Simplest syntax for a TypeScript lambda that returns an object literal

Question

Consider the JavaScript function:

function(o) { return o.a; } 

In TypeScript, the following shorthand is equivalent:

o => o.a 

Is there a way to apply this shorthand to the following function?

function(o) { return { a: o.a, b: o.b }; } 

The obvious transformation does not work as the opening brace ({) is interpreted as indicating a block is required:

o => { a: o.a, b: o.b }                // doesn't work  o => { return { a: o.a, b: o.b }; }    // works 

Answer 1

There isn't a way to make the grammar interpret the { as an object literal rather than a block statement in this context, but you can use parentheses to force it to be interpreted as an expression:

var x = (t) => ({ n: t });