Numeric Types

Syntax#

Real numbers must begin with one or more digits followed by a period followed by one or more digits.
~ is the operator to denote negative numbers
div is the operator for integer division.
/ is the operator for real division.

Integer

Integer Basics

Standard ML of New Jersey v110.78 [built: Thu Jul 23 11:21:58 2015]
- 6;
val it = 6 : int
- ~6;
val it = ~6 : int
- 6 + ~6;
val it = 0 : int

Integer Division

- 6 div 3;
val it = 2 : int
- 6 div 4;
val it = 0 : int
- 3 div 6;
val it = 0 : int

Integer Value Bounds

Using Integer Basis Library Functions

- Int.maxInt;
val it = SOME 1073741823 : int option
- Int.minInt;
val it = SOME ~1073741824 : int option

Real

Real Number Basics

- 6.0;
val it = 6.0 : real
- ~6.0;
val it = ~6.0 : real
- 6.0 + ~6.0;
val it = 0.0 : real
- 6.0 / 3.0;
val it = 2.0 : real
- 4.0 / 6.0;
val it = 0.666666666667 : real

Real Value Bounds

Using Real Basis Library Functions

- Real.maxFinite;
val it = 1.79769313486E308 : real
- Real.minPos;
val it = 4.94065645841E~324 : real
- Real.minNormalPos;
val it = 2.22507385851E~308 : real

Infinity

- Real.posInf;
val it = inf : real
- Real.negInf;
val it = ~inf : real

Coercion of Real Values to Integers

Rounding

Values midway between two integers go toward the nearest even value.

- round(4.5);
val it = 4 : int
- round(3.5);
val it = 4 : int

Truncation

val it = 4 : int
- trunc(4.5);
val it = 4 : int
- trunc(3.5);
val it = 3 : int

Floor and Ceiling

- ceil(4.5);
val it = 5 : int
- floor(4.5);
val it = 4 : int

Arithmetic Operator Error with Mixed Numeric Types

Cannot add Integer and Real*

- 5 + 1.0;
stdIn:1.2-10.4 Error: operator and operand don't agree [overload conflict]
  operator domain: [+ ty] * [+ ty]
  operand:         [+ ty] * real
  in expression:
    5 + 1.0

Coersion of Integer Value to Real

- real(6);
val it = 6.0 : real