TS-Type=JS ?

- Type = #fec_tokyo 2025/09/21 ?

JS + Type

Google Closure Compiler

??

main.c compile a.out exec > "hello world" main.java compile main.class exec > "hello world" VM main.ts compile main.js exec > "hello world" VM

Type

Type ● syntax ● check/infer

main.ts compile main.js exec > "hello world" VM TypeCheck TypeStrip

compile 🤔

compile 🤔

de-sugar compile minify 🤔

de-sugar compile 🤔 y nif mi

Enums Namespaces Decorators ... 🤔 Extending Type Language... ● syntax ● check/infer

Enums Namespaces Decorators ... Type Not Recommended ?? ● syntax ● check/infer 🤔

Enums Namespaces Decorators ... Type ● syntax ● check/infer 🤔

main.ts compile main.js exec > "hello world" VM TypeCheck TypeStrip

TSC TypeCheck isTypeCheck too Slow main.ts compile main.js exec > "hello world" VM TypeStrip

Chance To 🤩 Re-Implement !! Not 😱 Documented ...

TypeScript Parsers TS/JS Rust Go 🤔 Zig Why so many Parsers ... ?

Performance Battle

TypeStrip = Type Check-Less Compile tsc swc

TSC (Language Server) P LS main.ts TypeCheck compile main.js exec > "hello world" VM TypeStrip

TSC (Language Server) P LS main.ts TypeCheck 🤔 run TypeStrip Run on v8 is Deno a TypeScript runtine ?

TSC (Language Server) TypeStrip TypeCheck Run on v8 P LS run TypeStrip main.ts run Run on v8 🤔 is Node a TypeScript runtine ?

😳

Don't we consider Type only as an annotation? 🤔

Type as Annotation

Stage: 1

class Person { name: string; constructor(name: string) { this.name = name; } TypeScript getGreeting(): string { return Hello, ${this.name}; } }

Types as Annotation class Person { name /*: string*/; constructor(name /*: string*/) { this.name = name; } getGreeting()/*: string*/ { return Hello ${this.name}; } }

Standardise TypeScript in ECMA

const name: string = "Jxck" Treat as Comment

const name: ここはどうせコメント なので何を書いても 怒られない??🤔 = "Jxck"

Brand new World !! 🤩🤩🤩

SQL as Comments const user: logging(warn) = "Jxck"

Cooments as Comments const regist: (FIXME) regist って 日本語は無いって 何度言ったら、、 = true

Decorator as comments const user: select id, name from Users where user id = "Jxck"

Brain f**k as comments const user: ++++++++[>++++++++++++++<-]>+++.< >+.< >--.< >---------.< >+++++.< >-------.< = "Jxck"

TSC (Language Server) TypeStrip Run on v8 TypeCheck P LS run TypeStrip Run on v8 main.ts run TypeStrip Run on v8 run 🤔 Then is Browser a TypeScript runtine ?

main.c compile a.out exec > "hello world" main.java compile main.class exec > "hello world" VM main.ts TypeStrip 🤔 main.js exec > "hello world" VM Language... ?

🤔 Type as External Annotation ?

Type ● check/infer ● syntax ● lint/fmt ● tree shake ● bundle ● minify ● JSX ● Testing ● ... Enums Namespaces Decorators ...

TSC (Language Server) P LS TypeCheck TS CodeBases build bundle.js exec > "hello world" VM ● TypeStrip ● Treshake ● Bundle ● Minify

Type ● check/infer ● syntax ● lint/fmt ● tree shake ● bundle ● minify ● JSX ● Testing ● ... 💥The Wild West💥of frontend toolchains !! 🤩🤩🤩

TSC (Language Server) P LS TypeCheck TS CodeBases build bundle.js exec > "hello world" VM ● TypeStrip ● Treshake ● Bundle ● Minify

TypeScript Parsers TS/JS Rust Go Zig 😳‼

TypeScript Parsers TS/JS Rust Go Zig Great Migration ? ��

● AI 出すと互換性の問題があるからあまりやりたくない。 ● IPC なら中⾝は隠せるからあり。 ● そもそも Go 実装ツールためではなく、 JS のためにやってる。 ● どうしてもやりたいなら fork して好きにイジるのがいい。 ● バージョン管理での合意が取れるならまだ、、でも難しくない？

• https://github.com/microsoft/typescript-go/discussions/481

TypeScript Parsers TS/JS Rust Go 🤔 Zig Fast parser is still required...

TSC (Language Server) P LS TypeCheck TS CodeBases build bundle.js exec > "hello world" VM ● TypeStrip ● Treshake ● Bundle ● Minify

Type Aware Linting TS CodeBases Type Aware Parse 🤔 Who covers here ? Lint TS CodeBases

Type Aware Linting TS CodeBases Type Aware Parse Lint 🤩 TS CodeBases

TSC (Language Server) P LS TypeCheck TS CodeBases build bundle.js exec > "hello world" Li nt VM TypeCheck ● TypeStrip ● Treshake Type Aware Linting ● Bundle ● Minify

TSC Development (Language Server) Experience P LS TypeCheck TS CodeBases bundle.js build exec > "hello world" Li nt VM TypeCheck ● TypeStrip ● Treshake Type Aware Linting Deployment Experience ● Bundle ● Minify

TypeCheck 🤔

Type ● check/infer ● syntax ● lint/fmt ● tree shake ● bundle ● minify ● JSX ● Testing ● ... Enums Namespaces Decorators ...

+ Type =

- Type =

+ Type as Annotation =

+ ● TypeCheck ● Lint+Fmt ● Testing = Better DX

Enums Namespaces Decorators ... Despite not being a programming language, Type tried to act like one? ● syntax ● check/infer 🤔

Do we really expect TypeScript to be a programming language? 🤔

We really expect TypeScript to be a Ultra Fast Type Checker !! 🤩