11. Operators

SS includes all of the numeric operators from C, with the same precedence, associativity, and meaning.

SS also includes operators ** for exponentiation, ^^ for logical XOR, => for logical implication, <=> for logical equivalence, and the logical assignment operators &&=, ^^=, and ||=.

The keywords NOT, AND, XOR, OR, IMP, and EQU, case-insensitive, may also be used to represent the logical operators.

SS does not include the C array, structure, and pointer operators.

The operators are:

  ()            parentheses, (expr)
  ++            postfix increment, x++
  --            postfix decrement, x--
  ++            prefix increment, ++x
  --            prefix decrement, --x
  -             unary minus
  +             unary plus
  ~             bitwise NOT
  !             logical NOT
  NOT           logical NOT
  (int)         cast
  (long)        cast
  (double)      cast
  **            exponentiation, x**y == pow(x,y)
  *             multiplication
  /             division
  %             mod, x%y == fmod(x,y)
  +             addition
  -             subtraction
  <<            shift left, x<<y == x*2**y
  >>            shift right, x>>y == x/2**y
  <             less than
  <=            less than or equal
  >             greater than
  >=            greater than or equal
  ==            equal
  !=            not equal
  &             bitwise AND
  ^             bitwise XOR
  |             bitwise OR
  &&            logical AND
  AND           logical AND
  ^^            logical XOR
  XOR           logical XOR
  ||            logical OR
  OR            logical OR
  =>            logical implication
  IMP           logical implication
  <=>           logical equivalence
  EQU           logical equivalence
  ?:            conditional operator, e1 ? e2 : e3
  =             assignment
  *=            multiplication assignment
  /=            division assignment
  %=            mod assignment
  +=            addition assignment
  -=            subtraction assignment
  <<=           shift left assignment
  >>=           shift right assignment
  &=            bitwise AND assignment
  ^=            bitwise XOR assignment
  |=            bitwise OR assignment
  &&=           logical AND assignment
  ^^=           logical XOR assignment
  ||=           logical OR assignment
  ,             comma operator

The bit shift operators <<, <<=, >>, and >>= are implemented for floating-point using ldexp() to adjust the binary exponent by the specified power of 2. For the other bitwise operators, the floating-point operands are converted to long integers to perform the operations.

For the logical operators, zero is false and anything non-zero is true. The result of a logical or comparison operation is 0 or 1. So, for example, 7==3 produces 0, but 7<=>3 produces 1.

Operator associativity is left-to-right (LR) or right-to-left (RL). The following table lists all of the operators in decreasing order of precedence:

  Assoc.  Operators
  ------  ---------
  LR      ()  ++  --  {postfix}
  RL      !   ~   ++  --  +  -  (cast)
  RL      **
  LR      *   /   %
  LR      +   -
  LR      <<  >>
  LR      <   <=  >  >=
  LR      ==  !=
  LR      &
  LR      ^
  LR      |
  LR      &&
  LR      ^^
  LR      ||
  LR      =>
  LR      <=>
  RL      ?:
  RL      =  +=  -=  *=  /=  %=  &=  ^=  |=  &&=  ^^=  ||=  <<=  >>=
  LR      ,