//  o  In a domain name consisting of only LDH labels (as defined in the
+//     Definitions document [RFC5890]) and labels that satisfy the rule,
+//     the requirements of Section 3 are satisfied as long as a label
+//     that starts with an ASCII digit does not come after a
+//     right-to-left label.
+//
+//  No guarantee is given for other combinations.
+
+// ErrInvalid indicates a label is invalid according to the Bidi Rule.
+var ErrInvalid = errors.New("bidirule: failed Bidi Rule")
+
+type ruleState uint8
+
+const (
+	ruleInitial ruleState = iota
+	ruleLTR
+	ruleLTRFinal
+	ruleRTL
+	ruleRTLFinal
+	ruleInvalid
+)
+
+type ruleTransition struct {
+	next ruleState
+	mask uint16
+}
+
+var transitions = [...][2]ruleTransition{
+	// [2.1] The first character must be a character with Bidi property L, R, or
+	// AL. If it has the R or AL property, it is an RTL label; if it has the L
+	// property, it is an LTR label.
+	ruleInitial: {
+		{ruleLTRFinal, 1 << bidi.L},
+		{ruleRTLFinal, 1<<bidi.R | 1<<bidi.AL},
+	},
+	ruleRTL: {
+		// [2.3] In an RTL label, the end of the label must be a character with
+		// Bidi property R, AL, EN, or AN, followed by zero or more characters
+		// with Bidi property NSM.
+		{ruleRTLFinal, 1<<bidi.R | 1<<bidi.AL | 1<<bidi.EN | 1<<bidi.AN},
+
+		// [2.2] In an RTL label, only characters with the Bidi properties R,
+		// AL, AN, EN, ES, CS, ET, ON, BN, or NSM are allowed.
+		// We exclude the entries from [2.3]
+		{ruleRTL, 1<<bidi.ES | 1<<bidi.CS | 1<<bidi.ET | 1<<bidi.ON | 1<<bidi.BN | 1<<bidi.NSM},
+	},
+	ruleRTLFinal: {
+		// [2.3] In an RTL label, the end of the label must be a character with
+		// Bidi property R, AL, EN, or AN, followed by zero or more characters
+		// with Bidi property NSM.
+		{ruleRTLFinal, 1<<bidi.R | 1<<bidi.AL | 1<<bidi.EN | 1<<bidi.AN | 1<<bidi.NSM},
+
+		// [2.2] In an RTL label, only characters with the Bidi properties R,
+		// AL, AN, EN, ES, CS, ET, ON, BN, or NSM are allowed.
+		// We exclude the entries from [2.3] and NSM.
+		{ruleRTL, 1<<bidi.ES | 1<<bidi.CS | 1<<bidi.ET | 1<<bidi.ON | 1<<bidi.BN},
+	},
+	ruleLTR: {
+		// [2.6] In an LTR label, the end of the label must be a character with
+		// Bidi property L or EN, followed by zero or more characters with Bidi
+		// property NSM.
+		{ruleLTRFinal, 1<<bidi.L | 1<<bidi.EN},
+
+		// [2.5] In an LTR label, only characters with the Bidi properties L,
+		// EN, ES, CS, ET, ON, BN, or NSM are allowed.
+		// We exclude the entries from [2.6].
+		{ruleLTR, 1<<bidi.ES | 1<<bidi.CS | 1<<bidi.ET | 1<<bidi.ON | 1<<bidi.BN | 1<<bidi.NSM},
+	},
+	ruleLTRFinal: {
+		// [2.6] In an LTR label, the end of the label must be a character with
+		// Bidi property L or EN, followed by zero or more characters with Bidi
+		// property NSM.
+		{ruleLTRFinal, 1<<bidi.L | 1<<bidi.EN | 1<<bidi.NSM},
+
+		// [2.5] In an LTR label, only characters with the Bidi properties L,
+		// EN, ES, CS, ET, ON, BN, or NSM are allowed.
+		// We exclude the entries from [2.6].
+		{ruleLTR, 1<<bidi.ES | 1<<bidi.CS | 1<<bidi.ET | 1<<bidi.ON | 1<<bidi.BN},
+	},
+	ruleInvalid: {
+		{ruleInvalid, 0},
+		{ruleInvalid, 0},
+	},
+}
+
+// [2.4] In an RTL label, if an EN is present, no AN may be present, and
+// vice versa.
+const exclusiveRTL = uint16(1<<bidi.EN | 1<<bidi.AN)
+
+// From RFC 5893
+// An RTL label is a label that contains at least one character of type
+// R, AL, or AN.
+//
+// An LTR label is any label that is not an RTL label.
+
+// Direction reports the direction of the given label as defined by RFC 5893.
+// The Bidi Rule does not have to be applied to labels of the category
+// LeftToRight.
+func Direction(b []byte) bidi.Direction {
+	for i := 0; i < len(b); {
+		e, sz := bidi.Lookup(b[i:])
+		if sz == 0 {
+			i++
+		}
+		c := e.Class()
+		if c == bidi.R || c == bidi.AL || c == bidi.AN {
+			return bidi.RightToLeft
+		}
+		i += sz
+	}
+	return bidi.LeftToRight
+}
+
+// DirectionString reports the direction of the given label as defined by RFC
+// 5893. The Bidi Rule does not have to be applied to labels of the category
+// LeftToRight.
+func DirectionString(s string) bidi.Direction {
+	for i := 0; i < len(s); {
+		e, sz := bidi.LookupString(s[i:])
+		if sz == 0 {
+			i++
+			continue
+		}
+		c := e.Class()
+		if c == bidi.R || c == bidi.AL || c == bidi.AN {
+			return bidi.RightToLeft
+		}
+		i += sz
+	}
+	return bidi.LeftToRight
+}
+
+// Valid reports whether b conforms to the BiDi rule.
+func Valid(b []byte) bool {
+	var t Transformer
+	if n, ok := t.advance(b); !ok || n < len(b) {
+		return false
+	}
+	return t.isFinal()
+}
+
+// ValidString reports whether s conforms to the BiDi rule.
+func ValidString(s string) bool {
+	var t Transformer
+	if n, ok := t.advanceString(s); !ok || n < len(s) {
+		return false
+	}
+	return t.isFinal()
+}
+
+// New returns a Transformer that verifies that input adheres to the Bidi Rule.
+func New() *Transformer {
+	return &Transformer{}
+}
+
+// Transformer implements transform.Transform.
+type Transformer struct {
+	state  ruleState
+	hasRTL bool
+	seen   uint16
+}
+
+// A rule can only be violated for "Bidi Domain names", meaning if one of the
+// following categories has been observed.
+func (t *Transformer) isRTL() bool {
+	const isRTL = 1<<bidi.R | 1<<bidi.AL | 1<<bidi.AN
+	return t.seen&isRTL != 0
+}
+
+// Reset implements transform.Transformer.
+func (t *Transformer) Reset() { *t = Transformer{} }
+
+// Transform implements transform.Transformer. This Transformer has state and
+// needs to be reset between uses.
+func (t *Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	if len(dst) < len(src) {
+		src = src[:len(dst)]
+		atEOF = false
+		err = transform.ErrShortDst
+	}
+	n, err1 := t.Span(src, atEOF)
+	copy(dst, src[:n])
+	if err == nil || err1 != nil && err1 != transform.ErrShortSrc {
+		err = err1
+	}
+	return n, n, err
+}
+
+// Span returns the first n bytes of src that conform to the Bidi rule.
+func (t *Transformer) Span(src []byte, atEOF bool) (n int, err error) {
+	if t.state == ruleInvalid && t.isRTL() {
+		return 0, ErrInvalid
+	}
+	n, ok := t.advance(src)
+	switch {
+	case !ok:
+		err = ErrInvalid
+	case n < len(src):
+		if !atEOF {
+			err = transform.ErrShortSrc
+			break
+		}
+		err = ErrInvalid
+	case !t.isFinal():
+		err = ErrInvalid
+	}
+	return n, err
+}
+
+// Precomputing the ASCII values decreases running time for the ASCII fast path
+// by about 30%.
+var asciiTable [128]bidi.Properties
+
+func init() {
+	for i := range asciiTable {
+		p, _ := bidi.LookupRune(rune(i))
+		asciiTable[i] = p
+	}
+}
+
+func (t *Transformer) advance(s []byte) (n int, ok bool) {
+	var e bidi.Properties
+	var sz int
+	for n < len(s) {
+		if s[n] < utf8.RuneSelf {
+			e, sz = asciiTable[s[n]], 1
+		} else {
+			e, sz = bidi.Lookup(s[n:])
+			if sz <= 1 {
+				if sz == 1 {
+					// We always consider invalid UTF-8 to be invalid, even if
+					// the string has not yet been determined to be RTL.
+					// TODO: is this correct?
+					return n, false
+				}
+				return n, true // incomplete UTF-8 encoding
+			}
+		}
+		// TODO: using CompactClass would result in noticeable speedup.
+		// See unicode/bidi/prop.go:Properties.CompactClass.
+		c := uint16(1 << e.Class())
+		t.seen |= c
+		if t.seen&exclusiveRTL == exclusiveRTL {
+			t.state = ruleInvalid
+			return n, false
+		}
+		switch tr := transitions[t.state]; {
+		case tr[0].mask&c != 0:
+			t.state = tr[0].next
+		case tr[1].mask&c != 0:
+			t.state = tr[1].next
+		default:
+			t.state = ruleInvalid
+			if t.isRTL() {
+				return n, false
+			}
+		}
+		n += sz
+	}
+	return n, true
+}
+
+func (t *Transformer) advanceString(s string) (n int, ok bool) {
+	var e bidi.Properties
+	var sz int
+	for n < len(s) {
+		if s[n] < utf8.RuneSelf {
+			e, sz = asciiTable[s[n]], 1
+		} else {
+			e, sz = bidi.LookupString(s[n:])
+			if sz <= 1 {
+				if sz == 1 {
+					return n, false // invalid UTF-8
+				}
+				return n, true // incomplete UTF-8 encoding
+			}
+		}
+		// TODO: using CompactClass results in noticeable speedup.
+		// See unicode/bidi/prop.go:Properties.CompactClass.
+		c := uint16(1 << e.Class())
+		t.seen |= c
+		if t.seen&exclusiveRTL == exclusiveRTL {
+			t.state = ruleInvalid
+			return n, false
+		}
+		switch tr := transitions[t.state]; {
+		case tr[0].mask&c != 0:
+			t.state = tr[0].next
+		case tr[1].mask&c != 0:
+			t.state = tr[1].next
+		default:
+			t.state = ruleInvalid
+			if t.isRTL() {
+				return n, false
+			}
+		}
+		n += sz
+	}
+	return n, true
+}

vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.10
+
+package bidirule
+
+func (t *Transformer) isFinal() bool {
+	return t.state == ruleLTRFinal || t.state == ruleRTLFinal || t.state == ruleInitial
+}

vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.10
+
+package bidirule
+
+func (t *Transformer) isFinal() bool {
+	if !t.isRTL() {
+		return true
+	}
+	return t.state == ruleLTRFinal || t.state == ruleRTLFinal || t.state == ruleInitial
+}

vendor/golang.org/x/text/unicode/bidi/bidi.go

+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate go run gen.go gen_trieval.go gen_ranges.go
+
+// Package bidi contains functionality for bidirectional text support.
+//
+// See http://www.unicode.org/reports/tr9.
+//
+// NOTE: UNDER CONSTRUCTION. This API may change in backwards incompatible ways
+// 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:
+// - Transformer for reordering?
+// - Transformer (validator, really) for Bidi Rule.
+
+// 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
+// embedding hierarchy, though.
+
+// A Direction indicates the overall flow of text.
+type Direction int
+
+const (
+	// LeftToRight indicates the text contains no right-to-left characters and
+	// that either there are some left-to-right characters or the option
+	// DefaultDirection(LeftToRight) was passed.
+	LeftToRight Direction = iota
+
+	// RightToLeft indicates the text contains no left-to-right characters and
+	// that either there are some right-to-left characters or the option
+	// DefaultDirection(RightToLeft) was passed.
+	RightToLeft
+
+	// Mixed indicates text contains both left-to-right and right-to-left
+	// characters.
+	Mixed
+
+	// Neutral means that text contains no left-to-right and right-to-left
+	// characters and that no default direction has been set.
+	Neutral
+)
+
+type options struct{}
+
+// An Option is an option for Bidi processing.
+type Option func(*options)
+
+// ICU allows the user to define embedding levels. This may be used, for example,
+// to use hierarchical structure of markup languages to define embeddings.
+// The following option may be a way to expose this functionality in this API.
+// // LevelFunc sets a function that associates nesting levels with the given text.
+// // The levels function will be called with monotonically increasing values for p.
+// func LevelFunc(levels func(p int) int) Option {
+// 	panic("unimplemented")
+// }
+
+// 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")
+}
+
+// A Paragraph holds a single Paragraph for Bidi processing.
+type Paragraph struct {
+	// buffers
+}
+
+// SetBytes configures p for the given paragraph text. It replaces text
+// previously set by SetBytes or SetString. If b 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
+// given.
+func (p *Paragraph) SetBytes(b []byte, opts ...Option) (n int, err error) {
+	panic("unimplemented")
+}
+
+// SetString configures p for the given paragraph text. It replaces text
+// previously set by SetBytes or SetString. If b 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
+// given.
+func (p *Paragraph) SetString(s string, opts ...Option) (n int, err error) {
+	panic("unimplemented")
+}
+
+// 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")
+}
+
+// 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")
+}
+
+// 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")
+}
+
+// Order computes the visual ordering of all the runs in a Paragraph.
+func (p *Paragraph) Order() (Ordering, error) {
+	panic("unimplemented")
+}
+
+// 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")
+}
+
+// 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{}
+
+// Direction reports the directionality of the runs.
+//
+// The direction may be LeftToRight, RightToLeft, Mixed, or Neutral.
+func (o *Ordering) Direction() Direction {
+	panic("unimplemented")
+}
+
+// NumRuns returns the number of runs.
+func (o *Ordering) NumRuns() int {
+	panic("unimplemented")
+}
+
+// Run returns the ith run within the ordering.
+func (o *Ordering) Run(i int) Run {
+	panic("unimplemented")
+}
+
+// TODO: perhaps with options.
+// // Reorder creates a reader that reads the runes in visual order per character.
+// // Modifiers remain after the runes they modify.
+// func (l *Runs) Reorder() io.Reader {
+// 	panic("unimplemented")
+// }
+
+// A Run is a continuous sequence of characters of a single direction.
+type Run struct {
+}
+
+// String returns the text of the run in its original order.
+func (r *Run) String() string {
+	panic("unimplemented")
+}
+
+// Bytes returns the text of the run in its original order.
+func (r *Run) Bytes() []byte {
+	panic("unimplemented")
+}
+
+// TODO: methods for
+// - Display order
+// - headers and footers
+// - bracket replacement.
+
+// Direction reports the direction of the run.
+func (r *Run) Direction() Direction {
+	panic("unimplemented")
+}
+
+// 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")
+}
+
+// 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")
+}
+
+// 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")
+}

vendor/golang.org/x/text/unicode/bidi/prop.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bidi
+
+import "unicode/utf8"
+
+// Properties provides access to BiDi properties of runes.
+type Properties struct {
+	entry uint8
+	last  uint8
+}
+
+var trie = newBidiTrie(0)
+
+// TODO: using this for bidirule reduces the running time by about 5%. Consider
+// if this is worth exposing or if we can find a way to speed up the Class
+// method.
+//
+// // CompactClass is like Class, but maps all of the BiDi control classes
+// // (LRO, RLO, LRE, RLE, PDF, LRI, RLI, FSI, PDI) to the class Control.
+// func (p Properties) CompactClass() Class {
+// 	return Class(p.entry & 0x0F)
+// }
+
+// Class returns the Bidi class for p.
+func (p Properties) Class() Class {
+	c := Class(p.entry & 0x0F)
+	if c == Control {
+		c = controlByteToClass[p.last&0xF]
+	}
+	return c
+}
+
+// IsBracket reports whether the rune is a bracket.
+func (p Properties) IsBracket() bool { return p.entry&0xF0 != 0 }
+
+// IsOpeningBracket reports whether the rune is an opening bracket.
+// IsBracket must return true.
+func (p Properties) IsOpeningBracket() bool { return p.entry&openMask != 0 }
+
+// TODO: find a better API and expose.
+func (p Properties) reverseBracket(r rune) rune {
+	return xorMasks[p.entry>>xorMaskShift] ^ r
+}
+
+var controlByteToClass = [16]Class{
+	0xD: LRO, // U+202D LeftToRightOverride,
+	0xE: RLO, // U+202E RightToLeftOverride,
+	0xA: LRE, // U+202A LeftToRightEmbedding,
+	0xB: RLE, // U+202B RightToLeftEmbedding,
+	0xC: PDF, // U+202C PopDirectionalFormat,
+	0x6: LRI, // U+2066 LeftToRightIsolate,
+	0x7: RLI, // U+2067 RightToLeftIsolate,
+	0x8: FSI, // U+2068 FirstStrongIsolate,
+	0x9: PDI, // U+2069 PopDirectionalIsolate,
+}
+
+// LookupRune returns properties for r.
+func LookupRune(r rune) (p Properties, size int) {
+	var buf [4]byte
+	n := utf8.EncodeRune(buf[:], r)
+	return Lookup(buf[:n])
+}
+
+// TODO: these lookup methods are based on the generated trie code. The returned
+// sizes have slightly different semantics from the generated code, in that it
+// always returns size==1 for an illegal UTF-8 byte (instead of the length
+// of the maximum invalid subsequence). Most Transformers, like unicode/norm,
+// leave invalid UTF-8 untouched, in which case it has performance benefits to
+// do so (without changing the semantics). Bidi requires the semantics used here
+// for the bidirule implementation to be compatible with the Go semantics.
+//  They ultimately should perhaps be adopted by all trie implementations, for
+// convenience sake.
+// This unrolled code also boosts performance of the secure/bidirule package by
+// about 30%.
+// So, to remove this code:
+//   - add option to trie generator to define return type.
+//   - always return 1 byte size for ill-formed UTF-8 runes.
+
+// Lookup returns properties for the first rune in s and the width in bytes of
+// its encoding. The size will be 0 if s does not hold enough bytes to complete
+// the encoding.
+func Lookup(s []byte) (p Properties, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < 0x80: // is ASCII
+		return Properties{entry: bidiValues[c0]}, 1
+	case c0 < 0xC2:
+		return Properties{}, 1
+	case c0 < 0xE0: // 2-byte UTF-8
+		if len(s) < 2 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c1)}, 2
+	case c0 < 0xF0: // 3-byte UTF-8
+		if len(s) < 3 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = bidiIndex[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c2), last: c2}, 3
+	case c0 < 0xF8: // 4-byte UTF-8
+		if len(s) < 4 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = bidiIndex[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return Properties{}, 1
+		}
+		o = uint32(i)<<6 + uint32(c2)
+		i = bidiIndex[o]
+		c3 := s[3]
+		if c3 < 0x80 || 0xC0 <= c3 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c3)}, 4
+	}
+	// Illegal rune
+	return Properties{}, 1
+}
+
+// LookupString returns properties for the first rune in s and the width in
+// bytes of its encoding. The size will be 0 if s does not hold enough bytes to
+// complete the encoding.
+func LookupString(s string) (p Properties, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < 0x80: // is ASCII
+		return Properties{entry: bidiValues[c0]}, 1
+	case c0 < 0xC2:
+		return Properties{}, 1
+	case c0 < 0xE0: // 2-byte UTF-8
+		if len(s) < 2 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c1)}, 2
+	case c0 < 0xF0: // 3-byte UTF-8
+		if len(s) < 3 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = bidiIndex[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c2), last: c2}, 3
+	case c0 < 0xF8: // 4-byte UTF-8
+		if len(s) < 4 {
+			return Properties{}, 0
+		}
+		i := bidiIndex[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return Properties{}, 1
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = bidiIndex[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return Properties{}, 1
+		}
+		o = uint32(i)<<6 + uint32(c2)
+		i = bidiIndex[o]
+		c3 := s[3]
+		if c3 < 0x80 || 0xC0 <= c3 {
+			return Properties{}, 1
+		}
+		return Properties{entry: trie.lookupValue(uint32(i), c3)}, 4
+	}
+	// Illegal rune
+	return Properties{}, 1
+}

vendor/golang.org/x/text/unicode/bidi/trieval.go

+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+package bidi
+
+// Class is the Unicode BiDi class. Each rune has a single class.
+type Class uint
+
+const (
+	L       Class = iota // LeftToRight
+	R                    // RightToLeft
+	EN                   // EuropeanNumber
+	ES                   // EuropeanSeparator
+	ET                   // EuropeanTerminator
+	AN                   // ArabicNumber
+	CS                   // CommonSeparator
+	B                    // ParagraphSeparator
+	S                    // SegmentSeparator
+	WS                   // WhiteSpace
+	ON                   // OtherNeutral
+	BN                   // BoundaryNeutral
+	NSM                  // NonspacingMark
+	AL                   // ArabicLetter
+	Control              // Control LRO - PDI
+
+	numClass
+
+	LRO // LeftToRightOverride
+	RLO // RightToLeftOverride
+	LRE // LeftToRightEmbedding
+	RLE // RightToLeftEmbedding
+	PDF // PopDirectionalFormat
+	LRI // LeftToRightIsolate
+	RLI // RightToLeftIsolate
+	FSI // FirstStrongIsolate
+	PDI // PopDirectionalIsolate
+
+	unknownClass = ^Class(0)
+)
+
+var controlToClass = map[rune]Class{
+	0x202D: LRO, // LeftToRightOverride,
+	0x202E: RLO, // RightToLeftOverride,
+	0x202A: LRE, // LeftToRightEmbedding,
+	0x202B: RLE, // RightToLeftEmbedding,
+	0x202C: PDF, // PopDirectionalFormat,
+	0x2066: LRI, // LeftToRightIsolate,
+	0x2067: RLI, // RightToLeftIsolate,
+	0x2068: FSI, // FirstStrongIsolate,
+	0x2069: PDI, // PopDirectionalIsolate,
+}
+
+// A trie entry has the following bits:
+// 7..5  XOR mask for brackets
+// 4     1: Bracket open, 0: Bracket close
+// 3..0  Class type
+
+const (
+	openMask     = 0x10
+	xorMaskShift = 5
+)