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Diffstat (limited to 'vendor/golang.org/x/net/html/node.go')
-rw-r--r-- | vendor/golang.org/x/net/html/node.go | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/html/node.go b/vendor/golang.org/x/net/html/node.go new file mode 100644 index 00000000..633ee15d --- /dev/null +++ b/vendor/golang.org/x/net/html/node.go @@ -0,0 +1,220 @@ +// Copyright 2011 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 ( + "golang.org/x/net/html/atom" +) + +// A NodeType is the type of a Node. +type NodeType uint32 + +const ( + ErrorNode NodeType = iota + TextNode + DocumentNode + ElementNode + CommentNode + DoctypeNode + scopeMarkerNode +) + +// Section 12.2.4.3 says "The markers are inserted when entering applet, +// object, marquee, template, td, th, and caption elements, and are used +// to prevent formatting from "leaking" into applet, object, marquee, +// template, td, th, and caption elements". +var scopeMarker = Node{Type: scopeMarkerNode} + +// 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 +// have a Namespace and contain a slice of Attributes. Data is unescaped, so +// that it looks like "a<b" rather than "a<b". For element nodes, DataAtom +// is the atom for Data, or zero if Data is not a known tag name. +// +// An empty Namespace implies a "http://www.w3.org/1999/xhtml" namespace. +// Similarly, "math" is short for "http://www.w3.org/1998/Math/MathML", and +// "svg" is short for "http://www.w3.org/2000/svg". +type Node struct { + Parent, FirstChild, LastChild, PrevSibling, NextSibling *Node + + Type NodeType + DataAtom atom.Atom + Data string + Namespace string + Attr []Attribute +} + +// InsertBefore inserts newChild as a child of n, immediately before oldChild +// in the sequence of n's children. oldChild may be nil, in which case newChild +// is appended to the end of n's children. +// +// It will panic if newChild already has a parent or siblings. +func (n *Node) InsertBefore(newChild, oldChild *Node) { + if newChild.Parent != nil || newChild.PrevSibling != nil || newChild.NextSibling != nil { + panic("html: InsertBefore called for an attached child Node") + } + var prev, next *Node + if oldChild != nil { + prev, next = oldChild.PrevSibling, oldChild + } else { + prev = n.LastChild + } + if prev != nil { + prev.NextSibling = newChild + } else { + n.FirstChild = newChild + } + if next != nil { + next.PrevSibling = newChild + } else { + n.LastChild = newChild + } + newChild.Parent = n + newChild.PrevSibling = prev + newChild.NextSibling = next +} + +// AppendChild adds a node c as a child of n. +// +// It will panic if c already has a parent or siblings. +func (n *Node) AppendChild(c *Node) { + if c.Parent != nil || c.PrevSibling != nil || c.NextSibling != nil { + panic("html: AppendChild called for an attached child Node") + } + last := n.LastChild + if last != nil { + last.NextSibling = c + } else { + n.FirstChild = c + } + n.LastChild = c + c.Parent = n + c.PrevSibling = last +} + +// RemoveChild removes a node c that is a child of n. Afterwards, c will have +// no parent and no siblings. +// +// It will panic if c's parent is not n. +func (n *Node) RemoveChild(c *Node) { + if c.Parent != n { + panic("html: RemoveChild called for a non-child Node") + } + if n.FirstChild == c { + n.FirstChild = c.NextSibling + } + if c.NextSibling != nil { + c.NextSibling.PrevSibling = c.PrevSibling + } + if n.LastChild == c { + n.LastChild = c.PrevSibling + } + if c.PrevSibling != nil { + c.PrevSibling.NextSibling = c.NextSibling + } + c.Parent = nil + c.PrevSibling = nil + c.NextSibling = nil +} + +// reparentChildren reparents all of src's child nodes to dst. +func reparentChildren(dst, src *Node) { + for { + child := src.FirstChild + if child == nil { + break + } + src.RemoveChild(child) + dst.AppendChild(child) + } +} + +// clone returns a new node with the same type, data and attributes. +// The clone has no parent, no siblings and no children. +func (n *Node) clone() *Node { + m := &Node{ + Type: n.Type, + DataAtom: n.DataAtom, + Data: n.Data, + Attr: make([]Attribute, len(n.Attr)), + } + copy(m.Attr, n.Attr) + return m +} + +// nodeStack is a stack of nodes. +type nodeStack []*Node + +// pop pops the stack. It will panic if s is empty. +func (s *nodeStack) pop() *Node { + i := len(*s) + n := (*s)[i-1] + *s = (*s)[:i-1] + return n +} + +// top returns the most recently pushed node, or nil if s is empty. +func (s *nodeStack) top() *Node { + if i := len(*s); i > 0 { + return (*s)[i-1] + } + return nil +} + +// index returns the index of the top-most occurrence of n in the stack, or -1 +// if n is not present. +func (s *nodeStack) index(n *Node) int { + for i := len(*s) - 1; i >= 0; i-- { + if (*s)[i] == n { + return i + } + } + return -1 +} + +// contains returns whether a is within s. +func (s *nodeStack) contains(a atom.Atom) bool { + for _, n := range *s { + if n.DataAtom == a && n.Namespace == "" { + return true + } + } + return false +} + +// insert inserts a node at the given index. +func (s *nodeStack) insert(i int, n *Node) { + (*s) = append(*s, nil) + copy((*s)[i+1:], (*s)[i:]) + (*s)[i] = n +} + +// remove removes a node from the stack. It is a no-op if n is not present. +func (s *nodeStack) remove(n *Node) { + i := s.index(n) + if i == -1 { + return + } + copy((*s)[i:], (*s)[i+1:]) + j := len(*s) - 1 + (*s)[j] = nil + *s = (*s)[:j] +} + +type insertionModeStack []insertionMode + +func (s *insertionModeStack) pop() (im insertionMode) { + i := len(*s) + im = (*s)[i-1] + *s = (*s)[:i-1] + return im +} + +func (s *insertionModeStack) top() insertionMode { + if i := len(*s); i > 0 { + return (*s)[i-1] + } + return nil +} |