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Diffstat (limited to 'vendor/golang.org/x/net/html/doc.go')
-rw-r--r-- | vendor/golang.org/x/net/html/doc.go | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/vendor/golang.org/x/net/html/doc.go b/vendor/golang.org/x/net/html/doc.go deleted file mode 100644 index 94f49687..00000000 --- a/vendor/golang.org/x/net/html/doc.go +++ /dev/null @@ -1,106 +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 implements an HTML5-compliant tokenizer and parser. - -Tokenization is done by creating a Tokenizer for an io.Reader r. It is the -caller's responsibility to ensure that r provides UTF-8 encoded HTML. - - z := html.NewTokenizer(r) - -Given a Tokenizer z, the HTML is tokenized by repeatedly calling z.Next(), -which parses the next token and returns its type, or an error: - - for { - tt := z.Next() - if tt == html.ErrorToken { - // ... - return ... - } - // Process the current token. - } - -There are two APIs for retrieving the current token. The high-level API is to -call Token; the low-level API is to call Text or TagName / TagAttr. Both APIs -allow optionally calling Raw after Next but before Token, Text, TagName, or -TagAttr. In EBNF notation, the valid call sequence per token is: - - Next {Raw} [ Token | Text | TagName {TagAttr} ] - -Token returns an independent data structure that completely describes a token. -Entities (such as "<") are unescaped, tag names and attribute keys are -lower-cased, and attributes are collected into a []Attribute. For example: - - for { - if z.Next() == html.ErrorToken { - // Returning io.EOF indicates success. - return z.Err() - } - emitToken(z.Token()) - } - -The low-level API performs fewer allocations and copies, but the contents of -the []byte values returned by Text, TagName and TagAttr may change on the next -call to Next. For example, to extract an HTML page's anchor text: - - depth := 0 - for { - tt := z.Next() - switch tt { - case ErrorToken: - return z.Err() - case TextToken: - if depth > 0 { - // emitBytes should copy the []byte it receives, - // if it doesn't process it immediately. - emitBytes(z.Text()) - } - case StartTagToken, EndTagToken: - tn, _ := z.TagName() - if len(tn) == 1 && tn[0] == 'a' { - if tt == StartTagToken { - depth++ - } else { - depth-- - } - } - } - } - -Parsing is done by calling Parse with an io.Reader, which returns the root of -the parse tree (the document element) as a *Node. It is the caller's -responsibility to ensure that the Reader provides UTF-8 encoded HTML. For -example, to process each anchor node in depth-first order: - - doc, err := html.Parse(r) - if err != nil { - // ... - } - var f func(*html.Node) - f = func(n *html.Node) { - if n.Type == html.ElementNode && n.Data == "a" { - // Do something with n... - } - for c := n.FirstChild; c != nil; c = c.NextSibling { - f(c) - } - } - f(doc) - -The relevant specifications include: -https://html.spec.whatwg.org/multipage/syntax.html and -https://html.spec.whatwg.org/multipage/syntax.html#tokenization -*/ -package html // import "golang.org/x/net/html" - -// The tokenization algorithm implemented by this package is not a line-by-line -// transliteration of the relatively verbose state-machine in the WHATWG -// specification. A more direct approach is used instead, where the program -// counter implies the state, such as whether it is tokenizing a tag or a text -// node. Specification compliance is verified by checking expected and actual -// outputs over a test suite rather than aiming for algorithmic fidelity. - -// TODO(nigeltao): Does a DOM API belong in this package or a separate one? -// TODO(nigeltao): How does parsing interact with a JavaScript engine? |