vue3-core/packages/compiler-core/src/ast.ts

// Vue template is a platform-agnostic superset of HTML (syntax only).
// More namespaces like SVG and MathML are declared by platform specific
// compilers.
export type Namespace = number

export const enum Namespaces {
  HTML
}

export const enum NodeTypes {
  ROOT,
  ELEMENT,
  TEXT,
  COMMENT,
  EXPRESSION,
  ATTRIBUTE,
  DIRECTIVE,
  IF,
  IF_BRANCH,
  FOR
}

export const enum ElementTypes {
  ELEMENT,
  COMPONENT,
  SLOT,
  TEMPLATE
}

export interface Node {
  type: NodeTypes
  loc: SourceLocation
}

export type ParentNode = RootNode | ElementNode | IfBranchNode | ForNode
export type ChildNode =
  | ElementNode
  | ExpressionNode
  | TextNode
  | CommentNode
  | IfNode
  | ForNode

export interface RootNode extends Node {
  type: NodeTypes.ROOT
  children: ChildNode[]
}

export interface ElementNode extends Node {
  type: NodeTypes.ELEMENT
  ns: Namespace
  tag: string
  tagType: ElementTypes
  isSelfClosing: boolean
  attrs: AttributeNode[]
  directives: DirectiveNode[]
  children: ChildNode[]
}

export interface TextNode extends Node {
  type: NodeTypes.TEXT
  content: string
  isEmpty: boolean
}

export interface CommentNode extends Node {
  type: NodeTypes.COMMENT
  content: string
}

export interface AttributeNode extends Node {
  type: NodeTypes.ATTRIBUTE
  name: string
  value: TextNode | undefined
}

export interface DirectiveNode extends Node {
  type: NodeTypes.DIRECTIVE
  name: string
  exp: ExpressionNode | undefined
  arg: ExpressionNode | undefined
  modifiers: string[]
}

export interface ExpressionNode extends Node {
  type: NodeTypes.EXPRESSION
  content: string
  isStatic: boolean
}

export interface IfNode extends Node {
  type: NodeTypes.IF
  branches: IfBranchNode[]
}

export interface IfBranchNode extends Node {
  type: NodeTypes.IF_BRANCH
  condition: ExpressionNode | undefined // else
  children: ChildNode[]
}

export interface ForNode extends Node {
  type: NodeTypes.FOR
  source: ExpressionNode
  valueAlias: ExpressionNode
  keyAlias: ExpressionNode
  objectIndexAlias: ExpressionNode
  children: ChildNode[]
}

export interface Position {
  offset: number // from start of file (in SFCs)
  line: number
  column: number
}

// The node's range. The `start` is inclusive and `end` is exclusive.
// [start, end)
export interface SourceLocation {
  start: Position
  end: Position
  source: string
}