tsts

Experiments on typescript compiler api features.

Usage:

npm i https://github.com/Morglod/tsts
npm i ttypescript

Specify in tsconfig.json

"compilerOptions": {
    "plugins": [
        { "transform": "tsts/src/transformers/comptime.ts", "type": "checker" }
    ],
}

Build with ttsc as:

"scripts": {
    "build": "ttsc"
},

Build:

npm run build

Features

• Comptime calculations
• Recursive comptime with generic types
• Compile time communication
• Macro-like eval comptimeEval
• Overload decorator overloadOf

comptime

Example of comptime calculations:

Source:

function sum(a: number, b: number) {
    return a + b;
}

function comptimeSum() {
    const numbers = [ 1, 2, 3, 4, 5, 6, 7, 8 ];
    const result = comptime(() => {
        return numbers.reduce((total, x) => sum(total, x), 0);
    });

    console.log(result);

    return result;
}

comptime(() => {
    return comptimeSum();
});

Result:

function comptimeSum() {
    const numbers = [1, 2, 3, 4, 5, 6, 7, 8];
    const result = (() => { return (36); })();
    console.log(result);
    return result;
}

(() => { return (36); })();

Plans

User-level compiler macro definition

__compilerJob($compiler => {
    $compiler.setMacro('__inline', ($compiler, node) => {
        // inline node here
    });
});

function foo(a,b) {
    console.log(a + b);
}

__inline(foo, 10, 20);

Result

console.log(10 + 20);

comptime & __compilerJob stability & error checking

Currently it works by code travel-extraction.
There are a lot of cases where it works bad (like for argument expression eval)

pure function decorator

Check if function is pure (without side effects).

May be used for:

• Safe comptime calls
• Translate TypeScript libraries to other languages (llvm)