deferred class COMPARABLE

Features exported to INTERNALS_HANDLER

All classes handling COMPARABLE objects with a total order relation should inherit from this class.

Direct parents

non-conformant parents

ANY

Known children

conformant children

CHARACTER, INTEGER_GENERAL, MICROSECOND_TIME, MUTABLE_BIG_INTEGER, NUMBER, REAL_GENERAL, STRING, TIME, UNICODE_STRING

Summary

exported features

Details

is_equal (other: COMPARABLE): BOOLEAN

Is other attached to an object considered equal to current object ?

require

  • other /= Void

ensure

  • trichotomy: Result = (not (Current < other) and not (other < Current))
  • commutative: generating_type = other.generating_type implies Result = other.is_equal(Current)

deferred < (other: COMPARABLE): BOOLEAN

Is Current strictly less than other?

See also >, <=, >=, min, max.

require

  • other_exists: other /= Void

ensure

  • asymmetric: Result implies not (other < Current)

<= (other: COMPARABLE): BOOLEAN

Is Current less than or equal other?

See also >=, <, >, min, max.

require

  • other_exists: other /= Void

ensure

  • definition: Result = (Current < other or is_equal(other))

> (other: COMPARABLE): BOOLEAN

Is Current strictly greater than other?

See also <, >=, <=, min, max.

require

  • other_exists: other /= Void

ensure

  • definition: Result = (other < Current)

>= (other: COMPARABLE): BOOLEAN

Is Current greater than or equal than other?

See also <=, >, <, min, max.

require

  • other_exists: other /= Void

ensure

  • definition: Result = (other <= Current)

in_range (lower: COMPARABLE, upper: COMPARABLE): BOOLEAN

Return True if Current is in range [lower..upper]

See also min, max, compare.

ensure

  • Result = (Current >= lower and Current <= upper)

compare (other: COMPARABLE): INTEGER

If current object equal to other, 0 if smaller, -1; if greater, 1.

See also min, max, in_range.

require

  • other_exists: other /= Void

ensure

  • equal_zero: Result = 0 = is_equal(other)
  • smaller_negative: Result = -1 = (Current < other)
  • greater_positive: Result = 1 = (Current > other)

three_way_comparison (other: COMPARABLE): INTEGER

If current object equal to other, 0 if smaller, -1; if greater, 1.

See also min, max, in_range.

require

  • other_exists: other /= Void

ensure

  • equal_zero: Result = 0 = is_equal(other)
  • smaller_negative: Result = -1 = (Current < other)
  • greater_positive: Result = 1 = (Current > other)

min (other: COMPARABLE): COMPARABLE

Minimum of Current and other.

See also max, in_range.

require

  • other /= Void

ensure

  • Result <= Current and then Result <= other
  • compare(Result) = 0 or else other.compare(Result) = 0

max (other: COMPARABLE): COMPARABLE

Maximum of Current and other.

See also min, in_range.

require

  • other /= Void

ensure

  • Result >= Current and then Result >= other
  • compare(Result) = 0 or else other.compare(Result) = 0