arkts-syntax-assistant

name arkts-syntax-assistant description ArkTS syntax, migration, and optimization guide for HarmonyOS/OpenHarmony development. Triggers on: .ets files, ArkTS keywords, HarmonyOS/OpenHarmony context, @ohos packages. Help with syntax reference, TypeScript migration, performance optimization, compile errors, state management, component development, and language-specific questions. license MIT tags ["arkts","harmonyos","typescript","migration","development","syntax"] ArkTS Syntax Assistant 中文文档 Overview ArkTS is the default development language for OpenHarmony applications. It builds upon TypeScript with enhanced static typing to improve program stability and performance. Core Features Static Typing : All types determined at compile time, reducing runtime checks No Dynamic Object Layout : Object structure fixed at compile time, cannot be modified at runtime Restricted Operators : Some operator behaviors are restricted to encourage clearer code semantics No Structural Typing : Structural typing is currently not supported Reference Documentation Scenario Document Syntax Learning references/en/introduction-to-arkts.md Quick Overview references/en/arkts-get-started.md TS Migration references/en/typescript-to-arkts-migration-guide.md Migration Background references/en/arkts-migration-background.md Performance references/en/arkts-high-performance-programming.md More Cases references/en/arkts-more-cases.md Workflows 1. Syntax Questions User Question -> Identify Question Type -> Consult Documentation -> Provide Code Example Common Syntax Questions : Variable declaration -> Use let / const with explicit type or inference Function definition -> Supports optional parameters, defaults, rest parameters, arrow functions Classes and interfaces -> Must initialize fields, supports inheritance and implementation Generics -> Supports constraints and default values Null safety -> Nullable types ((T | null)), non-null assertion ((!)), optional chaining ((?.)) 2. TypeScript Migration Identify TS Code -> Check Incompatible Features -> Consult Migration Rules -> Provide ArkTS Alternative Key Migration Rules Quick Reference : TypeScript ArkTS Alternative var x let x any / unknown Specific types {n: 42} object literal Define class/interface first [index: T]: U index signature Record<T, U> A & B intersection type interface C extends A, B function(){} function expression () => {} arrow function <Type>value type assertion value as Type Destructuring [a, b] = arr Individual access arr[0] , arr[1] for..in for loop or for..of Constructor parameter properties Explicit field declaration 3. Performance Optimization Analyze Code -> Identify Performance Issues -> Consult Optimization Guide -> Provide Solutions High-Performance Programming Key Points : Declarations : Use const for invariants; avoid mixing integer and float Loops : Extract loop invariants; avoid numeric overflow Functions : Parameter passing preferred over closures; avoid optional parameters Arrays : Use TypedArray for numeric values; avoid sparse arrays and union type arrays Exceptions : Avoid throwing in loops; use return values instead 4. Compile Error Resolution Get Error Message -> Search Migration Rules -> Find Related Case -> Provide Fix Common Questions Q: How to handle JSON.parse return value? // Error let data = JSON . parse (str); // Correct let data : Record < string , Object > = JSON . parse (str); Q: How to define object types? // TypeScript syntax (not supported in ArkTS) type Person = { name : string , age : number } // ArkTS syntax interface Person { name : string ; age : number ; } // Using object literal let p : Person = { name : 'John' , age : 25 }; Q: How to replace globalThis? // Error globalThis. value = 'xxx' ; // Use singleton pattern export class GlobalContext { private constructor ( ) {} private static instance : GlobalContext ; private _objects = new Map < string , Object >(); public static getContext (): GlobalContext { if (! GlobalContext . instance ) { GlobalContext . instance = new GlobalContext (); } return GlobalContext . instance ; } getObject ( key : string ): Object | undefined { return this . _objects . get (key); } setObject ( key : string , value : Object ): void { this . _objects . set (key, value); } } Q: How to handle error types in catch? // Error try {} catch ( e : BusinessError ) {} // Correct try {} catch (error) { let e : BusinessError = error as BusinessError ; } Q: How to use Record type? // TypeScript index signature function foo ( data : { [key: string ]: string } ) {} // ArkTS Record function foo ( data : Record < string , string > ) {} // Usage example let map : Record < string , number > = { 'John' : 25 , 'Mary' : 21 , }; Q: How to replace constructor signatures with factory functions? // TypeScript constructor signature type ControllerCtor = { new ( value : string ): Controller ; } // ArkTS factory function type ControllerFactory = () => Controller ; class Menu { createController : ControllerFactory = () => { return new Controller ( 'default' ); } } Prohibited Standard Library APIs The following are prohibited in ArkTS: Global : eval Object : __proto__ , defineProperty , freeze , getPrototypeOf , etc. Reflect : apply , construct , defineProperty , etc. Proxy : All handler methods Build Scripts The scripts directory provides quick compilation scripts for ArkTS projects (including dependency installation): Platform Script Purpose macOS/Linux scripts/run.sh Execute ohpm install + hvigorw assembleApp Windows scripts/run.ps1 Execute ohpm install + hvigorw assembleApp Usage: # macOS/Linux bash scripts/run.sh # Windows PowerShell .\scripts\run.ps1 Script execution steps: Install dependencies ( ohpm install --all ) Build project ( hvigorw assembleApp ) Mandatory Requirements CRITICAL : When this skill generates ArkTS code, the following workflow MUST be followed: Compilation Verification : After generating code, you MUST compile the project using the build scripts: macOS/Linux: bash scripts/run.sh Windows: .\scripts\run.ps1 Retry Strategy : If compilation fails: Analyze the error output Fix the issue and retry compilation Maximum of 3 compilation attempts User Intervention : After 3 failed compilation attempts, use AskUserQuestion : Question: Compilation failed after 3 attempts. How would you like to proceed? Options: - Continue retrying (attempt another fix) - Manual intervention (I'll wait for your guidance) - Skip compilation (proceed without verification) Error Reporting : Always show the full compilation error output when failures occur. Answer Guidelines Prioritize code examples : Show correct vs incorrect syntax comparison Reference official documentation : For detailed explanations, guide users to consult corresponding documents in references/ Explain reasons : Explain why ArkTS has this restriction (performance, stability) Provide alternatives : For unsupported features, provide feasible alternatives License MIT License - see LICENSE.txt