Type Alias Compression

Type Alias Compression Protocol (Generic Signature Normalization)

Overview

When writing enterprise applications in TypeScript, Python, or Rust, complex nested generic signatures (e.g., Promise<AxiosResponse<PaginatedResponse<UserProfileDTO>>>) are frequently repeated across 10 to 20 method definitions in a single module.

Repeating nested generic signatures causes:

1. Severe Token Multiplication: Repeating an 80-character generic signature across 15 functions burns 400+ output tokens on syntax boilerplate.
2. Maintenance Drift: Changing the underlying response envelope requires mutating 15 separate function signatures across the file.
3. Cognitive Clutter: The actual function argument names are pushed off-screen by long type annotations.

The Type Alias Compression Protocol extracts common nested generic patterns into concise top-level type aliases (type Res<T> = ...), normalizing signatures to 1 to 2 clean tokens.

Repetitive Nested Generics vs. Compressed Type Aliases

┌─────────────────────────────────────────────────────────────┐
│                 Type Signature Token Density                │
│                                                             │
│  Repetitive Nested Generics (15 Methods / 420 Tokens):      │
│  export async function getUser(id: string):                 │
│    Promise<AxiosResponse<ApiResponse<PaginatedResult<User>>>>{...}│
│  export async function getOrg(id: string):                  │
│    Promise<AxiosResponse<ApiResponse<PaginatedResult<Org>>>>{...} │
│  ↳ 420 tokens billed purely repeating identical generic wraps│
│                                                             │
│  Compressed Type Alias (1 Definition / 65 Tokens):          │
│  type ApiPage<T> = Promise<AxiosResponse<ApiResponse<PaginatedResult<T>>>>;│
│  export async function getUser(id: string): ApiPage<User> {...}│
│  export async function getOrg(id: string): ApiPage<Org> {...} │
│  ↳ 65 clean tokens (84.5% Reduction!), single point of change│
└─────────────────────────────────────────────────────────────┘

Multi-Language Type Alias Compression Recipes

1. TypeScript / JavaScript

// 1. Define High-Frequency Aliases at Top of File
export type AsyncResult<T> = Promise<{ data: T; error: null } | { data: null; error: string }>;
export type Handler<TReq, TRes> = (req: Request<TReq>, res: Response<TRes>) => Promise<void>;
export type ID = string | number;

// 2. Ultra-Clean Method Signatures
export async function fetchUser(id: ID): AsyncResult<User> { ... }
export async function updateProfile(id: ID, payload: UserDto): AsyncResult<User> { ... }

2. Python 3.12+ (PEP 695 Type Aliases)

from typing import Callable, Coroutine, Any

# Python 3.12 native type statement
type JsonResult[T] = Coroutine[Any, Any, dict[str, T]]
type MiddlewareFn = Callable[[Request, Callable], Response]

async def get_user_profile(user_id: str) -> JsonResult[UserProfile]:
    ...

3. Rust Type Aliasing

use std::result::Result as StdResult;

// Aliasing heavy error types across the crate
pub type Result<T> = StdResult<T, AppEngineError>;
pub type UserMap = std::collections::HashMap<String, UserProfile>;

pub fn get_user(id: &str) -> Result<UserProfile> { ... }

Benchmark Comparison

Generating a standard 12-method REST API controller:

Agent Operational Directive

MANDATORY: When a nested generic type signature is used $\ge 2$ times in a file or module, agents must extract it into a top-level type alias (type Result<T> = ...). Never repeat multi-layered generic chains across function signatures.