Is there a type in TypeScript for anything except functions?

Question

I would like to express that a paremeter should be an object or a simple value type (number, bool, string, etc.), but not a function.

If I use Object, t

Answer 1

With typescript 1.8, you can get pretty close if you define function as something that has all 4 properties: caller, bind, apply and call:

interface NoCaller {
    caller?: void;
}
interface NoBind {
    bind?: void;
}
interface NoApply {
    apply?: void;
}
interface NoCall {
    call?: void;
}

type NotAFunction = NoCaller | NoBind | NoApply | NoCall; // if it fails all 4 checks it's a function


function check(t: T) {
    // do something
}

function f() {
}

class T {
}

var o = new T();

check({});
check(o);
check({caller: 'ok', call: 3, apply: this});

//check(f); // fails
//check(T); // also fails: classes are functions, you can't really escape from javascript

Surprisingly, the error message is not that bad:

error TS2345: Argument of type '() => void' is not assignable to parameter of type 'NoCaller | NoBind | NoApply | NoCall'.
  Type '() => void' is not assignable to type 'NoCall'.
    Types of property 'call' are incompatible.
      Type '(thisArg: any, ...argArray: any[]) => any' is not assignable to type 'void'.