- (minuend subtrahend -- difference)

Inputs

• minuend: Left operand from which the right operand is subtracted.
• subtrahend: Right operand subtracted from the minuend.

Outputs

• difference: Difference object.

This builtin accepts whole and real numbers. Both inputs are dereferenced and must be non-NIL. The operands must have the same schema.

Behavior

• Whole-number schemas use integer subtraction semantics.
• Real schemas use floating-point subtraction semantics.
• If both operands are known at compile time, the result is computed at compile time.
• If the subtrahend is known 0, the result follows the minuend's value and schema.
• If the minuend is known 0 and the schema is real, the result preserves the real schema of the subtrahend. If that subtrahend is unknown, the result remains unknown.
• Otherwise, the builtin produces an unknown result of the same schema.

Example

{} () {} [
  unknownReal: 2.5r32 dynamic;

  "-- int32 --" printCompilerMessage
  10 3 - printStack _:;
  7 0 - printStack _:;

  "-- zero with unknown real32 --" printCompilerMessage
  0.0r32 unknownReal - printStack _:;

  "-- real32 --" printCompilerMessage
  0.0r32 2.5r32 - printStack _:;
  5.0r32 2.5r32 - printStack _:;
] "main" exportFunction

Expected Output During Compilation

-- int32 --
7
7
-- zero with unknown real32 --
Real32
-- real32 --
-2.5r32
2.5r32

See also

• * builtin (multiplicand multiplier -- product) Multiplies two numeric objects.
• + builtin (left right -- sum) Adds two numeric objects.
• / builtin (dividend divisor -- quotient) Divides numeric objects within the same schema; Whole division stays whole, while Real schemas use floating division.
• mod builtin (dividend divisor -- remainder) Computes the remainder of numeric division; signed Int, unsigned Nat, and Real objects each follow their own remainder semantics.
• neg builtin (object -- negatedValue) Negates a signed Int or Real object and keeps the same schema.