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Compatible Doclog docs for library(arithmetic) and small fixes on INDEX.md

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This commit is contained in:
Adrián Arroyo Calle
2023-01-25 19:48:01 +01:00
parent 82dd9e0596
commit 6d99912b7b
2 changed files with 35 additions and 7 deletions
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26
src/lib/arithmetic.pl
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@@ -1,3 +1,8 @@
/** Arithmetic predicates
These predicates are additions to standard the arithmetic functions provided by `is/2`.
*/
:- module(arithmetic, [expmod/4, lcm/3, lsb/2, msb/2, number_to_rational/2,
number_to_rational/3, popcount/2,
rational_numerator_denominator/3]).
@@ -6,6 +11,10 @@
:- use_module(library(error)).
:- use_module(library(lists), [append/3, member/2]).
%% expmod(+Base, +Expo, +Mod, -R).
%
% Modular exponentiation. Base, Expo and Mod must be integers.
expmod(Base, Expo, Mod, R) :-
( member(N, [Base, Expo, Mod]), var(N) -> instantiation_error(expmod/4)
; member(N, [Base, Expo, Mod]), \+ integer(N) ->
@@ -44,6 +53,9 @@ lcm(A, B, X) :-
X is abs(B) // gcd(A,B) * abs(A)
).
%% lsb(+X, -N).
%
% True iff N is the least significat bit of integer X
lsb(X, N) :-
builtins:must_be_number(X, lsb/2),
( \+ integer(X) -> type_error(integer, X, lsb/2)
@@ -53,6 +65,9 @@ lsb(X, N) :-
msb_(X1, -1, N)
).
%% msb(+X, -N).
%
% True iff N is the most significant bit of integer X
msb(X, N) :-
builtins:must_be_number(X, msb/2),
( \+ integer(X) -> type_error(integer, X, msb/2)
@@ -68,6 +83,9 @@ msb_(X, M, N) :-
M1 is M + 1,
msb_(X1, M1, N).
%% number_to_rational(+Real, -Fraction).
%
% True iff given a number Real, Fraction is the same number represented as a fraction.
number_to_rational(Real, Fraction) :-
( var(Real) -> instantiation_error(number_to_rational/2)
; integer(Real) -> Fraction is Real rdiv 1
@@ -126,12 +144,20 @@ simplify_fraction(A0/B0, A/B) :-
A is A0 // G,
B is B0 // G.
%% rational_numerator_denominator(+Fraction, -Numerator, -Denominator).
%
% True iff given a fraction Fraction, Numerator is the numerator of that fraction
% and Denominator the denominator.
rational_numerator_denominator(R, N, D) :-
write_term_to_chars(R, [], Cs),
append(Ns, [' ', r, d, i, v, ' '|Ds], Cs),
number_chars(N, Ns),
number_chars(D, Ds).
%% popcount(+Number, -Bits1).
%
% True iff given an integer Number, Bits1 is the amount of 1 bits the binary representation
% of that number has.
popcount(X, N) :-
must_be(integer, X),
'$popcount'(X, N).