Interface Walker

Helper to analyze an AST.

interface Walker {
    child(childIndex: number): undefined | ASTNode;
    children(): ASTNode[];
    childrenCount(): number;
    current: ASTNode;
    currentIndex: number;
    hasChild(childIndex: number): boolean;
    hasChildren(): boolean;
    hasNextSibling(): boolean;
    hasParent(): boolean;
    hasPrevSibling(): boolean;
    isROOT(node?: ASTNode): boolean;
    parent(): undefined | ASTNode;
    parents: ASTNode[];
    queryOptions: ComplexQueryOptions;
    ROOT: ASTNode;
    sibling(offsetFromCurrentPosition: number): undefined | ASTNode;
    toAncestor(offset: number): undefined | Walker;
    toChild(childIndex: number): undefined | Walker;
    toFirstChild(): undefined | Walker;
    toLastChild(): undefined | Walker;
    toNextSibling(): undefined | Walker;
    toParent(): undefined | Walker;
    toPrevSibling(): undefined | Walker;
    toROOT(): Walker;
    toSibling(offsetFromCurrentPosition: number): undefined | Walker;
    walk(cb: VisitCallback, scope?: any): void;
    walkChildren(cb: ChildVisitCallback, scope?: any): void;
    walker(): Walker;
    walkPostOrder(cb: VisitCallback, scope?: any): void;
    walkPreOrder(cb: VisitCallback, scope?: any): void;
}

Properties

current currentIndex parents queryOptions ROOT

Methods

child children childrenCount hasChild hasChildren hasNextSibling hasParent hasPrevSibling isROOT parent sibling toAncestor toChild toFirstChild toLastChild toNextSibling toParent toPrevSibling toROOT toSibling walk walkChildren walker walkPostOrder walkPreOrder

Properties

current

current: ASTNode

Current ASTNode.

currentIndex

currentIndex: number

Index of the current node in the parent's children.

parents

parents: ASTNode[]

All parents of the current node.

queryOptions

queryOptions: ComplexQueryOptions

Global query options.

ROOT

ROOT: ASTNode

Root of the AST

Methods

child

  • child(childIndex: number): undefined | ASTNode

  • Function to pick the child at a given index.

    Parameters

    • childIndex: number

    Returns undefined | ASTNode

children

  • children(): ASTNode[]

  • Function to pick the child nodes of the current node.

    Returns ASTNode[]

childrenCount

  • childrenCount(): number

  • Function to get the number of children of the current node.

    Returns number

hasChild

  • hasChild(childIndex: number): boolean

  • Function to check if the child at a given index exists.

    Parameters

    • childIndex: number

    Returns boolean

hasChildren

  • hasChildren(): boolean

  • Function to check if the current node has children.

    Returns boolean

hasNextSibling

  • hasNextSibling(): boolean

  • Function to check if the next sibling exists.

    Returns boolean

hasParent

  • hasParent(): boolean

  • Function to check if the current node has a parent.

    Returns boolean

hasPrevSibling

  • hasPrevSibling(): boolean

  • Function to check if the previous sibling exists.

    Returns boolean

isROOT

  • isROOT(node?: ASTNode): boolean

  • Function to check if a given node is the root of the AST. If no parameter is provided, this function will test if the walker is at the root position of the AST.

    Parameters

    Returns boolean

parent

  • parent(): undefined | ASTNode

  • Function to pick the parent of the current node.

    Returns undefined | ASTNode

sibling

  • sibling(offsetFromCurrentPosition: number): undefined | ASTNode

  • Function to pick a sibling at an offset relative to the current position.

    Parameters

    • offsetFromCurrentPosition: number

    Returns undefined | ASTNode

toAncestor

  • toAncestor(offset: number): undefined | Walker

  • Function to move the walker to an ancestor with given an offset. e.g. 1=direct parent, 2 = grandparent, ...

    Parameters

    • offset: number

    Returns undefined | Walker

toChild

  • toChild(childIndex: number): undefined | Walker

  • Function to move the walker to the child at a given index.

    Parameters

    • childIndex: number

    Returns undefined | Walker

toFirstChild

  • toFirstChild(): undefined | Walker

  • Function to move the walker to the first child.

    Returns undefined | Walker

toLastChild

  • toLastChild(): undefined | Walker

  • Function to move the walker to the last child.

    Returns undefined | Walker

toNextSibling

  • toNextSibling(): undefined | Walker

  • Function to move the walker to the next sibling.

    Returns undefined | Walker

toParent

  • toParent(): undefined | Walker

  • Function to move the walker to the current parent.

    Returns undefined | Walker

toPrevSibling

  • toPrevSibling(): undefined | Walker

  • Function to move the walker to the previous sibling.

    Returns undefined | Walker

toROOT

  • toROOT(): Walker

  • Function to move the walker to the AST root.

    Returns Walker

toSibling

  • toSibling(offsetFromCurrentPosition: number): undefined | Walker

  • Function to move the walker to a sibling with an offset relative to the current position.

    Parameters

    • offsetFromCurrentPosition: number

    Returns undefined | Walker

walk

  • walk(cb: VisitCallback, scope?: any): void

  • Function to walk over the AST. The visitor callback is called twice for every node.

    Parameters

    Returns void

walkChildren

  • walkChildren(cb: ChildVisitCallback, scope?: any): void

  • Function to walk over all children.

    Parameters

    Returns void

walker

  • walker(): Walker

  • Function to create a new walker at the current node position.

    Returns Walker

walkPostOrder

  • walkPostOrder(cb: VisitCallback, scope?: any): void

  • Function to walk over the AST. The visitor callback is called once for every node. Parents are visited after the children.

    Parameters

    Returns void

walkPreOrder

  • walkPreOrder(cb: VisitCallback, scope?: any): void

  • Function to walk over the AST. The visitor callback is called once for every node. Parents are visited before the children.

    Parameters

    Returns void

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