src/parsetree.js
function pseudoRotateArray (a, rng) {
  var halfLen = a.length / 2, insertAfter = Math.ceil(halfLen) + Math.floor (rng() * Math.floor(halfLen))
  var result = a.slice(1)
  result.splice (insertAfter, 0, a[0])
  return result
}
function pseudoRotateArray (a, rng) {
  var halfLen = a.length / 2, insertAfter = Math.ceil(halfLen) + Math.floor (rng() * Math.floor(halfLen))
  var result = a.slice(1)
  result.splice (insertAfter, 0, a[0])
  return result
}
function pseudoRotateArray ( a , rng ) { var halfLen = a . length / 2 , insertAfter = Math . ceil ( halfLen ) + Math . floor ( rng ( ) * Math . floor ( halfLen ) ) var result = a . slice ( 1 ) result . splice ( insertAfter , 0 , a [ 0 ] ) return result }
pseudoRotateArray moves first item to somewhere in the back half
pseudoRotateArray moves first item to somewhere in the back half