html/atom: sync html table with the current whatwg spec

Some elements and attributes have been removed from the spec,
but are kept here for backwards compatibility.

Also, this makes gen.go support go:generate and write contents into
target files directly.

Finally, this makes `go generate` work on an entire directory.

Change-Id: I8d41840eec69eec1ef08527d8d71786612a3121d
Reviewed-on: https://go-review.googlesource.com/65152
Run-TryBot: Tom Bergan <tombergan@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tom Bergan <tombergan@google.com>

Author: namusyaka

html/atom/gen.go

@@ -4,17 +4,17 @@
 
 // +build ignore
 
-package main
+//go:generate go run gen.go
+//go:generate go run gen.go -test
 
-// This program generates table.go and table_test.go.
-// Invoke as
-//
-//	go run gen.go |gofmt >table.go
-//	go run gen.go -test |gofmt >table_test.go
+package main
 
 import (
+	"bytes"
 	"flag"
 	"fmt"
+	"go/format"
+	"io/ioutil"
 	"math/rand"
 	"os"
 	"sort"
@@ -42,6 +42,18 @@ func identifier(s string) string {
 
 var test = flag.Bool("test", false, "generate table_test.go")
 
+func genFile(name string, buf *bytes.Buffer) {
+	b, err := format.Source(buf.Bytes())
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	if err := ioutil.WriteFile(name, b, 0644); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
 func main() {
 	flag.Parse()
 
@@ -52,32 +64,31 @@ func main() {
 	all = append(all, extra...)
 	sort.Strings(all)
 
-	if *test {
-		fmt.Printf("// generated by go run gen.go -test; DO NOT EDIT\n\n")
-		fmt.Printf("package atom\n\n")
-		fmt.Printf("var testAtomList = []string{\n")
-		for _, s := range all {
-			fmt.Printf("\t%q,\n", s)
-		}
-		fmt.Printf("}\n")
-		return
-	}
-
 	// uniq - lists have dups
-	// compute max len too
-	maxLen := 0
 	w := 0
 	for _, s := range all {
 		if w == 0 || all[w-1] != s {
-			if maxLen < len(s) {
-				maxLen = len(s)
-			}
 			all[w] = s
 			w++
 		}
 	}
 	all = all[:w]
 
+	if *test {
+		var buf bytes.Buffer
+		fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
+		fmt.Fprintln(&buf, "//go:generate go run gen.go -test\n")
+		fmt.Fprintln(&buf, "package atom\n")
+		fmt.Fprintln(&buf, "var testAtomList = []string{")
+		for _, s := range all {
+			fmt.Fprintf(&buf, "\t%q,\n", s)
+		}
+		fmt.Fprintln(&buf, "}")
+
+		genFile("table_test.go", &buf)
+		return
+	}
+
 	// Find hash that minimizes table size.
 	var best *table
 	for i := 0; i < 1000000; i++ {
@@ -163,36 +174,46 @@ func main() {
 		atom[s] = uint32(off<<8 | len(s))
 	}
 
+	var buf bytes.Buffer
 	// Generate the Go code.
-	fmt.Printf("// generated by go run gen.go; DO NOT EDIT\n\n")
-	fmt.Printf("package atom\n\nconst (\n")
+	fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
+	fmt.Fprintln(&buf, "//go:generate go run gen.go\n")
+	fmt.Fprintln(&buf, "package atom\n\nconst (")
+
+	// compute max len
+	maxLen := 0
 	for _, s := range all {
-		fmt.Printf("\t%s Atom = %#x\n", identifier(s), atom[s])
+		if maxLen < len(s) {
+			maxLen = len(s)
+		}
+		fmt.Fprintf(&buf, "\t%s Atom = %#x\n", identifier(s), atom[s])
 	}
-	fmt.Printf(")\n\n")
+	fmt.Fprintln(&buf, ")\n")
 
-	fmt.Printf("const hash0 = %#x\n\n", best.h0)
-	fmt.Printf("const maxAtomLen = %d\n\n", maxLen)
+	fmt.Fprintf(&buf, "const hash0 = %#x\n\n", best.h0)
+	fmt.Fprintf(&buf, "const maxAtomLen = %d\n\n", maxLen)
 
-	fmt.Printf("var table = [1<<%d]Atom{\n", best.k)
+	fmt.Fprintf(&buf, "var table = [1<<%d]Atom{\n", best.k)
 	for i, s := range best.tab {
 		if s == "" {
 			continue
 		}
-		fmt.Printf("\t%#x: %#x, // %s\n", i, atom[s], s)
+		fmt.Fprintf(&buf, "\t%#x: %#x, // %s\n", i, atom[s], s)
 	}
-	fmt.Printf("}\n")
+	fmt.Fprintf(&buf, "}\n")
 	datasize := (1 << best.k) * 4
 
-	fmt.Printf("const atomText =\n")
+	fmt.Fprintln(&buf, "const atomText =")
 	textsize := len(text)
 	for len(text) > 60 {
-		fmt.Printf("\t%q +\n", text[:60])
+		fmt.Fprintf(&buf, "\t%q +\n", text[:60])
 		text = text[60:]
 	}
-	fmt.Printf("\t%q\n\n", text)
+	fmt.Fprintf(&buf, "\t%q\n\n", text)
+
+	genFile("table.go", &buf)
 
-	fmt.Fprintf(os.Stderr, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize)
+	fmt.Fprintf(os.Stdout, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize)
 }
 
 type byLen []string
@@ -285,8 +306,10 @@ func (t *table) push(i uint32, depth int) bool {
 
 // The lists of element names and attribute keys were taken from
 // https://html.spec.whatwg.org/multipage/indices.html#index
-// as of the "HTML Living Standard - Last Updated 21 February 2015" version.
+// as of the "HTML Living Standard - Last Updated 18 September 2017" version.
 
+// "command", "keygen" and "menuitem" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var elements = []string{
 	"a",
 	"abbr",
@@ -349,6 +372,7 @@ var elements = []string{
 	"legend",
 	"li",
 	"link",
+	"main",
 	"map",
 	"mark",
 	"menu",
@@ -364,6 +388,7 @@ var elements = []string{
 	"output",
 	"p",
 	"param",
+	"picture",
 	"pre",
 	"progress",
 	"q",
@@ -375,6 +400,7 @@ var elements = []string{
 	"script",
 	"section",
 	"select",
+	"slot",
 	"small",
 	"source",
 	"span",
@@ -403,14 +429,21 @@ var elements = []string{
 }
 
 // https://html.spec.whatwg.org/multipage/indices.html#attributes-3
-
+//
+// "challenge", "command", "contextmenu", "dropzone", "icon", "keytype", "mediagroup",
+// "radiogroup", "spellcheck", "scoped", "seamless", "sortable" and "sorted" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var attributes = []string{
 	"abbr",
 	"accept",
 	"accept-charset",
 	"accesskey",
 	"action",
+	"allowfullscreen",
+	"allowpaymentrequest",
+	"allowusermedia",
 	"alt",
+	"as",
 	"async",
 	"autocomplete",
 	"autofocus",
@@ -420,6 +453,7 @@ var attributes = []string{
 	"checked",
 	"cite",
 	"class",
+	"color",
 	"cols",
 	"colspan",
 	"command",
@@ -457,6 +491,8 @@ var attributes = []string{
 	"icon",
 	"id",
 	"inputmode",
+	"integrity",
+	"is",
 	"ismap",
 	"itemid",
 	"itemprop",
@@ -481,16 +517,20 @@ var attributes = []string{
 	"multiple",
 	"muted",
 	"name",
+	"nomodule",
+	"nonce",
 	"novalidate",
 	"open",
 	"optimum",
 	"pattern",
 	"ping",
 	"placeholder",
+	"playsinline",
 	"poster",
 	"preload",
 	"radiogroup",
 	"readonly",
+	"referrerpolicy",
 	"rel",
 	"required",
 	"reversed",
@@ -507,10 +547,13 @@ var attributes = []string{
 	"sizes",
 	"sortable",
 	"sorted",
+	"slot",
 	"span",
+	"spellcheck",
 	"src",
 	"srcdoc",
 	"srclang",
+	"srcset",
 	"start",
 	"step",
 	"style",
@@ -520,16 +563,22 @@ var attributes = []string{
 	"translate",
 	"type",
 	"typemustmatch",
+	"updateviacache",
 	"usemap",
 	"value",
 	"width",
+	"workertype",
 	"wrap",
 }
 
+// "onautocomplete", "onautocompleteerror", "onmousewheel",
+// "onshow" and "onsort" have been removed from the spec,
+// but are kept here for backwards compatibility.
 var eventHandlers = []string{
 	"onabort",
 	"onautocomplete",
 	"onautocompleteerror",
+	"onauxclick",
 	"onafterprint",
 	"onbeforeprint",
 	"onbeforeunload",
@@ -541,11 +590,14 @@ var eventHandlers = []string{
 	"onclick",
 	"onclose",
 	"oncontextmenu",
+	"oncopy",
 	"oncuechange",
+	"oncut",
 	"ondblclick",
 	"ondrag",
 	"ondragend",
 	"ondragenter",
+	"ondragexit",
 	"ondragleave",
 	"ondragover",
 	"ondragstart",
@@ -565,18 +617,24 @@ var eventHandlers = []string{
 	"onload",
 	"onloadeddata",
 	"onloadedmetadata",
+	"onloadend",
 	"onloadstart",
 	"onmessage",
+	"onmessageerror",
 	"onmousedown",
+	"onmouseenter",
+	"onmouseleave",
 	"onmousemove",
 	"onmouseout",
 	"onmouseover",
 	"onmouseup",
 	"onmousewheel",
+	"onwheel",
 	"onoffline",
 	"ononline",
 	"onpagehide",
 	"onpageshow",
+	"onpaste",
 	"onpause",
 	"onplay",
 	"onplaying",
@@ -585,7 +643,9 @@ var eventHandlers = []string{
 	"onratechange",
 	"onreset",
 	"onresize",
+	"onrejectionhandled",
 	"onscroll",
+	"onsecuritypolicyviolation",
 	"onseeked",
 	"onseeking",
 	"onselect",
@@ -597,6 +657,7 @@ var eventHandlers = []string{
 	"onsuspend",
 	"ontimeupdate",
 	"ontoggle",
+	"onunhandledrejection",
 	"onunload",
 	"onvolumechange",
 	"onwaiting",