In TypeScript how do I declare an array of functions that accept a string and return a string?

Question

UPDATE - the context of this question was pre-TypeScript 1.4. Since that version, my first guess has been supported by the language. See the update to the a

Answer 1

I figured it out. The problem is that the => for a function type literal is itself merely syntactic sugar and doesn't want to compose with [].

As the spec says:

A function type literal of the form

( ParamList ) => ReturnType

is exactly equivalent to the object type literal

{ ( ParamList ) : ReturnType }

So what I want is:

var h : { (s: string): string; }[]

Complete example:

var f : (string) => string

f = x => '(' + x + ')';

var h : { (s: string): string; }[]

h = [];

h.push(f);

Update:

Judging from this changeset parentheses will be allowed in type declarations in 1.4, so the "first guess" in the question will also be correct:

var h: ((string) => string)[]

Further Update It is in 1.4!