[ Home Page ] [ Eiffel Archive ] [ Eiffel Classes and Clusters ]

Factorial Based (FB) Numbers v0.2

Written by Nicolas Waquier (nicolas@esclare.fdn.org)

• 22 November 1994.
• Targets TowerEiffel 1.3.1
• The main class is "eencoded" (no source code)

factorial-0.2.tar.gz (13,225 bytes)

Licensing

• You can use/modify it for your own use, but not redistribute your modifications as a library/class/cluster.
• No restriction about executables.

Status

• Will be enhanced.
• One class is eencoded.
• Please report every problem.

Contents

FACTORIAL

the BIG INTEGER class

F_TEST

to test the cluster

Target Use

Where common numbers (integers, real, double) are not appropriate. For big numbers.

Future Plans

• add the missing features (*, /).
• make it interoperate with different compilers.
• add a class with real factorial
• add a class with fractional factorial
• add a class with math functions (as in DOUBLE_MATH) - for that, I need help.
• add a class to join integer with factorial
• add a limit to the size of numbers, when they lose significance.

Requirements

Compiler

Tower Eiffel 1.3.1.0

Clusters

Kernel

Time to compile

11 sec Eiffel -> C

Development platform

• nextstep/486

Short Form

indexing         calculus, precision;         names: fb, big_integers;         size: dynamic;         class interface FACTORIAL ancestors         FACTORIAL                 COMPARABLE_NUMERIC                         COMPARABLE                                 PART_COMPARABLE                         NUMERIC feature summary         infix "*" (other : like Current) : like Current         infix "+" (other : like Current) : like Current         prefix "+" : like Current         infix "-" (other : like Current) : like Current         prefix "-" : like Current         infix "/" (other : like Current) : like Current         infix "<" (other : like Current) : BOOLEAN         infix "<=" (other : like Current) : BOOLEAN         infix ">" (other : like Current) : BOOLEAN         infix ">=" (other : like Current) : BOOLEAN         infix "^" (exp : INTEGER) : like Current         abs : like Current         compare (other : like Current) : INTEGER         copy (other : like Current)         from_integer (i : INTEGER)         gcd (other : like Current) : like Current         greatest_common_divisor (other : like Current) : like Current         integer_representable : BOOLEAN         is_equal (other : like Current) : BOOLEAN         make         manifest (entry : ARRAY [INTEGER])         max (other : like Current) : like Current         min (other : like Current) : like Current         one : FACTORIAL         out : STRING         setup (other : like Current)         sign : INTEGER         to_integer : INTEGER         valid_divisor (other : like Current) : BOOLEAN         zero : FACTORIAL creation         make, from_integer, setup, manifest inherited features         -- From COMPARABLE:         infix "<=", compare, max, min         -- From PART_COMPARABLE:         infix ">", infix ">="         -- From NUMERIC:         prefix "+" feature specification         -- Creation         make                         -- create a new FB number, set it to zero.         setup (other : like Current)                         -- create a new FB number regarding other.         manifest (entry : ARRAY [INTEGER])                         -- create a new FB number from a manifest-array of integers.         from_integer (i : INTEGER)                         -- create a new FB number from integer i. feature specification         -- info         is_equal (other : like Current) : BOOLEAN                         -- compare other with Current.                 require                         other_not_void : other /= void;         out : STRING                         -- New string containing a printable representation of Current.         sign : INTEGER                         -- the sign of Current.                 ensure                         negative_condition : (Result = (- 1)) = (Current < zero);                         zero_condition : (Result = 0) = (not ((Current < zero) or (Current > zero)));                         positive_condition : (Result = 1) = (Current > zero);         integer_representable : BOOLEAN         to_integer : INTEGER                         -- conversion of Current to an integer.                 require                         not_too_big : integer_representable; feature specification         -- related factorial based numbers         one : FACTORIAL                         -- '1'         zero : FACTORIAL                         -- '0'         abs : like Current                         -- the absolute value of Current                 ensure                         same_as_negative : (Current < zero) = (compare (- Result) = 0);                         same_if_positive : (Current >= zero) = (compare (Result) = 0);         gcd,         greatest_common_divisor (other : like Current) : like Current                         -- the GCD between Current and other. feature specification         -- comparison         infix "<" (other : like Current) : BOOLEAN                         -- Is Current less than other?                 require                         other /= void                 ensure                         other_not_less_or_equal : Result = (not (other <= Current));                         consistent : Result implies (not (other <= Current));                         not_reflexive : (Current = other) implies (not Result);                         other_not_less_or_equal : Result = (not (other <= Current));                         consistent : Result implies (not (other <= Current));                         not_reflexive : (Current = other) implies (not Result); feature specification         -- operations         infix "+" (other : like Current) : like Current                         -- Sum of Current and other                 require                         other /= void         infix "-" (other : like Current) : like Current                         -- Difference between Current  and other                 require                         other /= void         prefix "-" : like Current                         -- Unary subtraction applied to Current         infix "*" (other : like Current) : like Current                         -- multiplication                 require                         other_not_void : other /= void;         infix "/" (other : like Current) : like Current                         -- division                         -- not implemented                 require                         other_not_void : other /= void;                         valid_divisor : valid_divisor (other);         infix "^" (exp : INTEGER) : like Current                         -- not implemented                 require                         non_negative_exponent : exp >= 0; feature specification         -- other         valid_divisor (other : like Current) : BOOLEAN                         -- not implemented                 require                         other_not_void : other /= void;         copy (other : like Current)                         -- set Current a copy of other                 require                         other_not_void : other /= void;                         conformance : other.conforms_to (Current);                 ensure                         result_is_equal : is_equal (other); end interface -- class FACTORIAL

[ Home Page ] [ Eiffel Archive ] [ Eiffel Classes and Clusters ]