Exponentiation Operator: **

exponentiation.md

Exponentiation Operator

Performs exponential calculation on operands. Same algorithm as Math.pow(x, y)

• Commonly used in albegra, geometry, physics and robotics.
• Nice to have "inline" operator

Prior Art

• Python
  • math.pow(x, y)
  • x ** y
• CoffeeScript
  • x ** y
• F#
  • x ** y
• Ruby
  • x ** y
• Perl
  • x ** y
• Lua, Basic, MATLAB, etc.
  • x ^ y

Usage

// x ** y

let squared = 2 ** 2;
// same as: 2 * 2

let cubed = 2 ** 3;
// same as: 2 * 2 * 2

// x **= y

let a = 2;
a **= 2;
// same as: a = a * a;



let b = 3;
b **= 3;
// same as: b = b * b * b;

ExponentiationExpression : 
  UnaryExpression
  UnaryExpression ** ExponentiationExpression
  
MultiplicativeExpression :
  ExponentiationExpression
  MultiplicativeExpression * ExponentiationExpression
  MultiplicativeExpression / ExponentiationExpression
  MultiplicativeExpression % ExponentiationExpression


AssignmentOperator : one of
  =
  *=
  /=
  %=
  +=
  -=
  <<=
  >>=
  >>>=
  &=
  ^=
  |=
  **=

Status

Implemented as option in Traceur

Reviewed By:

• Erik Arvidsson
• Dmitry Lomov

Is the right recursive version because of desired operator right associativity so "a ** b ** c" -> "(a ** (b ** c))"?
Most ECMAScript grammar productions are written as left recursive, but of course, that would make "a ** b ** c" -> "((a ** b) ** c)".