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-rw-r--r--src/pkg/html/parse.go670
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diff --git a/src/pkg/html/parse.go b/src/pkg/html/parse.go
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--- a/src/pkg/html/parse.go
+++ /dev/null
@@ -1,670 +0,0 @@
-// Copyright 2010 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 html
-
-import (
- "io"
- "os"
-)
-
-// A NodeType is the type of a Node.
-type NodeType int
-
-const (
- ErrorNode NodeType = iota
- TextNode
- DocumentNode
- ElementNode
- CommentNode
-)
-
-// A Node consists of a NodeType and some Data (tag name for element nodes,
-// content for text) and are part of a tree of Nodes. Element nodes may also
-// contain a slice of Attributes. Data is unescaped, so that it looks like
-// "a<b" rather than "a&lt;b".
-type Node struct {
- Parent *Node
- Child []*Node
- Type NodeType
- Data string
- Attr []Attribute
-}
-
-// A parser implements the HTML5 parsing algorithm:
-// http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#tree-construction
-type parser struct {
- // tokenizer provides the tokens for the parser.
- tokenizer *Tokenizer
- // tok is the most recently read token.
- tok Token
- // Self-closing tags like <hr/> are re-interpreted as a two-token sequence:
- // <hr> followed by </hr>. hasSelfClosingToken is true if we have just read
- // the synthetic start tag and the next one due is the matching end tag.
- hasSelfClosingToken bool
- // doc is the document root element.
- doc *Node
- // The stack of open elements (section 10.2.3.2).
- stack []*Node
- // Element pointers (section 10.2.3.4).
- head, form *Node
- // Other parsing state flags (section 10.2.3.5).
- scripting, framesetOK bool
-}
-
-// push pushes onto the stack of open elements.
-func (p *parser) push(n *Node) {
- p.stack = append(p.stack, n)
-}
-
-// top returns the top of the stack of open elements.
-// This is also known as the current node.
-func (p *parser) top() *Node {
- if n := len(p.stack); n > 0 {
- return p.stack[n-1]
- }
- return p.doc
-}
-
-// pop pops the top of the stack of open elements.
-// It will panic if the stack is empty.
-func (p *parser) pop() *Node {
- n := len(p.stack)
- ret := p.stack[n-1]
- p.stack = p.stack[:n-1]
- return ret
-}
-
-// stopTags for use in popUntil. These come from section 10.2.3.2.
-var (
- defaultScopeStopTags = []string{"applet", "caption", "html", "table", "td", "th", "marquee", "object"}
- listItemScopeStopTags = []string{"applet", "caption", "html", "table", "td", "th", "marquee", "object", "ol", "ul"}
- buttonScopeStopTags = []string{"applet", "caption", "html", "table", "td", "th", "marquee", "object", "button"}
- tableScopeStopTags = []string{"html", "table"}
-)
-
-// popUntil pops the stack of open elements at the highest element whose tag
-// is in matchTags, provided there is no higher element in stopTags. It returns
-// whether or not there was such an element. If there was not, popUntil leaves
-// the stack unchanged.
-//
-// For example, if the stack was:
-// ["html", "body", "font", "table", "b", "i", "u"]
-// then popUntil([]string{"html, "table"}, "font") would return false, but
-// popUntil([]string{"html, "table"}, "i") would return true and the resultant
-// stack would be:
-// ["html", "body", "font", "table", "b"]
-//
-// If an element's tag is in both stopTags and matchTags, then the stack will
-// be popped and the function returns true (provided, of course, there was no
-// higher element in the stack that was also in stopTags). For example,
-// popUntil([]string{"html, "table"}, "table") would return true and leave:
-// ["html", "body", "font"]
-func (p *parser) popUntil(stopTags []string, matchTags ...string) bool {
- for i := len(p.stack) - 1; i >= 0; i-- {
- tag := p.stack[i].Data
- for _, t := range matchTags {
- if t == tag {
- p.stack = p.stack[:i]
- return true
- }
- }
- for _, t := range stopTags {
- if t == tag {
- return false
- }
- }
- }
- return false
-}
-
-// addChild adds a child node n to the top element, and pushes n if it is an
-// element node (text nodes are not part of the stack of open elements).
-func (p *parser) addChild(n *Node) {
- m := p.top()
- m.Child = append(m.Child, n)
- if n.Type == ElementNode {
- p.push(n)
- }
-}
-
-// addText calls addChild with a text node.
-func (p *parser) addText(text string) {
- // TODO: merge s with previous text, if the preceding node is a text node.
- // TODO: distinguish whitespace text from others.
- p.addChild(&Node{
- Type: TextNode,
- Data: text,
- })
-}
-
-// addElement calls addChild with an element node.
-func (p *parser) addElement(tag string, attr []Attribute) {
- p.addChild(&Node{
- Type: ElementNode,
- Data: tag,
- Attr: attr,
- })
-}
-
-// Section 10.2.3.3.
-func (p *parser) addFormattingElement(tag string, attr []Attribute) {
- p.addElement(tag, attr)
- // TODO.
-}
-
-// Section 10.2.3.3.
-func (p *parser) reconstructActiveFormattingElements() {
- // TODO.
-}
-
-// read reads the next token. This is usually from the tokenizer, but it may
-// be the synthesized end tag implied by a self-closing tag.
-func (p *parser) read() os.Error {
- if p.hasSelfClosingToken {
- p.hasSelfClosingToken = false
- p.tok.Type = EndTagToken
- p.tok.Attr = nil
- return nil
- }
- p.tokenizer.Next()
- p.tok = p.tokenizer.Token()
- switch p.tok.Type {
- case ErrorToken:
- return p.tokenizer.Error()
- case SelfClosingTagToken:
- p.hasSelfClosingToken = true
- p.tok.Type = StartTagToken
- }
- return nil
-}
-
-// Section 10.2.4.
-func (p *parser) acknowledgeSelfClosingTag() {
- p.hasSelfClosingToken = false
-}
-
-// An insertion mode (section 10.2.3.1) is the state transition function from
-// a particular state in the HTML5 parser's state machine. It updates the
-// parser's fields depending on parser.token (where ErrorToken means EOF). In
-// addition to returning the next insertionMode state, it also returns whether
-// the token was consumed.
-type insertionMode func(*parser) (insertionMode, bool)
-
-// useTheRulesFor runs the delegate insertionMode over p, returning the actual
-// insertionMode unless the delegate caused a state transition.
-// Section 10.2.3.1, "using the rules for".
-func useTheRulesFor(p *parser, actual, delegate insertionMode) (insertionMode, bool) {
- im, consumed := delegate(p)
- if im != delegate {
- return im, consumed
- }
- return actual, consumed
-}
-
-// Section 10.2.5.4.
-func initialIM(p *parser) (insertionMode, bool) {
- // TODO: check p.tok for DOCTYPE.
- return beforeHTMLIM, false
-}
-
-// Section 10.2.5.5.
-func beforeHTMLIM(p *parser) (insertionMode, bool) {
- var (
- add bool
- attr []Attribute
- implied bool
- )
- switch p.tok.Type {
- case ErrorToken:
- implied = true
- case TextToken:
- // TODO: distinguish whitespace text from others.
- implied = true
- case StartTagToken:
- if p.tok.Data == "html" {
- add = true
- attr = p.tok.Attr
- } else {
- implied = true
- }
- case EndTagToken:
- switch p.tok.Data {
- case "head", "body", "html", "br":
- implied = true
- default:
- // Ignore the token.
- }
- }
- if add || implied {
- p.addElement("html", attr)
- }
- return beforeHeadIM, !implied
-}
-
-// Section 10.2.5.6.
-func beforeHeadIM(p *parser) (insertionMode, bool) {
- var (
- add bool
- attr []Attribute
- implied bool
- )
- switch p.tok.Type {
- case ErrorToken:
- implied = true
- case TextToken:
- // TODO: distinguish whitespace text from others.
- implied = true
- case StartTagToken:
- switch p.tok.Data {
- case "head":
- add = true
- attr = p.tok.Attr
- case "html":
- return useTheRulesFor(p, beforeHeadIM, inBodyIM)
- default:
- implied = true
- }
- case EndTagToken:
- switch p.tok.Data {
- case "head", "body", "html", "br":
- implied = true
- default:
- // Ignore the token.
- }
- }
- if add || implied {
- p.addElement("head", attr)
- }
- return inHeadIM, !implied
-}
-
-// Section 10.2.5.7.
-func inHeadIM(p *parser) (insertionMode, bool) {
- var (
- pop bool
- implied bool
- )
- switch p.tok.Type {
- case ErrorToken, TextToken:
- implied = true
- case StartTagToken:
- switch p.tok.Data {
- case "meta":
- // TODO.
- case "script":
- // TODO.
- default:
- implied = true
- }
- case EndTagToken:
- if p.tok.Data == "head" {
- pop = true
- }
- // TODO.
- }
- if pop || implied {
- n := p.pop()
- if n.Data != "head" {
- panic("html: bad parser state")
- }
- return afterHeadIM, !implied
- }
- return inHeadIM, !implied
-}
-
-// Section 10.2.5.9.
-func afterHeadIM(p *parser) (insertionMode, bool) {
- var (
- add bool
- attr []Attribute
- framesetOK bool
- implied bool
- )
- switch p.tok.Type {
- case ErrorToken, TextToken:
- implied = true
- framesetOK = true
- case StartTagToken:
- switch p.tok.Data {
- case "html":
- // TODO.
- case "body":
- add = true
- attr = p.tok.Attr
- framesetOK = false
- case "frameset":
- // TODO.
- case "base", "basefont", "bgsound", "link", "meta", "noframes", "script", "style", "title":
- // TODO.
- case "head":
- // TODO.
- default:
- implied = true
- framesetOK = true
- }
- case EndTagToken:
- // TODO.
- }
- if add || implied {
- p.addElement("body", attr)
- p.framesetOK = framesetOK
- }
- return inBodyIM, !implied
-}
-
-// Section 10.2.5.10.
-func inBodyIM(p *parser) (insertionMode, bool) {
- var endP bool
- switch p.tok.Type {
- case TextToken:
- p.addText(p.tok.Data)
- p.framesetOK = false
- case StartTagToken:
- switch p.tok.Data {
- case "address", "article", "aside", "blockquote", "center", "details", "dir", "div", "dl", "fieldset", "figcaption", "figure", "footer", "header", "hgroup", "menu", "nav", "ol", "p", "section", "summary", "ul":
- // TODO: Do the proper "does the stack of open elements has a p element in button scope" algorithm in section 10.2.3.2.
- n := p.top()
- if n.Type == ElementNode && n.Data == "p" {
- endP = true
- } else {
- p.addElement(p.tok.Data, p.tok.Attr)
- }
- case "h1", "h2", "h3", "h4", "h5", "h6":
- // TODO: auto-insert </p> if necessary.
- switch n := p.top(); n.Data {
- case "h1", "h2", "h3", "h4", "h5", "h6":
- p.pop()
- }
- p.addElement(p.tok.Data, p.tok.Attr)
- case "b", "big", "code", "em", "font", "i", "s", "small", "strike", "strong", "tt", "u":
- p.reconstructActiveFormattingElements()
- p.addFormattingElement(p.tok.Data, p.tok.Attr)
- case "area", "br", "embed", "img", "input", "keygen", "wbr":
- p.reconstructActiveFormattingElements()
- p.addElement(p.tok.Data, p.tok.Attr)
- p.pop()
- p.acknowledgeSelfClosingTag()
- p.framesetOK = false
- case "table":
- // TODO: auto-insert </p> if necessary, depending on quirks mode.
- p.addElement(p.tok.Data, p.tok.Attr)
- p.framesetOK = false
- return inTableIM, true
- case "hr":
- // TODO: auto-insert </p> if necessary.
- p.addElement(p.tok.Data, p.tok.Attr)
- p.pop()
- p.acknowledgeSelfClosingTag()
- p.framesetOK = false
- default:
- // TODO.
- p.addElement(p.tok.Data, p.tok.Attr)
- }
- case EndTagToken:
- switch p.tok.Data {
- case "body":
- // TODO: autoclose the stack of open elements.
- return afterBodyIM, true
- case "a", "b", "big", "code", "em", "font", "i", "nobr", "s", "small", "strike", "strong", "tt", "u":
- // TODO: implement the "adoption agency" algorithm:
- // http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#adoptionAgency
- if p.tok.Data == p.top().Data {
- p.pop()
- }
- default:
- // TODO: any other end tag
- if p.tok.Data == p.top().Data {
- p.pop()
- }
- }
- }
- if endP {
- // TODO: do the proper algorithm.
- n := p.pop()
- if n.Type != ElementNode || n.Data != "p" {
- panic("unreachable")
- }
- }
- return inBodyIM, !endP
-}
-
-// Section 10.2.5.12.
-func inTableIM(p *parser) (insertionMode, bool) {
- var (
- add bool
- data string
- attr []Attribute
- consumed bool
- )
- switch p.tok.Type {
- case ErrorToken:
- // Stop parsing.
- return nil, true
- case TextToken:
- // TODO.
- case StartTagToken:
- switch p.tok.Data {
- case "tbody", "tfoot", "thead":
- add = true
- data = p.tok.Data
- attr = p.tok.Attr
- consumed = true
- case "td", "th", "tr":
- add = true
- data = "tbody"
- default:
- // TODO.
- }
- case EndTagToken:
- switch p.tok.Data {
- case "table":
- if p.popUntil(tableScopeStopTags, "table") {
- // TODO: "reset the insertion mode appropriately" as per 10.2.3.1.
- return inBodyIM, false
- }
- // Ignore the token.
- return inTableIM, true
- case "body", "caption", "col", "colgroup", "html", "tbody", "td", "tfoot", "th", "thead", "tr":
- // Ignore the token.
- return inTableIM, true
- }
- }
- if add {
- // TODO: clear the stack back to a table context.
- p.addElement(data, attr)
- return inTableBodyIM, consumed
- }
- // TODO: return useTheRulesFor(inTableIM, inBodyIM, p) unless etc. etc. foster parenting.
- return inTableIM, true
-}
-
-// Section 10.2.5.16.
-func inTableBodyIM(p *parser) (insertionMode, bool) {
- var (
- add bool
- data string
- attr []Attribute
- consumed bool
- )
- switch p.tok.Type {
- case ErrorToken:
- // TODO.
- case TextToken:
- // TODO.
- case StartTagToken:
- switch p.tok.Data {
- case "tr":
- add = true
- data = p.tok.Data
- attr = p.tok.Attr
- consumed = true
- case "td", "th":
- add = true
- data = "tr"
- consumed = false
- default:
- // TODO.
- }
- case EndTagToken:
- switch p.tok.Data {
- case "table":
- if p.popUntil(tableScopeStopTags, "tbody", "thead", "tfoot") {
- return inTableIM, false
- }
- // Ignore the token.
- return inTableBodyIM, true
- case "body", "caption", "col", "colgroup", "html", "td", "th", "tr":
- // Ignore the token.
- return inTableBodyIM, true
- }
- }
- if add {
- // TODO: clear the stack back to a table body context.
- p.addElement(data, attr)
- return inRowIM, consumed
- }
- return useTheRulesFor(p, inTableBodyIM, inTableIM)
-}
-
-// Section 10.2.5.17.
-func inRowIM(p *parser) (insertionMode, bool) {
- switch p.tok.Type {
- case ErrorToken:
- // TODO.
- case TextToken:
- // TODO.
- case StartTagToken:
- switch p.tok.Data {
- case "td", "th":
- // TODO: clear the stack back to a table row context.
- p.addElement(p.tok.Data, p.tok.Attr)
- // TODO: insert a marker at the end of the list of active formatting elements.
- return inCellIM, true
- default:
- // TODO.
- }
- case EndTagToken:
- switch p.tok.Data {
- case "tr":
- // TODO.
- case "table":
- if p.popUntil(tableScopeStopTags, "tr") {
- return inTableBodyIM, false
- }
- // Ignore the token.
- return inRowIM, true
- case "tbody", "tfoot", "thead":
- // TODO.
- case "body", "caption", "col", "colgroup", "html", "td", "th":
- // Ignore the token.
- return inRowIM, true
- default:
- // TODO.
- }
- }
- return useTheRulesFor(p, inRowIM, inTableIM)
-}
-
-// Section 10.2.5.18.
-func inCellIM(p *parser) (insertionMode, bool) {
- var (
- closeTheCellAndReprocess bool
- )
- switch p.tok.Type {
- case StartTagToken:
- switch p.tok.Data {
- case "caption", "col", "colgroup", "tbody", "td", "tfoot", "th", "thead", "tr":
- // TODO: check for "td" or "th" in table scope.
- closeTheCellAndReprocess = true
- }
- case EndTagToken:
- switch p.tok.Data {
- case "td", "th":
- // TODO.
- case "body", "caption", "col", "colgroup", "html":
- // TODO.
- case "table", "tbody", "tfoot", "thead", "tr":
- // TODO: check for matching element in table scope.
- closeTheCellAndReprocess = true
- }
- }
- if closeTheCellAndReprocess {
- if p.popUntil(tableScopeStopTags, "td") || p.popUntil(tableScopeStopTags, "th") {
- // TODO: clear the list of active formatting elements up to the last marker.
- return inRowIM, false
- }
- }
- return useTheRulesFor(p, inCellIM, inBodyIM)
-}
-
-// Section 10.2.5.22.
-func afterBodyIM(p *parser) (insertionMode, bool) {
- switch p.tok.Type {
- case ErrorToken:
- // TODO.
- case TextToken:
- // TODO.
- case StartTagToken:
- // TODO.
- case EndTagToken:
- switch p.tok.Data {
- case "html":
- // TODO: autoclose the stack of open elements.
- return afterAfterBodyIM, true
- default:
- // TODO.
- }
- }
- return afterBodyIM, true
-}
-
-// Section 10.2.5.25.
-func afterAfterBodyIM(p *parser) (insertionMode, bool) {
- switch p.tok.Type {
- case ErrorToken:
- // Stop parsing.
- return nil, true
- case TextToken:
- // TODO.
- case StartTagToken:
- if p.tok.Data == "html" {
- return useTheRulesFor(p, afterAfterBodyIM, inBodyIM)
- }
- }
- return inBodyIM, false
-}
-
-// Parse returns the parse tree for the HTML from the given Reader.
-// The input is assumed to be UTF-8 encoded.
-func Parse(r io.Reader) (*Node, os.Error) {
- p := &parser{
- tokenizer: NewTokenizer(r),
- doc: &Node{
- Type: DocumentNode,
- },
- scripting: true,
- framesetOK: true,
- }
- // Iterate until EOF. Any other error will cause an early return.
- im, consumed := initialIM, true
- for {
- if consumed {
- if err := p.read(); err != nil {
- if err == os.EOF {
- break
- }
- return nil, err
- }
- }
- im, consumed = im(p)
- }
- // Loop until the final token (the ErrorToken signifying EOF) is consumed.
- for {
- if im, consumed = im(p); consumed {
- break
- }
- }
- return p.doc, nil
-}
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