const SkipSubTreeObject={};export class ESTreeWalker{constructor(beforeVisit,afterVisit){this._beforeVisit=beforeVisit;this._afterVisit=afterVisit||new Function();this._walkNulls=false;}
static get SkipSubtree(){return SkipSubTreeObject;}
setWalkNulls(value){this._walkNulls=value;}
walk(ast){this._innerWalk(ast,null);}
_innerWalk(node,parent){if(!node&&parent&&this._walkNulls){const result=({raw:'null',value:null});result.type='Literal';node=(result);}
if(!node){return;}
node.parent=parent;if(this._beforeVisit.call(null,node)===ESTreeWalker.SkipSubtree){this._afterVisit.call(null,node);return;}
const walkOrder=_walkOrder[node.type];if(!walkOrder){console.error('Walk order not defined for '+node.type);return;}
if(node.type==='TemplateLiteral'){const templateLiteral=(node);const expressionsLength=templateLiteral.expressions.length;for(let i=0;i<expressionsLength;++i){this._innerWalk(templateLiteral.quasis[i],templateLiteral);this._innerWalk(templateLiteral.expressions[i],templateLiteral);}
this._innerWalk(templateLiteral.quasis[expressionsLength],templateLiteral);}else{for(let i=0;i<walkOrder.length;++i){const entity=node[walkOrder[i]];if(Array.isArray(entity)){this._walkArray(entity,node);}else{this._innerWalk(entity,node);}}}
this._afterVisit.call(null,node);}
_walkArray(nodeArray,parentNode){for(let i=0;i<nodeArray.length;++i){this._innerWalk(nodeArray[i],parentNode);}}}
const _walkOrder={'AwaitExpression':['arguments'],'ArrayExpression':['elements'],'ArrayPattern':['elements'],'ArrowFunctionExpression':['params','body'],'AssignmentExpression':['left','right'],'AssignmentPattern':['left','right'],'BinaryExpression':['left','right'],'BlockStatement':['body'],'BreakStatement':['label'],'CallExpression':['callee','arguments'],'CatchClause':['param','body'],'ClassBody':['body'],'ClassDeclaration':['id','superClass','body'],'ClassExpression':['id','superClass','body'],'ConditionalExpression':['test','consequent','alternate'],'ContinueStatement':['label'],'DebuggerStatement':[],'DoWhileStatement':['body','test'],'EmptyStatement':[],'ExpressionStatement':['expression'],'ForInStatement':['left','right','body'],'ForOfStatement':['left','right','body'],'ForStatement':['init','test','update','body'],'FunctionDeclaration':['id','params','body'],'FunctionExpression':['id','params','body'],'Identifier':[],'ImportDeclaration':['specifiers','source'],'ImportExpression':['source'],'ExportAllDeclaration':['source'],'ExportDefaultDeclaration':['declaration'],'ExportNamedDeclaration':['specifiers','source','declaration'],'IfStatement':['test','consequent','alternate'],'LabeledStatement':['label','body'],'Literal':[],'LogicalExpression':['left','right'],'MemberExpression':['object','property'],'MethodDefinition':['key','value'],'NewExpression':['callee','arguments'],'ObjectExpression':['properties'],'ObjectPattern':['properties'],'ParenthesizedExpression':['expression'],'Program':['body'],'Property':['key','value'],'RestElement':['argument'],'ReturnStatement':['argument'],'SequenceExpression':['expressions'],'SpreadElement':['argument'],'Super':[],'SwitchCase':['test','consequent'],'SwitchStatement':['discriminant','cases'],'TaggedTemplateExpression':['tag','quasi'],'TemplateElement':[],'TemplateLiteral':['quasis','expressions'],'ThisExpression':[],'ThrowStatement':['argument'],'TryStatement':['block','handler','finalizer'],'UnaryExpression':['argument'],'UpdateExpression':['argument'],'VariableDeclaration':['declarations'],'VariableDeclarator':['id','init'],'WhileStatement':['test','body'],'WithStatement':['object','body'],'YieldExpression':['argument']};