[chore/bugfix] Switch markdown from blackfriday to goldmark (#1267)

Co-authored-by: Autumn! <autumnull@posteo.net>

vendor/github.com/yuin/goldmark/ast/ast.go

@@ -0,0 +1,508 @@
+// Package ast defines AST nodes that represent markdown elements.
+package ast
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	textm "github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+// A NodeType indicates what type a node belongs to.
+type NodeType int
+
+const (
+	// TypeBlock indicates that a node is kind of block nodes.
+	TypeBlock NodeType = iota + 1
+	// TypeInline indicates that a node is kind of inline nodes.
+	TypeInline
+	// TypeDocument indicates that a node is kind of document nodes.
+	TypeDocument
+)
+
+// NodeKind indicates more specific type than NodeType.
+type NodeKind int
+
+func (k NodeKind) String() string {
+	return kindNames[k]
+}
+
+var kindMax NodeKind
+var kindNames = []string{""}
+
+// NewNodeKind returns a new Kind value.
+func NewNodeKind(name string) NodeKind {
+	kindMax++
+	kindNames = append(kindNames, name)
+	return kindMax
+}
+
+// An Attribute is an attribute of the Node
+type Attribute struct {
+	Name  []byte
+	Value interface{}
+}
+
+// A Node interface defines basic AST node functionalities.
+type Node interface {
+	// Type returns a type of this node.
+	Type() NodeType
+
+	// Kind returns a kind of this node.
+	Kind() NodeKind
+
+	// NextSibling returns a next sibling node of this node.
+	NextSibling() Node
+
+	// PreviousSibling returns a previous sibling node of this node.
+	PreviousSibling() Node
+
+	// Parent returns a parent node of this node.
+	Parent() Node
+
+	// SetParent sets a parent node to this node.
+	SetParent(Node)
+
+	// SetPreviousSibling sets a previous sibling node to this node.
+	SetPreviousSibling(Node)
+
+	// SetNextSibling sets a next sibling node to this node.
+	SetNextSibling(Node)
+
+	// HasChildren returns true if this node has any children, otherwise false.
+	HasChildren() bool
+
+	// ChildCount returns a total number of children.
+	ChildCount() int
+
+	// FirstChild returns a first child of this node.
+	FirstChild() Node
+
+	// LastChild returns a last child of this node.
+	LastChild() Node
+
+	// AppendChild append a node child to the tail of the children.
+	AppendChild(self, child Node)
+
+	// RemoveChild removes a node child from this node.
+	// If a node child is not children of this node, RemoveChild nothing to do.
+	RemoveChild(self, child Node)
+
+	// RemoveChildren removes all children from this node.
+	RemoveChildren(self Node)
+
+	// SortChildren sorts childrens by comparator.
+	SortChildren(comparator func(n1, n2 Node) int)
+
+	// ReplaceChild replace a node v1 with a node insertee.
+	// If v1 is not children of this node, ReplaceChild append a insetee to the
+	// tail of the children.
+	ReplaceChild(self, v1, insertee Node)
+
+	// InsertBefore inserts a node insertee before a node v1.
+	// If v1 is not children of this node, InsertBefore append a insetee to the
+	// tail of the children.
+	InsertBefore(self, v1, insertee Node)
+
+	// InsertAfterinserts a node insertee after a node v1.
+	// If v1 is not children of this node, InsertBefore append a insetee to the
+	// tail of the children.
+	InsertAfter(self, v1, insertee Node)
+
+	// OwnerDocument returns this node's owner document.
+	// If this node is not a child of the Document node, OwnerDocument
+	// returns nil.
+	OwnerDocument() *Document
+
+	// Dump dumps an AST tree structure to stdout.
+	// This function completely aimed for debugging.
+	// level is a indent level. Implementer should indent informations with
+	// 2 * level spaces.
+	Dump(source []byte, level int)
+
+	// Text returns text values of this node.
+	Text(source []byte) []byte
+
+	// HasBlankPreviousLines returns true if the row before this node is blank,
+	// otherwise false.
+	// This method is valid only for block nodes.
+	HasBlankPreviousLines() bool
+
+	// SetBlankPreviousLines sets whether the row before this node is blank.
+	// This method is valid only for block nodes.
+	SetBlankPreviousLines(v bool)
+
+	// Lines returns text segments that hold positions in a source.
+	// This method is valid only for block nodes.
+	Lines() *textm.Segments
+
+	// SetLines sets text segments that hold positions in a source.
+	// This method is valid only for block nodes.
+	SetLines(*textm.Segments)
+
+	// IsRaw returns true if contents should be rendered as 'raw' contents.
+	IsRaw() bool
+
+	// SetAttribute sets the given value to the attributes.
+	SetAttribute(name []byte, value interface{})
+
+	// SetAttributeString sets the given value to the attributes.
+	SetAttributeString(name string, value interface{})
+
+	// Attribute returns a (attribute value, true) if an attribute
+	// associated with the given name is found, otherwise
+	// (nil, false)
+	Attribute(name []byte) (interface{}, bool)
+
+	// AttributeString returns a (attribute value, true) if an attribute
+	// associated with the given name is found, otherwise
+	// (nil, false)
+	AttributeString(name string) (interface{}, bool)
+
+	// Attributes returns a list of attributes.
+	// This may be a nil if there are no attributes.
+	Attributes() []Attribute
+
+	// RemoveAttributes removes all attributes from this node.
+	RemoveAttributes()
+}
+
+// A BaseNode struct implements the Node interface partialliy.
+type BaseNode struct {
+	firstChild Node
+	lastChild  Node
+	parent     Node
+	next       Node
+	prev       Node
+	childCount int
+	attributes []Attribute
+}
+
+func ensureIsolated(v Node) {
+	if p := v.Parent(); p != nil {
+		p.RemoveChild(p, v)
+	}
+}
+
+// HasChildren implements Node.HasChildren .
+func (n *BaseNode) HasChildren() bool {
+	return n.firstChild != nil
+}
+
+// SetPreviousSibling implements Node.SetPreviousSibling .
+func (n *BaseNode) SetPreviousSibling(v Node) {
+	n.prev = v
+}
+
+// SetNextSibling implements Node.SetNextSibling .
+func (n *BaseNode) SetNextSibling(v Node) {
+	n.next = v
+}
+
+// PreviousSibling implements Node.PreviousSibling .
+func (n *BaseNode) PreviousSibling() Node {
+	return n.prev
+}
+
+// NextSibling implements Node.NextSibling .
+func (n *BaseNode) NextSibling() Node {
+	return n.next
+}
+
+// RemoveChild implements Node.RemoveChild .
+func (n *BaseNode) RemoveChild(self, v Node) {
+	if v.Parent() != self {
+		return
+	}
+	n.childCount--
+	prev := v.PreviousSibling()
+	next := v.NextSibling()
+	if prev != nil {
+		prev.SetNextSibling(next)
+	} else {
+		n.firstChild = next
+	}
+	if next != nil {
+		next.SetPreviousSibling(prev)
+	} else {
+		n.lastChild = prev
+	}
+	v.SetParent(nil)
+	v.SetPreviousSibling(nil)
+	v.SetNextSibling(nil)
+}
+
+// RemoveChildren implements Node.RemoveChildren .
+func (n *BaseNode) RemoveChildren(self Node) {
+	for c := n.firstChild; c != nil; {
+		c.SetParent(nil)
+		c.SetPreviousSibling(nil)
+		next := c.NextSibling()
+		c.SetNextSibling(nil)
+		c = next
+	}
+	n.firstChild = nil
+	n.lastChild = nil
+	n.childCount = 0
+}
+
+// SortChildren implements Node.SortChildren
+func (n *BaseNode) SortChildren(comparator func(n1, n2 Node) int) {
+	var sorted Node
+	current := n.firstChild
+	for current != nil {
+		next := current.NextSibling()
+		if sorted == nil || comparator(sorted, current) >= 0 {
+			current.SetNextSibling(sorted)
+			if sorted != nil {
+				sorted.SetPreviousSibling(current)
+			}
+			sorted = current
+			sorted.SetPreviousSibling(nil)
+		} else {
+			c := sorted
+			for c.NextSibling() != nil && comparator(c.NextSibling(), current) < 0 {
+				c = c.NextSibling()
+			}
+			current.SetNextSibling(c.NextSibling())
+			current.SetPreviousSibling(c)
+			if c.NextSibling() != nil {
+				c.NextSibling().SetPreviousSibling(current)
+			}
+			c.SetNextSibling(current)
+		}
+		current = next
+	}
+	n.firstChild = sorted
+	for c := n.firstChild; c != nil; c = c.NextSibling() {
+		n.lastChild = c
+	}
+}
+
+// FirstChild implements Node.FirstChild .
+func (n *BaseNode) FirstChild() Node {
+	return n.firstChild
+}
+
+// LastChild implements Node.LastChild .
+func (n *BaseNode) LastChild() Node {
+	return n.lastChild
+}
+
+// ChildCount implements Node.ChildCount .
+func (n *BaseNode) ChildCount() int {
+	return n.childCount
+}
+
+// Parent implements Node.Parent .
+func (n *BaseNode) Parent() Node {
+	return n.parent
+}
+
+// SetParent implements Node.SetParent .
+func (n *BaseNode) SetParent(v Node) {
+	n.parent = v
+}
+
+// AppendChild implements Node.AppendChild .
+func (n *BaseNode) AppendChild(self, v Node) {
+	ensureIsolated(v)
+	if n.firstChild == nil {
+		n.firstChild = v
+		v.SetNextSibling(nil)
+		v.SetPreviousSibling(nil)
+	} else {
+		last := n.lastChild
+		last.SetNextSibling(v)
+		v.SetPreviousSibling(last)
+	}
+	v.SetParent(self)
+	n.lastChild = v
+	n.childCount++
+}
+
+// ReplaceChild implements Node.ReplaceChild .
+func (n *BaseNode) ReplaceChild(self, v1, insertee Node) {
+	n.InsertBefore(self, v1, insertee)
+	n.RemoveChild(self, v1)
+}
+
+// InsertAfter implements Node.InsertAfter .
+func (n *BaseNode) InsertAfter(self, v1, insertee Node) {
+	n.InsertBefore(self, v1.NextSibling(), insertee)
+}
+
+// InsertBefore implements Node.InsertBefore .
+func (n *BaseNode) InsertBefore(self, v1, insertee Node) {
+	n.childCount++
+	if v1 == nil {
+		n.AppendChild(self, insertee)
+		return
+	}
+	ensureIsolated(insertee)
+	if v1.Parent() == self {
+		c := v1
+		prev := c.PreviousSibling()
+		if prev != nil {
+			prev.SetNextSibling(insertee)
+			insertee.SetPreviousSibling(prev)
+		} else {
+			n.firstChild = insertee
+			insertee.SetPreviousSibling(nil)
+		}
+		insertee.SetNextSibling(c)
+		c.SetPreviousSibling(insertee)
+		insertee.SetParent(self)
+	}
+}
+
+// OwnerDocument implements Node.OwnerDocument
+func (n *BaseNode) OwnerDocument() *Document {
+	d := n.Parent()
+	for {
+		p := d.Parent()
+		if p == nil {
+			if v, ok := d.(*Document); ok {
+				return v
+			}
+			break
+		}
+		d = p
+	}
+	return nil
+}
+
+// Text implements Node.Text  .
+func (n *BaseNode) Text(source []byte) []byte {
+	var buf bytes.Buffer
+	for c := n.firstChild; c != nil; c = c.NextSibling() {
+		buf.Write(c.Text(source))
+	}
+	return buf.Bytes()
+}
+
+// SetAttribute implements Node.SetAttribute.
+func (n *BaseNode) SetAttribute(name []byte, value interface{}) {
+	if n.attributes == nil {
+		n.attributes = make([]Attribute, 0, 10)
+	} else {
+		for i, a := range n.attributes {
+			if bytes.Equal(a.Name, name) {
+				n.attributes[i].Name = name
+				n.attributes[i].Value = value
+				return
+			}
+		}
+	}
+	n.attributes = append(n.attributes, Attribute{name, value})
+}
+
+// SetAttributeString implements Node.SetAttributeString
+func (n *BaseNode) SetAttributeString(name string, value interface{}) {
+	n.SetAttribute(util.StringToReadOnlyBytes(name), value)
+}
+
+// Attribute implements Node.Attribute.
+func (n *BaseNode) Attribute(name []byte) (interface{}, bool) {
+	if n.attributes == nil {
+		return nil, false
+	}
+	for i, a := range n.attributes {
+		if bytes.Equal(a.Name, name) {
+			return n.attributes[i].Value, true
+		}
+	}
+	return nil, false
+}
+
+// AttributeString implements Node.AttributeString.
+func (n *BaseNode) AttributeString(s string) (interface{}, bool) {
+	return n.Attribute(util.StringToReadOnlyBytes(s))
+}
+
+// Attributes implements Node.Attributes
+func (n *BaseNode) Attributes() []Attribute {
+	return n.attributes
+}
+
+// RemoveAttributes implements Node.RemoveAttributes
+func (n *BaseNode) RemoveAttributes() {
+	n.attributes = nil
+}
+
+// DumpHelper is a helper function to implement Node.Dump.
+// kv is pairs of an attribute name and an attribute value.
+// cb is a function called after wrote a name and attributes.
+func DumpHelper(v Node, source []byte, level int, kv map[string]string, cb func(int)) {
+	name := v.Kind().String()
+	indent := strings.Repeat("    ", level)
+	fmt.Printf("%s%s {\n", indent, name)
+	indent2 := strings.Repeat("    ", level+1)
+	if v.Type() == TypeBlock {
+		fmt.Printf("%sRawText: \"", indent2)
+		for i := 0; i < v.Lines().Len(); i++ {
+			line := v.Lines().At(i)
+			fmt.Printf("%s", line.Value(source))
+		}
+		fmt.Printf("\"\n")
+		fmt.Printf("%sHasBlankPreviousLines: %v\n", indent2, v.HasBlankPreviousLines())
+	}
+	for name, value := range kv {
+		fmt.Printf("%s%s: %s\n", indent2, name, value)
+	}
+	if cb != nil {
+		cb(level + 1)
+	}
+	for c := v.FirstChild(); c != nil; c = c.NextSibling() {
+		c.Dump(source, level+1)
+	}
+	fmt.Printf("%s}\n", indent)
+}
+
+// WalkStatus represents a current status of the Walk function.
+type WalkStatus int
+
+const (
+	// WalkStop indicates no more walking needed.
+	WalkStop WalkStatus = iota + 1
+
+	// WalkSkipChildren indicates that Walk wont walk on children of current
+	// node.
+	WalkSkipChildren
+
+	// WalkContinue indicates that Walk can continue to walk.
+	WalkContinue
+)
+
+// Walker is a function that will be called when Walk find a
+// new node.
+// entering is set true before walks children, false after walked children.
+// If Walker returns error, Walk function immediately stop walking.
+type Walker func(n Node, entering bool) (WalkStatus, error)
+
+// Walk walks a AST tree by the depth first search algorithm.
+func Walk(n Node, walker Walker) error {
+	_, err := walkHelper(n, walker)
+	return err
+}
+
+func walkHelper(n Node, walker Walker) (WalkStatus, error) {
+	status, err := walker(n, true)
+	if err != nil || status == WalkStop {
+		return status, err
+	}
+	if status != WalkSkipChildren {
+		for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+			if st, err := walkHelper(c, walker); err != nil || st == WalkStop {
+				return WalkStop, err
+			}
+		}
+	}
+	status, err = walker(n, false)
+	if err != nil || status == WalkStop {
+		return WalkStop, err
+	}
+	return WalkContinue, nil
+}