fix: add involves edge from task to agent:nomos at creation

Plus sync vendor directory for Docker build compatibility.

vendor/github.com/yosida95/uritemplate/v3/LICENSE

@@ -0,0 +1,25 @@
+Copyright (C) 2016, Kohei YOSHIDA <https://yosida95.com/>. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the copyright holder nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/yosida95/uritemplate/v3/README.rst

@@ -0,0 +1,46 @@
+uritemplate
+===========
+
+`uritemplate`_ is a Go implementation of `URI Template`_ [RFC6570] with
+full functionality of URI Template Level 4.
+
+uritemplate can also generate a regexp that matches expansion of the
+URI Template from a URI Template.
+
+Getting Started
+---------------
+
+Installation
+~~~~~~~~~~~~
+
+.. code-block:: sh
+
+   $ go get -u github.com/yosida95/uritemplate/v3
+
+Documentation
+~~~~~~~~~~~~~
+
+The documentation is available on GoDoc_.
+
+Examples
+--------
+
+See `examples on GoDoc`_.
+
+License
+-------
+
+`uritemplate`_ is distributed under the BSD 3-Clause license.
+PLEASE READ ./LICENSE carefully and follow its clauses to use this software.
+
+Author
+------
+
+yosida95_
+
+
+.. _`URI Template`: https://tools.ietf.org/html/rfc6570
+.. _Godoc: https://godoc.org/github.com/yosida95/uritemplate
+.. _`examples on GoDoc`: https://godoc.org/github.com/yosida95/uritemplate#pkg-examples
+.. _yosida95: https://yosida95.com/
+.. _uritemplate: https://github.com/yosida95/uritemplate

vendor/github.com/yosida95/uritemplate/v3/compile.go

@@ -0,0 +1,224 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"fmt"
+	"unicode/utf8"
+)
+
+type compiler struct {
+	prog *prog
+}
+
+func (c *compiler) init() {
+	c.prog = &prog{}
+}
+
+func (c *compiler) op(opcode progOpcode) uint32 {
+	i := len(c.prog.op)
+	c.prog.op = append(c.prog.op, progOp{code: opcode})
+	return uint32(i)
+}
+
+func (c *compiler) opWithRune(opcode progOpcode, r rune) uint32 {
+	addr := c.op(opcode)
+	(&c.prog.op[addr]).r = r
+	return addr
+}
+
+func (c *compiler) opWithRuneClass(opcode progOpcode, rc runeClass) uint32 {
+	addr := c.op(opcode)
+	(&c.prog.op[addr]).rc = rc
+	return addr
+}
+
+func (c *compiler) opWithAddr(opcode progOpcode, absaddr uint32) uint32 {
+	addr := c.op(opcode)
+	(&c.prog.op[addr]).i = absaddr
+	return addr
+}
+
+func (c *compiler) opWithAddrDelta(opcode progOpcode, delta uint32) uint32 {
+	return c.opWithAddr(opcode, uint32(len(c.prog.op))+delta)
+}
+
+func (c *compiler) opWithName(opcode progOpcode, name string) uint32 {
+	addr := c.op(opcode)
+	(&c.prog.op[addr]).name = name
+	return addr
+}
+
+func (c *compiler) compileString(str string) {
+	for i := 0; i < len(str); {
+		// NOTE(yosida95): It is confirmed at parse time that literals
+		// consist of only valid-UTF8 runes.
+		r, size := utf8.DecodeRuneInString(str[i:])
+		c.opWithRune(opRune, r)
+		i += size
+	}
+}
+
+func (c *compiler) compileRuneClass(rc runeClass, maxlen int) {
+	for i := 0; i < maxlen; i++ {
+		if i > 0 {
+			c.opWithAddrDelta(opSplit, 7)
+		}
+		c.opWithAddrDelta(opSplit, 3)                 // raw rune or pct-encoded
+		c.opWithRuneClass(opRuneClass, rc)            // raw rune
+		c.opWithAddrDelta(opJmp, 4)                   //
+		c.opWithRune(opRune, '%')                     // pct-encoded
+		c.opWithRuneClass(opRuneClass, runeClassPctE) //
+		c.opWithRuneClass(opRuneClass, runeClassPctE) //
+	}
+}
+
+func (c *compiler) compileRuneClassInfinite(rc runeClass) {
+	start := c.opWithAddrDelta(opSplit, 3)        // raw rune or pct-encoded
+	c.opWithRuneClass(opRuneClass, rc)            // raw rune
+	c.opWithAddrDelta(opJmp, 4)                   //
+	c.opWithRune(opRune, '%')                     // pct-encoded
+	c.opWithRuneClass(opRuneClass, runeClassPctE) //
+	c.opWithRuneClass(opRuneClass, runeClassPctE) //
+	c.opWithAddrDelta(opSplit, 2)                 // loop
+	c.opWithAddr(opJmp, start)                    //
+}
+
+func (c *compiler) compileVarspecValue(spec varspec, expr *expression) {
+	var specname string
+	if spec.maxlen > 0 {
+		specname = fmt.Sprintf("%s:%d", spec.name, spec.maxlen)
+	} else {
+		specname = spec.name
+	}
+
+	c.prog.numCap++
+
+	c.opWithName(opCapStart, specname)
+
+	split := c.op(opSplit)
+	if spec.maxlen > 0 {
+		c.compileRuneClass(expr.allow, spec.maxlen)
+	} else {
+		c.compileRuneClassInfinite(expr.allow)
+	}
+
+	capEnd := c.opWithName(opCapEnd, specname)
+	c.prog.op[split].i = capEnd
+}
+
+func (c *compiler) compileVarspec(spec varspec, expr *expression) {
+	switch {
+	case expr.named && spec.explode:
+		split1 := c.op(opSplit)
+		noop := c.op(opNoop)
+		c.compileString(spec.name)
+
+		split2 := c.op(opSplit)
+		c.opWithRune(opRune, '=')
+		c.compileVarspecValue(spec, expr)
+
+		split3 := c.op(opSplit)
+		c.compileString(expr.sep)
+		c.opWithAddr(opJmp, noop)
+
+		c.prog.op[split2].i = uint32(len(c.prog.op))
+		c.compileString(expr.ifemp)
+		c.opWithAddr(opJmp, split3)
+
+		c.prog.op[split1].i = uint32(len(c.prog.op))
+		c.prog.op[split3].i = uint32(len(c.prog.op))
+
+	case expr.named && !spec.explode:
+		c.compileString(spec.name)
+
+		split2 := c.op(opSplit)
+		c.opWithRune(opRune, '=')
+
+		split3 := c.op(opSplit)
+
+		split4 := c.op(opSplit)
+		c.compileVarspecValue(spec, expr)
+
+		split5 := c.op(opSplit)
+		c.prog.op[split4].i = split5
+		c.compileString(",")
+		c.opWithAddr(opJmp, split4)
+
+		c.prog.op[split3].i = uint32(len(c.prog.op))
+		c.compileString(",")
+		jmp1 := c.op(opJmp)
+
+		c.prog.op[split2].i = uint32(len(c.prog.op))
+		c.compileString(expr.ifemp)
+
+		c.prog.op[split5].i = uint32(len(c.prog.op))
+		c.prog.op[jmp1].i = uint32(len(c.prog.op))
+
+	case !expr.named:
+		start := uint32(len(c.prog.op))
+		c.compileVarspecValue(spec, expr)
+
+		split1 := c.op(opSplit)
+		jmp := c.op(opJmp)
+
+		c.prog.op[split1].i = uint32(len(c.prog.op))
+		if spec.explode {
+			c.compileString(expr.sep)
+		} else {
+			c.opWithRune(opRune, ',')
+		}
+		c.opWithAddr(opJmp, start)
+
+		c.prog.op[jmp].i = uint32(len(c.prog.op))
+	}
+}
+
+func (c *compiler) compileExpression(expr *expression) {
+	if len(expr.vars) < 1 {
+		return
+	}
+
+	split1 := c.op(opSplit)
+	c.compileString(expr.first)
+
+	for i, size := 0, len(expr.vars); i < size; i++ {
+		spec := expr.vars[i]
+
+		split2 := c.op(opSplit)
+		if i > 0 {
+			split3 := c.op(opSplit)
+			c.compileString(expr.sep)
+			c.prog.op[split3].i = uint32(len(c.prog.op))
+		}
+		c.compileVarspec(spec, expr)
+		c.prog.op[split2].i = uint32(len(c.prog.op))
+	}
+
+	c.prog.op[split1].i = uint32(len(c.prog.op))
+}
+
+func (c *compiler) compileLiterals(lt literals) {
+	c.compileString(string(lt))
+}
+
+func (c *compiler) compile(tmpl *Template) {
+	c.op(opLineBegin)
+	for i := range tmpl.exprs {
+		expr := tmpl.exprs[i]
+		switch expr := expr.(type) {
+		default:
+			panic("unhandled expression")
+		case *expression:
+			c.compileExpression(expr)
+		case literals:
+			c.compileLiterals(expr)
+		}
+	}
+	c.op(opLineEnd)
+	c.op(opEnd)
+}

vendor/github.com/yosida95/uritemplate/v3/equals.go

@@ -0,0 +1,53 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+type CompareFlags uint8
+
+const (
+	CompareVarname CompareFlags = 1 << iota
+)
+
+// Equals reports whether or not two URI Templates t1 and t2 are equivalent.
+func Equals(t1 *Template, t2 *Template, flags CompareFlags) bool {
+	if len(t1.exprs) != len(t2.exprs) {
+		return false
+	}
+	for i := 0; i < len(t1.exprs); i++ {
+		switch t1 := t1.exprs[i].(type) {
+		case literals:
+			t2, ok := t2.exprs[i].(literals)
+			if !ok {
+				return false
+			}
+			if t1 != t2 {
+				return false
+			}
+		case *expression:
+			t2, ok := t2.exprs[i].(*expression)
+			if !ok {
+				return false
+			}
+			if t1.op != t2.op || len(t1.vars) != len(t2.vars) {
+				return false
+			}
+			for n := 0; n < len(t1.vars); n++ {
+				v1 := t1.vars[n]
+				v2 := t2.vars[n]
+				if flags&CompareVarname == CompareVarname && v1.name != v2.name {
+					return false
+				}
+				if v1.maxlen != v2.maxlen || v1.explode != v2.explode {
+					return false
+				}
+			}
+		default:
+			panic("unhandled case")
+		}
+	}
+	return true
+}

vendor/github.com/yosida95/uritemplate/v3/error.go

@@ -0,0 +1,16 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"fmt"
+)
+
+func errorf(pos int, format string, a ...interface{}) error {
+	msg := fmt.Sprintf(format, a...)
+	return fmt.Errorf("uritemplate:%d:%s", pos, msg)
+}

vendor/github.com/yosida95/uritemplate/v3/escape.go

@@ -0,0 +1,190 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+var (
+	hex = []byte("0123456789ABCDEF")
+	// reserved   = gen-delims / sub-delims
+	// gen-delims =  ":" / "/" / "?" / "#" / "[" / "]" / "@"
+	// sub-delims =  "!" / "$" / "&" / "’" / "(" / ")"
+	//            /  "*" / "+" / "," / ";" / "="
+	rangeReserved = &unicode.RangeTable{
+		R16: []unicode.Range16{
+			{Lo: 0x21, Hi: 0x21, Stride: 1}, // '!'
+			{Lo: 0x23, Hi: 0x24, Stride: 1}, // '#' - '$'
+			{Lo: 0x26, Hi: 0x2C, Stride: 1}, // '&' - ','
+			{Lo: 0x2F, Hi: 0x2F, Stride: 1}, // '/'
+			{Lo: 0x3A, Hi: 0x3B, Stride: 1}, // ':' - ';'
+			{Lo: 0x3D, Hi: 0x3D, Stride: 1}, // '='
+			{Lo: 0x3F, Hi: 0x40, Stride: 1}, // '?' - '@'
+			{Lo: 0x5B, Hi: 0x5B, Stride: 1}, // '['
+			{Lo: 0x5D, Hi: 0x5D, Stride: 1}, // ']'
+		},
+		LatinOffset: 9,
+	}
+	reReserved = `\x21\x23\x24\x26-\x2c\x2f\x3a\x3b\x3d\x3f\x40\x5b\x5d`
+	// ALPHA      = %x41-5A / %x61-7A
+	// DIGIT      = %x30-39
+	// unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
+	rangeUnreserved = &unicode.RangeTable{
+		R16: []unicode.Range16{
+			{Lo: 0x2D, Hi: 0x2E, Stride: 1}, // '-' - '.'
+			{Lo: 0x30, Hi: 0x39, Stride: 1}, // '0' - '9'
+			{Lo: 0x41, Hi: 0x5A, Stride: 1}, // 'A' - 'Z'
+			{Lo: 0x5F, Hi: 0x5F, Stride: 1}, // '_'
+			{Lo: 0x61, Hi: 0x7A, Stride: 1}, // 'a' - 'z'
+			{Lo: 0x7E, Hi: 0x7E, Stride: 1}, // '~'
+		},
+	}
+	reUnreserved = `\x2d\x2e\x30-\x39\x41-\x5a\x5f\x61-\x7a\x7e`
+)
+
+type runeClass uint8
+
+const (
+	runeClassU runeClass = 1 << iota
+	runeClassR
+	runeClassPctE
+	runeClassLast
+
+	runeClassUR = runeClassU | runeClassR
+)
+
+var runeClassNames = []string{
+	"U",
+	"R",
+	"pct-encoded",
+}
+
+func (rc runeClass) String() string {
+	ret := make([]string, 0, len(runeClassNames))
+	for i, j := 0, runeClass(1); j < runeClassLast; j <<= 1 {
+		if rc&j == j {
+			ret = append(ret, runeClassNames[i])
+		}
+		i++
+	}
+	return strings.Join(ret, "+")
+}
+
+func pctEncode(w *strings.Builder, r rune) {
+	if s := r >> 24 & 0xff; s > 0 {
+		w.Write([]byte{'%', hex[s/16], hex[s%16]})
+	}
+	if s := r >> 16 & 0xff; s > 0 {
+		w.Write([]byte{'%', hex[s/16], hex[s%16]})
+	}
+	if s := r >> 8 & 0xff; s > 0 {
+		w.Write([]byte{'%', hex[s/16], hex[s%16]})
+	}
+	if s := r & 0xff; s > 0 {
+		w.Write([]byte{'%', hex[s/16], hex[s%16]})
+	}
+}
+
+func unhex(c byte) byte {
+	switch {
+	case '0' <= c && c <= '9':
+		return c - '0'
+	case 'a' <= c && c <= 'f':
+		return c - 'a' + 10
+	case 'A' <= c && c <= 'F':
+		return c - 'A' + 10
+	}
+	return 0
+}
+
+func ishex(c byte) bool {
+	switch {
+	case '0' <= c && c <= '9':
+		return true
+	case 'a' <= c && c <= 'f':
+		return true
+	case 'A' <= c && c <= 'F':
+		return true
+	default:
+		return false
+	}
+}
+
+func pctDecode(s string) string {
+	size := len(s)
+	for i := 0; i < len(s); {
+		switch s[i] {
+		case '%':
+			size -= 2
+			i += 3
+		default:
+			i++
+		}
+	}
+	if size == len(s) {
+		return s
+	}
+
+	buf := make([]byte, size)
+	j := 0
+	for i := 0; i < len(s); {
+		switch c := s[i]; c {
+		case '%':
+			buf[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
+			i += 3
+			j++
+		default:
+			buf[j] = c
+			i++
+			j++
+		}
+	}
+	return string(buf)
+}
+
+type escapeFunc func(*strings.Builder, string) error
+
+func escapeLiteral(w *strings.Builder, v string) error {
+	w.WriteString(v)
+	return nil
+}
+
+func escapeExceptU(w *strings.Builder, v string) error {
+	for i := 0; i < len(v); {
+		r, size := utf8.DecodeRuneInString(v[i:])
+		if r == utf8.RuneError {
+			return errorf(i, "invalid encoding")
+		}
+		if unicode.Is(rangeUnreserved, r) {
+			w.WriteRune(r)
+		} else {
+			pctEncode(w, r)
+		}
+		i += size
+	}
+	return nil
+}
+
+func escapeExceptUR(w *strings.Builder, v string) error {
+	for i := 0; i < len(v); {
+		r, size := utf8.DecodeRuneInString(v[i:])
+		if r == utf8.RuneError {
+			return errorf(i, "invalid encoding")
+		}
+		// TODO(yosida95): is pct-encoded triplets allowed here?
+		if unicode.In(r, rangeUnreserved, rangeReserved) {
+			w.WriteRune(r)
+		} else {
+			pctEncode(w, r)
+		}
+		i += size
+	}
+	return nil
+}

vendor/github.com/yosida95/uritemplate/v3/expression.go

@@ -0,0 +1,173 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type template interface {
+	expand(*strings.Builder, Values) error
+	regexp(*strings.Builder)
+}
+
+type literals string
+
+func (l literals) expand(b *strings.Builder, _ Values) error {
+	b.WriteString(string(l))
+	return nil
+}
+
+func (l literals) regexp(b *strings.Builder) {
+	b.WriteString("(?:")
+	b.WriteString(regexp.QuoteMeta(string(l)))
+	b.WriteByte(')')
+}
+
+type varspec struct {
+	name    string
+	maxlen  int
+	explode bool
+}
+
+type expression struct {
+	vars   []varspec
+	op     parseOp
+	first  string
+	sep    string
+	named  bool
+	ifemp  string
+	escape escapeFunc
+	allow  runeClass
+}
+
+func (e *expression) init() {
+	switch e.op {
+	case parseOpSimple:
+		e.sep = ","
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	case parseOpPlus:
+		e.sep = ","
+		e.escape = escapeExceptUR
+		e.allow = runeClassUR
+	case parseOpCrosshatch:
+		e.first = "#"
+		e.sep = ","
+		e.escape = escapeExceptUR
+		e.allow = runeClassUR
+	case parseOpDot:
+		e.first = "."
+		e.sep = "."
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	case parseOpSlash:
+		e.first = "/"
+		e.sep = "/"
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	case parseOpSemicolon:
+		e.first = ";"
+		e.sep = ";"
+		e.named = true
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	case parseOpQuestion:
+		e.first = "?"
+		e.sep = "&"
+		e.named = true
+		e.ifemp = "="
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	case parseOpAmpersand:
+		e.first = "&"
+		e.sep = "&"
+		e.named = true
+		e.ifemp = "="
+		e.escape = escapeExceptU
+		e.allow = runeClassU
+	}
+}
+
+func (e *expression) expand(w *strings.Builder, values Values) error {
+	first := true
+	for _, varspec := range e.vars {
+		value := values.Get(varspec.name)
+		if !value.Valid() {
+			continue
+		}
+
+		if first {
+			w.WriteString(e.first)
+			first = false
+		} else {
+			w.WriteString(e.sep)
+		}
+
+		if err := value.expand(w, varspec, e); err != nil {
+			return err
+		}
+
+	}
+	return nil
+}
+
+func (e *expression) regexp(b *strings.Builder) {
+	if e.first != "" {
+		b.WriteString("(?:") // $1
+		b.WriteString(regexp.QuoteMeta(e.first))
+	}
+	b.WriteByte('(') // $2
+	runeClassToRegexp(b, e.allow, e.named || e.vars[0].explode)
+	if len(e.vars) > 1 || e.vars[0].explode {
+		max := len(e.vars) - 1
+		for i := 0; i < len(e.vars); i++ {
+			if e.vars[i].explode {
+				max = -1
+				break
+			}
+		}
+
+		b.WriteString("(?:") // $3
+		b.WriteString(regexp.QuoteMeta(e.sep))
+		runeClassToRegexp(b, e.allow, e.named || max < 0)
+		b.WriteByte(')') // $3
+		if max > 0 {
+			b.WriteString("{0,")
+			b.WriteString(strconv.Itoa(max))
+			b.WriteByte('}')
+		} else {
+			b.WriteByte('*')
+		}
+	}
+	b.WriteByte(')') // $2
+	if e.first != "" {
+		b.WriteByte(')') // $1
+	}
+	b.WriteByte('?')
+}
+
+func runeClassToRegexp(b *strings.Builder, class runeClass, named bool) {
+	b.WriteString("(?:(?:[")
+	if class&runeClassR == 0 {
+		b.WriteString(`\x2c`)
+		if named {
+			b.WriteString(`\x3d`)
+		}
+	}
+	if class&runeClassU == runeClassU {
+		b.WriteString(reUnreserved)
+	}
+	if class&runeClassR == runeClassR {
+		b.WriteString(reReserved)
+	}
+	b.WriteString("]")
+	b.WriteString("|%[[:xdigit:]][[:xdigit:]]")
+	b.WriteString(")*)")
+}

vendor/github.com/yosida95/uritemplate/v3/machine.go

@@ -0,0 +1,23 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+// threadList implements https://research.swtch.com/sparse.
+type threadList struct {
+	dense  []threadEntry
+	sparse []uint32
+}
+
+type threadEntry struct {
+	pc uint32
+	t  *thread
+}
+
+type thread struct {
+	op  *progOp
+	cap map[string][]int
+}

vendor/github.com/yosida95/uritemplate/v3/match.go

@@ -0,0 +1,213 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"bytes"
+	"unicode"
+	"unicode/utf8"
+)
+
+type matcher struct {
+	prog *prog
+
+	list1   threadList
+	list2   threadList
+	matched bool
+	cap     map[string][]int
+
+	input string
+}
+
+func (m *matcher) at(pos int) (rune, int, bool) {
+	if l := len(m.input); pos < l {
+		c := m.input[pos]
+		if c < utf8.RuneSelf {
+			return rune(c), 1, pos+1 < l
+		}
+		r, size := utf8.DecodeRuneInString(m.input[pos:])
+		return r, size, pos+size < l
+	}
+	return -1, 0, false
+}
+
+func (m *matcher) add(list *threadList, pc uint32, pos int, next bool, cap map[string][]int) {
+	if i := list.sparse[pc]; i < uint32(len(list.dense)) && list.dense[i].pc == pc {
+		return
+	}
+
+	n := len(list.dense)
+	list.dense = list.dense[:n+1]
+	list.sparse[pc] = uint32(n)
+
+	e := &list.dense[n]
+	e.pc = pc
+	e.t = nil
+
+	op := &m.prog.op[pc]
+	switch op.code {
+	default:
+		panic("unhandled opcode")
+	case opRune, opRuneClass, opEnd:
+		e.t = &thread{
+			op:  &m.prog.op[pc],
+			cap: make(map[string][]int, len(m.cap)),
+		}
+		for k, v := range cap {
+			e.t.cap[k] = make([]int, len(v))
+			copy(e.t.cap[k], v)
+		}
+	case opLineBegin:
+		if pos == 0 {
+			m.add(list, pc+1, pos, next, cap)
+		}
+	case opLineEnd:
+		if !next {
+			m.add(list, pc+1, pos, next, cap)
+		}
+	case opCapStart, opCapEnd:
+		ocap := make(map[string][]int, len(m.cap))
+		for k, v := range cap {
+			ocap[k] = make([]int, len(v))
+			copy(ocap[k], v)
+		}
+		ocap[op.name] = append(ocap[op.name], pos)
+		m.add(list, pc+1, pos, next, ocap)
+	case opSplit:
+		m.add(list, pc+1, pos, next, cap)
+		m.add(list, op.i, pos, next, cap)
+	case opJmp:
+		m.add(list, op.i, pos, next, cap)
+	case opJmpIfNotDefined:
+		m.add(list, pc+1, pos, next, cap)
+		m.add(list, op.i, pos, next, cap)
+	case opJmpIfNotFirst:
+		m.add(list, pc+1, pos, next, cap)
+		m.add(list, op.i, pos, next, cap)
+	case opJmpIfNotEmpty:
+		m.add(list, op.i, pos, next, cap)
+		m.add(list, pc+1, pos, next, cap)
+	case opNoop:
+		m.add(list, pc+1, pos, next, cap)
+	}
+}
+
+func (m *matcher) step(clist *threadList, nlist *threadList, r rune, pos int, nextPos int, next bool) {
+	debug.Printf("===== %q =====", string(r))
+	for i := 0; i < len(clist.dense); i++ {
+		e := clist.dense[i]
+		if debug {
+			var buf bytes.Buffer
+			dumpProg(&buf, m.prog, e.pc)
+			debug.Printf("\n%s", buf.String())
+		}
+		if e.t == nil {
+			continue
+		}
+
+		t := e.t
+		op := t.op
+		switch op.code {
+		default:
+			panic("unhandled opcode")
+		case opRune:
+			if op.r == r {
+				m.add(nlist, e.pc+1, nextPos, next, t.cap)
+			}
+		case opRuneClass:
+			ret := false
+			if !ret && op.rc&runeClassU == runeClassU {
+				ret = ret || unicode.Is(rangeUnreserved, r)
+			}
+			if !ret && op.rc&runeClassR == runeClassR {
+				ret = ret || unicode.Is(rangeReserved, r)
+			}
+			if !ret && op.rc&runeClassPctE == runeClassPctE {
+				ret = ret || unicode.Is(unicode.ASCII_Hex_Digit, r)
+			}
+			if ret {
+				m.add(nlist, e.pc+1, nextPos, next, t.cap)
+			}
+		case opEnd:
+			m.matched = true
+			for k, v := range t.cap {
+				m.cap[k] = make([]int, len(v))
+				copy(m.cap[k], v)
+			}
+			clist.dense = clist.dense[:0]
+		}
+	}
+	clist.dense = clist.dense[:0]
+}
+
+func (m *matcher) match() bool {
+	pos := 0
+	clist, nlist := &m.list1, &m.list2
+	for {
+		if len(clist.dense) == 0 && m.matched {
+			break
+		}
+		r, width, next := m.at(pos)
+		if !m.matched {
+			m.add(clist, 0, pos, next, m.cap)
+		}
+		m.step(clist, nlist, r, pos, pos+width, next)
+
+		if width < 1 {
+			break
+		}
+		pos += width
+
+		clist, nlist = nlist, clist
+	}
+	return m.matched
+}
+
+func (tmpl *Template) Match(expansion string) Values {
+	tmpl.mu.Lock()
+	if tmpl.prog == nil {
+		c := compiler{}
+		c.init()
+		c.compile(tmpl)
+		tmpl.prog = c.prog
+	}
+	prog := tmpl.prog
+	tmpl.mu.Unlock()
+
+	n := len(prog.op)
+	m := matcher{
+		prog: prog,
+		list1: threadList{
+			dense:  make([]threadEntry, 0, n),
+			sparse: make([]uint32, n),
+		},
+		list2: threadList{
+			dense:  make([]threadEntry, 0, n),
+			sparse: make([]uint32, n),
+		},
+		cap:   make(map[string][]int, prog.numCap),
+		input: expansion,
+	}
+	if !m.match() {
+		return nil
+	}
+
+	match := make(Values, len(m.cap))
+	for name, indices := range m.cap {
+		v := Value{V: make([]string, len(indices)/2)}
+		for i := range v.V {
+			v.V[i] = pctDecode(expansion[indices[2*i]:indices[2*i+1]])
+		}
+		if len(v.V) == 1 {
+			v.T = ValueTypeString
+		} else {
+			v.T = ValueTypeList
+		}
+		match[name] = v
+	}
+	return match
+}

vendor/github.com/yosida95/uritemplate/v3/parse.go

@@ -0,0 +1,277 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"fmt"
+	"unicode"
+	"unicode/utf8"
+)
+
+type parseOp int
+
+const (
+	parseOpSimple parseOp = iota
+	parseOpPlus
+	parseOpCrosshatch
+	parseOpDot
+	parseOpSlash
+	parseOpSemicolon
+	parseOpQuestion
+	parseOpAmpersand
+)
+
+var (
+	rangeVarchar = &unicode.RangeTable{
+		R16: []unicode.Range16{
+			{Lo: 0x0030, Hi: 0x0039, Stride: 1}, // '0' - '9'
+			{Lo: 0x0041, Hi: 0x005A, Stride: 1}, // 'A' - 'Z'
+			{Lo: 0x005F, Hi: 0x005F, Stride: 1}, // '_'
+			{Lo: 0x0061, Hi: 0x007A, Stride: 1}, // 'a' - 'z'
+		},
+		LatinOffset: 4,
+	}
+	rangeLiterals = &unicode.RangeTable{
+		R16: []unicode.Range16{
+			{Lo: 0x0021, Hi: 0x0021, Stride: 1}, // '!'
+			{Lo: 0x0023, Hi: 0x0024, Stride: 1}, // '#' - '$'
+			{Lo: 0x0026, Hi: 0x003B, Stride: 1}, // '&' ''' '(' - ';'. '''/27 used to be excluded but an errata is in the review process https://www.rfc-editor.org/errata/eid6937
+			{Lo: 0x003D, Hi: 0x003D, Stride: 1}, // '='
+			{Lo: 0x003F, Hi: 0x005B, Stride: 1}, // '?' - '['
+			{Lo: 0x005D, Hi: 0x005D, Stride: 1}, // ']'
+			{Lo: 0x005F, Hi: 0x005F, Stride: 1}, // '_'
+			{Lo: 0x0061, Hi: 0x007A, Stride: 1}, // 'a' - 'z'
+			{Lo: 0x007E, Hi: 0x007E, Stride: 1}, // '~'
+			{Lo: 0x00A0, Hi: 0xD7FF, Stride: 1}, // ucschar
+			{Lo: 0xE000, Hi: 0xF8FF, Stride: 1}, // iprivate
+			{Lo: 0xF900, Hi: 0xFDCF, Stride: 1}, // ucschar
+			{Lo: 0xFDF0, Hi: 0xFFEF, Stride: 1}, // ucschar
+		},
+		R32: []unicode.Range32{
+			{Lo: 0x00010000, Hi: 0x0001FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00020000, Hi: 0x0002FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00030000, Hi: 0x0003FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00040000, Hi: 0x0004FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00050000, Hi: 0x0005FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00060000, Hi: 0x0006FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00070000, Hi: 0x0007FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00080000, Hi: 0x0008FFFD, Stride: 1}, // ucschar
+			{Lo: 0x00090000, Hi: 0x0009FFFD, Stride: 1}, // ucschar
+			{Lo: 0x000A0000, Hi: 0x000AFFFD, Stride: 1}, // ucschar
+			{Lo: 0x000B0000, Hi: 0x000BFFFD, Stride: 1}, // ucschar
+			{Lo: 0x000C0000, Hi: 0x000CFFFD, Stride: 1}, // ucschar
+			{Lo: 0x000D0000, Hi: 0x000DFFFD, Stride: 1}, // ucschar
+			{Lo: 0x000E1000, Hi: 0x000EFFFD, Stride: 1}, // ucschar
+			{Lo: 0x000F0000, Hi: 0x000FFFFD, Stride: 1}, // iprivate
+			{Lo: 0x00100000, Hi: 0x0010FFFD, Stride: 1}, // iprivate
+		},
+		LatinOffset: 10,
+	}
+)
+
+type parser struct {
+	r     string
+	start int
+	stop  int
+	state parseState
+}
+
+func (p *parser) errorf(i rune, format string, a ...interface{}) error {
+	return fmt.Errorf("%s: %s%s", fmt.Sprintf(format, a...), p.r[0:p.stop], string(i))
+}
+
+func (p *parser) rune() (rune, int) {
+	r, size := utf8.DecodeRuneInString(p.r[p.stop:])
+	if r != utf8.RuneError {
+		p.stop += size
+	}
+	return r, size
+}
+
+func (p *parser) unread(r rune) {
+	p.stop -= utf8.RuneLen(r)
+}
+
+type parseState int
+
+const (
+	parseStateDefault = parseState(iota)
+	parseStateOperator
+	parseStateVarList
+	parseStateVarName
+	parseStatePrefix
+)
+
+func (p *parser) setState(state parseState) {
+	p.state = state
+	p.start = p.stop
+}
+
+func (p *parser) parseURITemplate() (*Template, error) {
+	tmpl := Template{
+		raw:   p.r,
+		exprs: []template{},
+	}
+
+	var exp *expression
+	for {
+		r, size := p.rune()
+		if r == utf8.RuneError {
+			if size == 0 {
+				if p.state != parseStateDefault {
+					return nil, p.errorf('_', "incomplete expression")
+				}
+				if p.start < p.stop {
+					tmpl.exprs = append(tmpl.exprs, literals(p.r[p.start:p.stop]))
+				}
+				return &tmpl, nil
+			}
+			return nil, p.errorf('_', "invalid UTF-8 sequence")
+		}
+
+		switch p.state {
+		case parseStateDefault:
+			switch r {
+			case '{':
+				if stop := p.stop - size; stop > p.start {
+					tmpl.exprs = append(tmpl.exprs, literals(p.r[p.start:stop]))
+				}
+				exp = &expression{}
+				tmpl.exprs = append(tmpl.exprs, exp)
+				p.setState(parseStateOperator)
+			case '%':
+				p.unread(r)
+				if err := p.consumeTriplet(); err != nil {
+					return nil, err
+				}
+			default:
+				if !unicode.Is(rangeLiterals, r) {
+					p.unread(r)
+					return nil, p.errorf('_', "unacceptable character (hint: use %%XX encoding)")
+				}
+			}
+		case parseStateOperator:
+			switch r {
+			default:
+				p.unread(r)
+				exp.op = parseOpSimple
+			case '+':
+				exp.op = parseOpPlus
+			case '#':
+				exp.op = parseOpCrosshatch
+			case '.':
+				exp.op = parseOpDot
+			case '/':
+				exp.op = parseOpSlash
+			case ';':
+				exp.op = parseOpSemicolon
+			case '?':
+				exp.op = parseOpQuestion
+			case '&':
+				exp.op = parseOpAmpersand
+			case '=', ',', '!', '@', '|': // op-reserved
+				return nil, p.errorf('|', "unimplemented operator (op-reserved)")
+			}
+			p.setState(parseStateVarName)
+		case parseStateVarList:
+			switch r {
+			case ',':
+				p.setState(parseStateVarName)
+			case '}':
+				exp.init()
+				p.setState(parseStateDefault)
+			default:
+				p.unread(r)
+				return nil, p.errorf('_', "unrecognized value modifier")
+			}
+		case parseStateVarName:
+			switch r {
+			case ':', '*':
+				name := p.r[p.start : p.stop-size]
+				if !isValidVarname(name) {
+					return nil, p.errorf('|', "unacceptable variable name")
+				}
+				explode := r == '*'
+				exp.vars = append(exp.vars, varspec{
+					name:    name,
+					explode: explode,
+				})
+				if explode {
+					p.setState(parseStateVarList)
+				} else {
+					p.setState(parseStatePrefix)
+				}
+			case ',', '}':
+				p.unread(r)
+				name := p.r[p.start:p.stop]
+				if !isValidVarname(name) {
+					return nil, p.errorf('|', "unacceptable variable name")
+				}
+				exp.vars = append(exp.vars, varspec{
+					name: name,
+				})
+				p.setState(parseStateVarList)
+			case '%':
+				p.unread(r)
+				if err := p.consumeTriplet(); err != nil {
+					return nil, err
+				}
+			case '.':
+				if dot := p.stop - size; dot == p.start || p.r[dot-1] == '.' {
+					return nil, p.errorf('|', "unacceptable variable name")
+				}
+			default:
+				if !unicode.Is(rangeVarchar, r) {
+					p.unread(r)
+					return nil, p.errorf('_', "unacceptable variable name")
+				}
+			}
+		case parseStatePrefix:
+			spec := &(exp.vars[len(exp.vars)-1])
+			switch {
+			case '0' <= r && r <= '9':
+				spec.maxlen *= 10
+				spec.maxlen += int(r - '0')
+				if spec.maxlen == 0 || spec.maxlen > 9999 {
+					return nil, p.errorf('|', "max-length must be (0, 9999]")
+				}
+			default:
+				p.unread(r)
+				if spec.maxlen == 0 {
+					return nil, p.errorf('_', "max-length must be (0, 9999]")
+				}
+				p.setState(parseStateVarList)
+			}
+		default:
+			p.unread(r)
+			panic(p.errorf('_', "unhandled parseState(%d)", p.state))
+		}
+	}
+}
+
+func isValidVarname(name string) bool {
+	if l := len(name); l == 0 || name[0] == '.' || name[l-1] == '.' {
+		return false
+	}
+	for i := 1; i < len(name)-1; i++ {
+		switch c := name[i]; c {
+		case '.':
+			if name[i-1] == '.' {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func (p *parser) consumeTriplet() error {
+	if len(p.r)-p.stop < 3 || p.r[p.stop] != '%' || !ishex(p.r[p.stop+1]) || !ishex(p.r[p.stop+2]) {
+		return p.errorf('_', "incomplete pct-encodeed")
+	}
+	p.stop += 3
+	return nil
+}

vendor/github.com/yosida95/uritemplate/v3/prog.go

@@ -0,0 +1,130 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"bytes"
+	"strconv"
+)
+
+type progOpcode uint16
+
+const (
+	// match
+	opRune progOpcode = iota
+	opRuneClass
+	opLineBegin
+	opLineEnd
+	// capture
+	opCapStart
+	opCapEnd
+	// stack
+	opSplit
+	opJmp
+	opJmpIfNotDefined
+	opJmpIfNotEmpty
+	opJmpIfNotFirst
+	// result
+	opEnd
+	// fake
+	opNoop
+	opcodeMax
+)
+
+var opcodeNames = []string{
+	// match
+	"opRune",
+	"opRuneClass",
+	"opLineBegin",
+	"opLineEnd",
+	// capture
+	"opCapStart",
+	"opCapEnd",
+	// stack
+	"opSplit",
+	"opJmp",
+	"opJmpIfNotDefined",
+	"opJmpIfNotEmpty",
+	"opJmpIfNotFirst",
+	// result
+	"opEnd",
+}
+
+func (code progOpcode) String() string {
+	if code >= opcodeMax {
+		return ""
+	}
+	return opcodeNames[code]
+}
+
+type progOp struct {
+	code progOpcode
+	r    rune
+	rc   runeClass
+	i    uint32
+
+	name string
+}
+
+func dumpProgOp(b *bytes.Buffer, op *progOp) {
+	b.WriteString(op.code.String())
+	switch op.code {
+	case opRune:
+		b.WriteString("(")
+		b.WriteString(strconv.QuoteToASCII(string(op.r)))
+		b.WriteString(")")
+	case opRuneClass:
+		b.WriteString("(")
+		b.WriteString(op.rc.String())
+		b.WriteString(")")
+	case opCapStart, opCapEnd:
+		b.WriteString("(")
+		b.WriteString(strconv.QuoteToASCII(op.name))
+		b.WriteString(")")
+	case opSplit:
+		b.WriteString(" -> ")
+		b.WriteString(strconv.FormatInt(int64(op.i), 10))
+	case opJmp, opJmpIfNotFirst:
+		b.WriteString(" -> ")
+		b.WriteString(strconv.FormatInt(int64(op.i), 10))
+	case opJmpIfNotDefined, opJmpIfNotEmpty:
+		b.WriteString("(")
+		b.WriteString(strconv.QuoteToASCII(op.name))
+		b.WriteString(")")
+		b.WriteString(" -> ")
+		b.WriteString(strconv.FormatInt(int64(op.i), 10))
+	}
+}
+
+type prog struct {
+	op     []progOp
+	numCap int
+}
+
+func dumpProg(b *bytes.Buffer, prog *prog, pc uint32) {
+	for i := range prog.op {
+		op := prog.op[i]
+
+		pos := strconv.Itoa(i)
+		if uint32(i) == pc {
+			pos = "*" + pos
+		}
+		b.WriteString("    "[len(pos):])
+		b.WriteString(pos)
+
+		b.WriteByte('\t')
+		dumpProgOp(b, &op)
+
+		b.WriteByte('\n')
+	}
+}
+
+func (p *prog) String() string {
+	b := bytes.Buffer{}
+	dumpProg(&b, p, 0)
+	return b.String()
+}

vendor/github.com/yosida95/uritemplate/v3/uritemplate.go

@@ -0,0 +1,116 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import (
+	"log"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+var (
+	debug = debugT(false)
+)
+
+type debugT bool
+
+func (t debugT) Printf(format string, v ...interface{}) {
+	if t {
+		log.Printf(format, v...)
+	}
+}
+
+// Template represents a URI Template.
+type Template struct {
+	raw   string
+	exprs []template
+
+	// protects the rest of fields
+	mu       sync.Mutex
+	varnames []string
+	re       *regexp.Regexp
+	prog     *prog
+}
+
+// New parses and constructs a new Template instance based on the template.
+// New returns an error if the template cannot be recognized.
+func New(template string) (*Template, error) {
+	return (&parser{r: template}).parseURITemplate()
+}
+
+// MustNew panics if the template cannot be recognized.
+func MustNew(template string) *Template {
+	ret, err := New(template)
+	if err != nil {
+		panic(err)
+	}
+	return ret
+}
+
+// Raw returns a raw URI template passed to New in string.
+func (t *Template) Raw() string {
+	return t.raw
+}
+
+// Varnames returns variable names used in the template.
+func (t *Template) Varnames() []string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.varnames != nil {
+		return t.varnames
+	}
+
+	reg := map[string]struct{}{}
+	t.varnames = []string{}
+	for i := range t.exprs {
+		expr, ok := t.exprs[i].(*expression)
+		if !ok {
+			continue
+		}
+		for _, spec := range expr.vars {
+			if _, ok := reg[spec.name]; ok {
+				continue
+			}
+			reg[spec.name] = struct{}{}
+			t.varnames = append(t.varnames, spec.name)
+		}
+	}
+
+	return t.varnames
+}
+
+// Expand returns a URI reference corresponding to the template expanded using the passed variables.
+func (t *Template) Expand(vars Values) (string, error) {
+	var w strings.Builder
+	for i := range t.exprs {
+		expr := t.exprs[i]
+		if err := expr.expand(&w, vars); err != nil {
+			return w.String(), err
+		}
+	}
+	return w.String(), nil
+}
+
+// Regexp converts the template to regexp and returns compiled *regexp.Regexp.
+func (t *Template) Regexp() *regexp.Regexp {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.re != nil {
+		return t.re
+	}
+
+	var b strings.Builder
+	b.WriteByte('^')
+	for _, expr := range t.exprs {
+		expr.regexp(&b)
+	}
+	b.WriteByte('$')
+	t.re = regexp.MustCompile(b.String())
+
+	return t.re
+}

vendor/github.com/yosida95/uritemplate/v3/value.go

@@ -0,0 +1,216 @@
+// Copyright (C) 2016 Kohei YOSHIDA. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of The BSD 3-Clause License
+// that can be found in the LICENSE file.
+
+package uritemplate
+
+import "strings"
+
+// A varname containing pct-encoded characters is not the same variable as
+// a varname with those same characters decoded.
+//
+// -- https://tools.ietf.org/html/rfc6570#section-2.3
+type Values map[string]Value
+
+func (v Values) Set(name string, value Value) {
+	v[name] = value
+}
+
+func (v Values) Get(name string) Value {
+	if v == nil {
+		return Value{}
+	}
+	return v[name]
+}
+
+type ValueType uint8
+
+const (
+	ValueTypeString = iota
+	ValueTypeList
+	ValueTypeKV
+	valueTypeLast
+)
+
+var valueTypeNames = []string{
+	"String",
+	"List",
+	"KV",
+}
+
+func (vt ValueType) String() string {
+	if vt < valueTypeLast {
+		return valueTypeNames[vt]
+	}
+	return ""
+}
+
+type Value struct {
+	T ValueType
+	V []string
+}
+
+func (v Value) String() string {
+	if v.Valid() && v.T == ValueTypeString {
+		return v.V[0]
+	}
+	return ""
+}
+
+func (v Value) List() []string {
+	if v.Valid() && v.T == ValueTypeList {
+		return v.V
+	}
+	return nil
+}
+
+func (v Value) KV() []string {
+	if v.Valid() && v.T == ValueTypeKV {
+		return v.V
+	}
+	return nil
+}
+
+func (v Value) Valid() bool {
+	switch v.T {
+	default:
+		return false
+	case ValueTypeString:
+		return len(v.V) > 0
+	case ValueTypeList:
+		return len(v.V) > 0
+	case ValueTypeKV:
+		return len(v.V) > 0 && len(v.V)%2 == 0
+	}
+}
+
+func (v Value) expand(w *strings.Builder, spec varspec, exp *expression) error {
+	switch v.T {
+	case ValueTypeString:
+		val := v.V[0]
+		var maxlen int
+		if max := len(val); spec.maxlen < 1 || spec.maxlen > max {
+			maxlen = max
+		} else {
+			maxlen = spec.maxlen
+		}
+
+		if exp.named {
+			w.WriteString(spec.name)
+			if val == "" {
+				w.WriteString(exp.ifemp)
+				return nil
+			}
+			w.WriteByte('=')
+		}
+		return exp.escape(w, val[:maxlen])
+	case ValueTypeList:
+		var sep string
+		if spec.explode {
+			sep = exp.sep
+		} else {
+			sep = ","
+		}
+
+		var pre string
+		var preifemp string
+		if spec.explode && exp.named {
+			pre = spec.name + "="
+			preifemp = spec.name + exp.ifemp
+		}
+
+		if !spec.explode && exp.named {
+			w.WriteString(spec.name)
+			w.WriteByte('=')
+		}
+		for i := range v.V {
+			val := v.V[i]
+			if i > 0 {
+				w.WriteString(sep)
+			}
+			if val == "" {
+				w.WriteString(preifemp)
+				continue
+			}
+			w.WriteString(pre)
+
+			if err := exp.escape(w, val); err != nil {
+				return err
+			}
+		}
+	case ValueTypeKV:
+		var sep string
+		var kvsep string
+		if spec.explode {
+			sep = exp.sep
+			kvsep = "="
+		} else {
+			sep = ","
+			kvsep = ","
+		}
+
+		var ifemp string
+		var kescape escapeFunc
+		if spec.explode && exp.named {
+			ifemp = exp.ifemp
+			kescape = escapeLiteral
+		} else {
+			ifemp = ","
+			kescape = exp.escape
+		}
+
+		if !spec.explode && exp.named {
+			w.WriteString(spec.name)
+			w.WriteByte('=')
+		}
+
+		for i := 0; i < len(v.V); i += 2 {
+			if i > 0 {
+				w.WriteString(sep)
+			}
+			if err := kescape(w, v.V[i]); err != nil {
+				return err
+			}
+			if v.V[i+1] == "" {
+				w.WriteString(ifemp)
+				continue
+			}
+			w.WriteString(kvsep)
+
+			if err := exp.escape(w, v.V[i+1]); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// String returns Value that represents string.
+func String(v string) Value {
+	return Value{
+		T: ValueTypeString,
+		V: []string{v},
+	}
+}
+
+// List returns Value that represents list.
+func List(v ...string) Value {
+	return Value{
+		T: ValueTypeList,
+		V: v,
+	}
+}
+
+// KV returns Value that represents associative list.
+// KV panics if len(kv) is not even.
+func KV(kv ...string) Value {
+	if len(kv)%2 != 0 {
+		panic("uritemplate.go: count of the kv must be even number")
+	}
+	return Value{
+		T: ValueTypeKV,
+		V: kv,
+	}
+}