OperatorAssociativity.purs

module Main where

import Control.Monad.Eff
import Debug.Trace

foreign import data Assert :: !

foreign import assert
  """
  function assert(x) {
    return function(desc) {
      return function() {
        if (!x) throw new Error('assertion (' + desc + ') failed');
        return {};
      };
    };
  }
  """ :: forall e. Boolean -> String -> Eff (assert :: Assert | e) Unit

bug :: Number -> Number -> Number
bug a b = 0 - (a - b)

foreign import explode
  """
  function explode() {
    throw new Error('Assertion failed!');
  }
  """ :: forall eff a. Eff eff a

main = do
    assert (bug 0 2 == 2)       "bug 0 2 == 2"
    assert (0 - (0 - 2) == 2)   "0 - (0 - 2) == 2"
    assert (0 - (0 + 2) == -2)  "0 - (0 + 2) == -2"

    assert (6 / (3 * 2) == 1)   "6 / (3 * 2) == 1"
    assert ((6 / 3) * 2 == 4)   "(6 / 3) * 2 == 4"

    assert (not (1 < 0) == true) "not (1 < 0) == true"
    assert (not ((negate 1) < 0) == false) "not ((negate 1) < 0) == false"

    assert (negate (1 + 10) == -11) "negate (1 + 10) == -11"

    assert (2 * 3 / 4 == 1.5) "2 * 3 / 4 == 1.5"
    assert (1 * 2 * 3 * 4 * 5 / 6 == 20) "1 * 2 * 3 * 4 * 5 / 6 == 20"

    assert (1 + 10 - 5 == 6) "1 + 10 - 5 == 6"
    assert (1 + 10 * 5 == 51) "1 + 10 * 5 == 51"
    assert (10 * 5 - 1 == 49) "10 * 5 - 1 == 49"

    trace "Success!"