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import * as a from './syntax/ast.ts';import { AstDefaultMapper, IAstPartialMapper, astMapper, IAstMapper } from './ast-mapper.ts';import { ReplaceReturnType } from './utils.ts';


export type IAstPartialVisitor = { [key in keyof IAstPartialMapper]: ReplaceReturnType<IAstPartialMapper[key], any> }export type IAstFullVisitor = {    [key in keyof IAstPartialVisitor]-?: IAstPartialVisitor[key];}
export type IAstVisitor = IAstFullVisitor & {    super(): IAstVisitor;}

class Visitor {    mapper?: IAstMapper;    visitor?: IAstPartialVisitor;
    super() {        return new SkipVisitor(this);    }}
// =============== auto implement the mapperconst mapperProto = AstDefaultMapper.prototype as any;for (const k of Object.getOwnPropertyNames(mapperProto)) {    const orig = mapperProto[k] as Function;    if (k === 'constructor' || k === 'super' || typeof orig !== 'function') {        continue;    }    Object.defineProperty(Visitor.prototype, k, {        configurable: false,        get() {            return function (this: Visitor, ...args: any[]) {                const impl = (this.visitor as any)[k] as Function;                if (!impl) {                    // just ignore & forward call to mapper                    return orig.apply(this, args);                }                // return first argument                // ...which means "I dont wana change anything"                //    in the ast-modifier language.                impl.apply(this.visitor, args);                return args[0];            }        }    })}

// ====== auto implement the skip mechanismclass SkipVisitor {    constructor(readonly parent: Visitor) {    }}
for (const k of Object.getOwnPropertyNames(mapperProto)) {    const orig = mapperProto[k] as Function;    if (k === 'constructor' || k === 'super' || typeof orig !== 'function') {        continue;    }    Object.defineProperty(SkipVisitor.prototype, k, {        configurable: false,        get() {            return function (this: SkipVisitor, ...args: []) {                return orig.apply(this.parent, args);            }        }    });}
/** * Builds an AST visitor based on the default implementation, merged with the one you provide. * * Example of visitor which counts references to a column 'foo': * * ```ts * let cnt = 0; * const visitor = astVisitor(v => ({ *      ref: r => { *          if (r.name === 'foo') { *              cnt++; *          } *          v.super().ref(r); *      } *  })); * * visitor.statement(myStatementToCount); * console.log(`${cnt} references to foo !`); * ``` */export function astVisitor<T extends IAstPartialVisitor = IAstPartialVisitor>(visitorBuilder: (defaultImplem: IAstVisitor) => T): IAstVisitor {    return astMapper(m => {        const ret = new Visitor();        ret.mapper = m;        ret.visitor = visitorBuilder(ret as any);        return ret as any;    })}