Language Constructs

• va.foo = 5 + va.bar

  Annotation expression. Bind variable va.foo to the result of evaluating 5 + va.bar.

• if (p) a else b

  The value of the conditional is the value of a or b depending on p. If p is missing, the value of the conditional is missing.

  if (5 % 2 == 0) 5 else 7
  7
  

  if (5 > NA: Int) 5 else 7
  NA: Int
  

• let v1 = e1 and v2 = e2 and … and vn = en in b

  Bind variables v1 through vn to result of evaluating the ei. The value of the let is the value of b. v1 is visible in e2 through en, etc.

  let v1 = 5 and v2 = 7 and v3 = 2 in v1 * v2 * v3
  70