func HTMLEscaper(args ...interface{}) string {
	return template.HTMLEscaper(args...)
}
HTMLEscaper returns the escaped HTML equivalent of the textual
representation of its arguments.
package template
import (
	"bytes"
	"fmt"
	"html"
	"io"
	"text/template"
	"text/template/parse"
)
func escapeTemplate(tmpl *Template, node parse.Node, name string) error {
	c, _ := tmpl.esc.escapeTree(context{}, node, name, 0)
	var err error
	if c.err != nil {
		err, c.err.Name = c.err, name
	} else if c.state != stateText {
		err = &Error{ErrEndContext, nil, name, 0, fmt.Sprintf("ends in a non-text context: %v", c)}
	}
	if err != nil {
		if t := tmpl.set[name]; t != nil {
			t.escapeErr = err
			t.text.Tree = nil
			t.Tree = nil
		}
		return err
	}
	tmpl.esc.commit()
	if t := tmpl.set[name]; t != nil {
		t.escapeErr = escapeOK
		t.Tree = t.text.Tree
	}
	return nil
}
func evalArgs(args ...interface{}) string {
	if len(args) == 1 {
		if s, ok := args[0].(string); ok {
			return s
		}
	}
	for i, arg := range args {
		args[i] = indirectToStringerOrError(arg)
	}
	return fmt.Sprint(args...)
}
var funcMap = template.FuncMap{
	"_html_template_attrescaper":     attrEscaper,
	"_html_template_commentescaper":  commentEscaper,
	"_html_template_cssescaper":      cssEscaper,
	"_html_template_cssvaluefilter":  cssValueFilter,
	"_html_template_htmlnamefilter":  htmlNameFilter,
	"_html_template_htmlescaper":     htmlEscaper,
	"_html_template_jsregexpescaper": jsRegexpEscaper,
	"_html_template_jsstrescaper":    jsStrEscaper,
	"_html_template_jsvalescaper":    jsValEscaper,
	"_html_template_nospaceescaper":  htmlNospaceEscaper,
	"_html_template_rcdataescaper":   rcdataEscaper,
	"_html_template_urlescaper":      urlEscaper,
	"_html_template_urlfilter":       urlFilter,
	"_html_template_urlnormalizer":   urlNormalizer,
	"_eval_args_":                    evalArgs,
}
type escaper struct {
	ns *nameSpace
	output map[string]context
	derived map[string]*template.Template
	called map[string]bool
	actionNodeEdits   map[*parse.ActionNode][]string
	templateNodeEdits map[*parse.TemplateNode]string
	textNodeEdits     map[*parse.TextNode][]byte
}
func makeEscaper(n *nameSpace) escaper {
	return escaper{
		n,
		map[string]context{},
		map[string]*template.Template{},
		map[string]bool{},
		map[*parse.ActionNode][]string{},
		map[*parse.TemplateNode]string{},
		map[*parse.TextNode][]byte{},
	}
}
const filterFailsafe = "ZgotmplZ"
func (e *escaper) escape(c context, n parse.Node) context {
	switch n := n.(type) {
	case *parse.ActionNode:
		return e.escapeAction(c, n)
	case *parse.IfNode:
		return e.escapeBranch(c, &n.BranchNode, "if")
	case *parse.ListNode:
		return e.escapeList(c, n)
	case *parse.RangeNode:
		return e.escapeBranch(c, &n.BranchNode, "range")
	case *parse.TemplateNode:
		return e.escapeTemplate(c, n)
	case *parse.TextNode:
		return e.escapeText(c, n)
	case *parse.WithNode:
		return e.escapeBranch(c, &n.BranchNode, "with")
	}
	panic("escaping " + n.String() + " is unimplemented")
}
func (e *escaper) escapeAction(c context, n *parse.ActionNode) context {
	if len(n.Pipe.Decl) != 0 {
		return c
	}
	c = nudge(c)
	for pos, idNode := range n.Pipe.Cmds {
		node, ok := idNode.Args[0].(*parse.IdentifierNode)
		if !ok {
			continue
		}
		ident := node.Ident
		if _, ok := predefinedEscapers[ident]; ok {
			if pos < len(n.Pipe.Cmds)-1 ||
				c.state == stateAttr && c.delim == delimSpaceOrTagEnd && ident == "html" {
				return context{
					state: stateError,
					err:   errorf(ErrPredefinedEscaper, n, n.Line, "predefined escaper %q disallowed in template", ident),
				}
			}
		}
	}
	s := make([]string, 0, 3)
	switch c.state {
	case stateError:
		return c
	case stateURL, stateCSSDqStr, stateCSSSqStr, stateCSSDqURL, stateCSSSqURL, stateCSSURL:
		switch c.urlPart {
		case urlPartNone:
			s = append(s, "_html_template_urlfilter")
			fallthrough
		case urlPartPreQuery:
			switch c.state {
			case stateCSSDqStr, stateCSSSqStr:
				s = append(s, "_html_template_cssescaper")
			default:
				s = append(s, "_html_template_urlnormalizer")
			}
		case urlPartQueryOrFrag:
			s = append(s, "_html_template_urlescaper")
		case urlPartUnknown:
			return context{
				state: stateError,
				err:   errorf(ErrAmbigContext, n, n.Line, "%s appears in an ambiguous context within a URL", n),
			}
		default:
			panic(c.urlPart.String())
		}
	case stateJS:
		s = append(s, "_html_template_jsvalescaper")
		c.jsCtx = jsCtxDivOp
	case stateJSDqStr, stateJSSqStr:
		s = append(s, "_html_template_jsstrescaper")
	case stateJSRegexp:
		s = append(s, "_html_template_jsregexpescaper")
	case stateCSS:
		s = append(s, "_html_template_cssvaluefilter")
	case stateText:
		s = append(s, "_html_template_htmlescaper")
	case stateRCDATA:
		s = append(s, "_html_template_rcdataescaper")
	case stateAttr:
	case stateAttrName, stateTag:
		c.state = stateAttrName
		s = append(s, "_html_template_htmlnamefilter")
	default:
		if isComment(c.state) {
			s = append(s, "_html_template_commentescaper")
		} else {
			panic("unexpected state " + c.state.String())
		}
	}
	switch c.delim {
	case delimNone:
	case delimSpaceOrTagEnd:
		s = append(s, "_html_template_nospaceescaper")
	default:
		s = append(s, "_html_template_attrescaper")
	}
	e.editActionNode(n, s)
	return c
}
func ensurePipelineContains(p *parse.PipeNode, s []string) {
	if len(s) == 0 {
		return
	}
	pipelineLen := len(p.Cmds)
	if pipelineLen > 0 {
		lastCmd := p.Cmds[pipelineLen-1]
		if idNode, ok := lastCmd.Args[0].(*parse.IdentifierNode); ok {
			if esc := idNode.Ident; predefinedEscapers[esc] {
				if len(p.Cmds) == 1 && len(lastCmd.Args) > 1 {
					lastCmd.Args[0] = parse.NewIdentifier("_eval_args_").SetTree(nil).SetPos(lastCmd.Args[0].Position())
					p.Cmds = appendCmd(p.Cmds, newIdentCmd(esc, p.Position()))
					pipelineLen++
				}
				dup := false
				for i, escaper := range s {
					if escFnsEq(esc, escaper) {
						s[i] = idNode.Ident
						dup = true
					}
				}
				if dup {
					pipelineLen--
				}
			}
		}
	}
	newCmds := make([]*parse.CommandNode, pipelineLen, pipelineLen+len(s))
	copy(newCmds, p.Cmds)
	for _, name := range s {
		newCmds = appendCmd(newCmds, newIdentCmd(name, p.Position()))
	}
	p.Cmds = newCmds
}
var predefinedEscapers = map[string]bool{
	"html":     true,
	"urlquery": true,
}
var equivEscapers = map[string]string{
	"_html_template_attrescaper":   "html",
	"_html_template_htmlescaper":   "html",
	"_html_template_rcdataescaper": "html",
	"_html_template_urlescaper": "urlquery",
	"_html_template_urlnormalizer": "urlquery",
}
func escFnsEq(a, b string) bool {
	if e := equivEscapers[a]; e != "" {
		a = e
	}
	if e := equivEscapers[b]; e != "" {
		b = e
	}
	return a == b
}
var redundantFuncs = map[string]map[string]bool{
	"_html_template_commentescaper": {
		"_html_template_attrescaper":    true,
		"_html_template_nospaceescaper": true,
		"_html_template_htmlescaper":    true,
	},
	"_html_template_cssescaper": {
		"_html_template_attrescaper": true,
	},
	"_html_template_jsregexpescaper": {
		"_html_template_attrescaper": true,
	},
	"_html_template_jsstrescaper": {
		"_html_template_attrescaper": true,
	},
	"_html_template_urlescaper": {
		"_html_template_urlnormalizer": true,
	},
}
func appendCmd(cmds []*parse.CommandNode, cmd *parse.CommandNode) []*parse.CommandNode {
	if n := len(cmds); n != 0 {
		last, okLast := cmds[n-1].Args[0].(*parse.IdentifierNode)
		next, okNext := cmd.Args[0].(*parse.IdentifierNode)
		if okLast && okNext && redundantFuncs[last.Ident][next.Ident] {
			return cmds
		}
	}
	return append(cmds, cmd)
}
func indexOfStr(s string, strs []string, eq func(a, b string) bool) int {
	for i, t := range strs {
		if eq(s, t) {
			return i
		}
	}
	return -1
}
func newIdentCmd(identifier string, pos parse.Pos) *parse.CommandNode {
	return &parse.CommandNode{
		NodeType: parse.NodeCommand,
		Args:     []parse.Node{parse.NewIdentifier(identifier).SetTree(nil).SetPos(pos)},  
	}
}
func nudge(c context) context {
	switch c.state {
	case stateTag:
		c.state = stateAttrName
	case stateBeforeValue:
		c.state, c.delim, c.attr = attrStartStates[c.attr], delimSpaceOrTagEnd, attrNone
	case stateAfterName:
		c.state, c.attr = stateAttrName, attrNone
	}
	return c
}
func join(a, b context, node parse.Node, nodeName string) context {
	if a.state == stateError {
		return a
	}
	if b.state == stateError {
		return b
	}
	if a.eq(b) {
		return a
	}
	c := a
	c.urlPart = b.urlPart
	if c.eq(b) {
		c.urlPart = urlPartUnknown
		return c
	}
	c = a
	c.jsCtx = b.jsCtx
	if c.eq(b) {
		c.jsCtx = jsCtxUnknown
		return c
	}
	if c, d := nudge(a), nudge(b); !(c.eq(a) && d.eq(b)) {
		if e := join(c, d, node, nodeName); e.state != stateError {
			return e
		}
	}
	return context{
		state: stateError,
		err:   errorf(ErrBranchEnd, node, 0, "{{%s}} branches end in different contexts: %v, %v", nodeName, a, b),
	}
}
func (e *escaper) escapeBranch(c context, n *parse.BranchNode, nodeName string) context {
	c0 := e.escapeList(c, n.List)
	if nodeName == "range" && c0.state != stateError {
		c1, _ := e.escapeListConditionally(c0, n.List, nil)
		c0 = join(c0, c1, n, nodeName)
		if c0.state == stateError {
			c0.err.Line = n.Line
			c0.err.Description = "on range loop re-entry: " + c0.err.Description
			return c0
		}
	}
	c1 := e.escapeList(c, n.ElseList)
	return join(c0, c1, n, nodeName)
}
func (e *escaper) escapeList(c context, n *parse.ListNode) context {
	if n == nil {
		return c
	}
	for _, m := range n.Nodes {
		c = e.escape(c, m)
	}
	return c
}
func (e *escaper) escapeListConditionally(c context, n *parse.ListNode, filter func(*escaper, context) bool) (context, bool) {
	e1 := makeEscaper(e.ns)
	for k, v := range e.output {
		e1.output[k] = v
	}
	c = e1.escapeList(c, n)
	ok := filter != nil && filter(&e1, c)
	if ok {
		for k, v := range e1.output {
			e.output[k] = v
		}
		for k, v := range e1.derived {
			e.derived[k] = v
		}
		for k, v := range e1.called {
			e.called[k] = v
		}
		for k, v := range e1.actionNodeEdits {
			e.editActionNode(k, v)
		}
		for k, v := range e1.templateNodeEdits {
			e.editTemplateNode(k, v)
		}
		for k, v := range e1.textNodeEdits {
			e.editTextNode(k, v)
		}
	}
	return c, ok
}
func (e *escaper) escapeTemplate(c context, n *parse.TemplateNode) context {
	c, name := e.escapeTree(c, n, n.Name, n.Line)
	if name != n.Name {
		e.editTemplateNode(n, name)
	}
	return c
}
func (e *escaper) escapeTree(c context, node parse.Node, name string, line int) (context, string) {
	dname := c.mangle(name)
	e.called[dname] = true
	if out, ok := e.output[dname]; ok {
		return out, dname
	}
	t := e.template(name)
	if t == nil {
		if e.ns.set[name] != nil {
			return context{
				state: stateError,
				err:   errorf(ErrNoSuchTemplate, node, line, "%q is an incomplete or empty template", name),
			}, dname
		}
		return context{
			state: stateError,
			err:   errorf(ErrNoSuchTemplate, node, line, "no such template %q", name),
		}, dname
	}
	if dname != name {
		dt := e.template(dname)
		if dt == nil {
			dt = template.New(dname)
			dt.Tree = &parse.Tree{Name: dname, Root: t.Root.CopyList()}
			e.derived[dname] = dt
		}
		t = dt
	}
	return e.computeOutCtx(c, t), dname
}
func (e *escaper) computeOutCtx(c context, t *template.Template) context {
	c1, ok := e.escapeTemplateBody(c, t)
	if !ok {
		if c2, ok2 := e.escapeTemplateBody(c1, t); ok2 {
			c1, ok = c2, true
		}
	}
	if !ok && c1.state != stateError {
		return context{
			state: stateError,
			err:   errorf(ErrOutputContext, t.Tree.Root, 0, "cannot compute output context for template %s", t.Name()),
		}
	}
	return c1
}
func (e *escaper) escapeTemplateBody(c context, t *template.Template) (context, bool) {
	filter := func(e1 *escaper, c1 context) bool {
		if c1.state == stateError {
			return false
		}
		if !e1.called[t.Name()] {
			return true
		}
		return c.eq(c1)
	}
	e.output[t.Name()] = c
	return e.escapeListConditionally(c, t.Tree.Root, filter)
}
var delimEnds = [...]string{
	delimDoubleQuote: `"`,
	delimSingleQuote: "'",
	// Determined empirically by running the below in various browsers.
	// var div = document.createElement("DIV");
	// for (var i = 0; i < 0x10000; ++i) {
	//   div.innerHTML = "<span title=x" + String.fromCharCode(i) + "-bar>";
	//   if (div.getElementsByTagName("SPAN")[0].title.indexOf("bar") < 0)
	//     document.write("<p>U+" + i.toString(16));
	// }
	delimSpaceOrTagEnd: " \t\n\f\r>",
}
var doctypeBytes = []byte("<!DOCTYPE")
// escapeText escapes a text template node.
func (e *escaper) escapeText(c context, n *parse.TextNode) context {
	s, written, i, b := n.Text, 0, 0, new(bytes.Buffer)
	for i != len(s) {
		c1, nread := contextAfterText(c, s[i:])
		i1 := i + nread
		if c.state == stateText || c.state == stateRCDATA {
			end := i1
			if c1.state != c.state {
				for j := end - 1; j >= i; j-- {
					if s[j] == '<' {
						end = j
						break
					}
				}
			}
			for j := i; j < end; j++ {
				if s[j] == '<' && !bytes.HasPrefix(bytes.ToUpper(s[j:]), doctypeBytes) {
					b.Write(s[written:j])
					b.WriteString("&lt;")
					written = j + 1
				}
			}
		} else if isComment(c.state) && c.delim == delimNone {
			switch c.state {
			case stateJSBlockCmt:
				// http://es5.github.com/#x7.4:
				// "Comments behave like white space and are
				// discarded except that, if a MultiLineComment
				// contains a line terminator character, then
				// the entire comment is considered to be a
				// LineTerminator for purposes of parsing by
				// the syntactic grammar."
				if bytes.ContainsAny(s[written:i1], "\n\r\u2028\u2029") {
					b.WriteByte('\n')
				} else {
					b.WriteByte(' ')
				}
			case stateCSSBlockCmt:
				b.WriteByte(' ')
			}
			written = i1
		}
		if c.state != c1.state && isComment(c1.state) && c1.delim == delimNone {
			// Preserve the portion between written and the comment start.
			cs := i1 - 2
			if c1.state == stateHTMLCmt {
				// "<!--" instead of "/*" or "//"
				cs -= 2
			}
			b.Write(s[written:cs])
			written = i1
		}
		if i == i1 && c.state == c1.state {
			panic(fmt.Sprintf("infinite loop from %v to %v on %q..%q", c, c1, s[:i], s[i:]))
		}
		c, i = c1, i1
	}
	if written != 0 && c.state != stateError {
		if !isComment(c.state) || c.delim != delimNone {
			b.Write(n.Text[written:])
		}
		e.editTextNode(n, b.Bytes())
	}
	return c
}
// contextAfterText starts in context c, consumes some tokens from the front of
// s, then returns the context after those tokens and the unprocessed suffix.
func contextAfterText(c context, s []byte) (context, int) {
	if c.delim == delimNone {
		c1, i := tSpecialTagEnd(c, s)
		if i == 0 {
			// A special end tag (`</script>`) has been seen and
			// all content preceding it has been consumed.
			return c1, 0
		}
		// Consider all content up to any end tag.
		return transitionFunc[c.state](c, s[:i])
	}
	// We are at the beginning of an attribute value.
	i := bytes.IndexAny(s, delimEnds[c.delim])
	if i == -1 {
		i = len(s)
	}
	if c.delim == delimSpaceOrTagEnd {
		// http://www.w3.org/TR/html5/syntax.html#attribute-value-(unquoted)-state
		// lists the runes below as error characters.
		// Error out because HTML parsers may differ on whether
		// "<a id= onclick=f("     ends inside id's or onclick's value,
		// "<a class=`foo "        ends inside a value,
		// "<a style=font:'Arial'" needs open-quote fixup.
		// IE treats '`' as a quotation character.
		if j := bytes.IndexAny(s[:i], "\"'<=`"); j >= 0 {
			return context{
				state: stateError,
				err:   errorf(ErrBadHTML, nil, 0, "%q in unquoted attr: %q", s[j:j+1], s[:i]),
			}, len(s)
		}
	}
	if i == len(s) {
		// Remain inside the attribute.
		// Decode the value so non-HTML rules can easily handle
		//     <button onclick="alert(&quot;Hi!&quot;)">
		// without having to entity decode token boundaries.
		for u := []byte(html.UnescapeString(string(s))); len(u) != 0; {
			c1, i1 := transitionFunc[c.state](c, u)
			c, u = c1, u[i1:]
		}
		return c, len(s)
	}
	element := c.element
	// If this is a non-JS "type" attribute inside "script" tag, do not treat the contents as JS.
	if c.state == stateAttr && c.element == elementScript && c.attr == attrScriptType && !isJSType(string(s[:i])) {
		element = elementNone
	}
	if c.delim != delimSpaceOrTagEnd {
		// Consume any quote.
		i++
	}
	// On exiting an attribute, we discard all state information
	// except the state and element.
	return context{state: stateTag, element: element}, i
}
// editActionNode records a change to an action pipeline for later commit.
func (e *escaper) editActionNode(n *parse.ActionNode, cmds []string) {
	if _, ok := e.actionNodeEdits[n]; ok {
		panic(fmt.Sprintf("node %s shared between templates", n))
	}
	e.actionNodeEdits[n] = cmds
}
// editTemplateNode records a change to a {{template}} callee for later commit.
func (e *escaper) editTemplateNode(n *parse.TemplateNode, callee string) {
	if _, ok := e.templateNodeEdits[n]; ok {
		panic(fmt.Sprintf("node %s shared between templates", n))
	}
	e.templateNodeEdits[n] = callee
}
// editTextNode records a change to a text node for later commit.
func (e *escaper) editTextNode(n *parse.TextNode, text []byte) {
	if _, ok := e.textNodeEdits[n]; ok {
		panic(fmt.Sprintf("node %s shared between templates", n))
	}
	e.textNodeEdits[n] = text
}
// commit applies changes to actions and template calls needed to contextually
// autoescape content and adds any derived templates to the set.
func (e *escaper) commit() {
	for name := range e.output {
		e.template(name).Funcs(funcMap)
	}
	// Any template from the name space associated with this escaper can be used
	// to add derived templates to the underlying text/template name space.
	tmpl := e.arbitraryTemplate()
	for _, t := range e.derived {
		if _, err := tmpl.text.AddParseTree(t.Name(), t.Tree); err != nil {
			panic("error adding derived template")
		}
	}
	for n, s := range e.actionNodeEdits {
		ensurePipelineContains(n.Pipe, s)
	}
	for n, name := range e.templateNodeEdits {
		n.Name = name
	}
	for n, s := range e.textNodeEdits {
		n.Text = s
	}
	// Reset state that is specific to this commit so that the same changes are
	// not re-applied to the template on subsequent calls to commit.
	e.called = make(map[string]bool)
	e.actionNodeEdits = make(map[*parse.ActionNode][]string)
	e.templateNodeEdits = make(map[*parse.TemplateNode]string)
	e.textNodeEdits = make(map[*parse.TextNode][]byte)
}
// template returns the named template given a mangled template name.
func (e *escaper) template(name string) *template.Template {
	// Any template from the name space associated with this escaper can be used
	// to look up templates in the underlying text/template name space.
	t := e.arbitraryTemplate().text.Lookup(name)
	if t == nil {
		t = e.derived[name]
	}
	return t
}
// arbitraryTemplate returns an arbitrary template from the name space
// associated with e and panics if no templates are found.
func (e *escaper) arbitraryTemplate() *Template {
	for _, t := range e.ns.set {
		return t
	}
	panic("no templates in name space")
}
func HTMLEscape(w io.Writer, b []byte) {
	template.HTMLEscape(w, b)
}
func HTMLEscapeString(s string) string {
	return template.HTMLEscapeString(s)
}