70  * kind of a scope
78    * type of scope
94   export function isGlobalScope(scope: Scope): boolean {
95     return scope.kind === ScopeKind.GLOBAL;
98   export function isFunctionScope(scope: Scope): boolean {
99     return scope.kind === ScopeKind.FUNCTION;
102   export function isClassScope(scope: Scope): boolean {
103     return scope.kind === ScopeKind.CLASS;
106   export function isInterfaceScope(scope: Scope): boolean {
107     return scope.kind === ScopeKind.INTERFACE;
110   export function isEnumScope(scope: Scope): boolean {
111     return scope.kind === ScopeKind.ENUM;
114   export function isObjectLiteralScope(scope: Scope): boolean {
115     return scope.kind === ScopeKind.OBJECT_LITERAL;
119    * get a new scope.
120    * @param name - name of the scope.
121    * @param node - node of a current scope in ast.
122    * @param type - type of the scope.
123    * @param lexicalScope - indicates if the scope is a lexical scope.
124    * @param upper - parent scope of the current scope.
126   export class Scope {  class
127     // scope name
129     // kind of a scope, such as global ,function like, block ..
131     // node of a current scope in ast.
133     // parent scope of current scope
134     parent: Scope | undefined;
135     // sub scopes of current scope
136     children: Scope[];
138     // symbols define in current scope
141     // labels in current scope
152 …structor(name: string, node: Node, type: ScopeKind, lexicalScope: boolean = false, upper?: Scope) {
169      * add a sub scope to current scope
173     addChild(child: Scope): void {
178      * add definition symbol into current scope
190      * add label to current scope
232     scope: Scope;  property
235 …export function createLabel(node: LabeledStatement, scope: Scope, parent?: Label | undefined): Lab…
236     let labelName: string = '$' + scope.labels.length + '_' + node.label.text;
243       'scope': scope,
246     scope.labels.push(label);
260      * do scope analysis
268      * get root scope of a file
270     getRootScope(): Scope;
273      * find block Scope of a node
276     getScopeOfNode(node: Node): Scope | undefined;
281     let root: Scope;
282     let current: Scope;
283     let scopes: Scope[] = [];
306     function getRootScope(): Scope {
518       current = new Scope(scopeName, node, ScopeKind.OBJECT_LITERAL, false, current);
582       root = new Scope(scopeName, node, ScopeKind.GLOBAL, true);
587       // locals of a node(scope) is symbol that defines in current scope(node).
596       current = new Scope(scopeName, node, ScopeKind.CATCH, false, current);
627       current = new Scope(scopeName, node, ScopeKind.INTERFACE, true, current);
642        * if it is an anonymous scope, generate the scope name with a number,
643        * which is based on the order of its child scopes in the upper scope
646       current = new Scope(scopeName, node, ScopeKind.MODULE, true, current);
716         current = new Scope(scopeName, node, ScopeKind.FUNCTION, true, current);
746 …The `current` scope is the function's scope, the `current.parent` scope is where the function is d…
747           `foo` has already added in the parent scope, we need to add `bar` here too.
772       current = new Scope(scopeName, node, ScopeKind.SWITCH, false, current);
780 …* ES6+ class like scope, The members of a class aren't not allow to rename in rename identifiers t…
792         current = new Scope(scopeName, node, ScopeKind.CLASS, true, current);
813       current = new Scope(scopeName, node, ScopeKind.FOR, false, current);
823         // skip direct block scope in function scope
829       current = new Scope(scopeName, node, ScopeKind.BLOCK, false, current);
838       current = new Scope(scopeName, node, ScopeKind.INTERFACE, true, current);
858       current = new Scope(scopeName, node, ScopeKind.ENUM, true, current);
925 …// labels within the same scope are allowed to be duplicated, so label names need to have numberin…
931     function getScopeOfNode(node: Node): Scope | undefined {
941       for (const scope of scopes) {  constant
942         if (scope?.defs.has(sym)) {
943           return scope;