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Negative numbers can't be primes by definition. #187

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Negative numbers can't be primes by definition. #187

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1 change: 0 additions & 1 deletion lib/prime.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,6 @@ def each(ubound = nil, generator = EratosthenesGenerator.new, &block)
# +value+:: an arbitrary integer to be checked.
# +generator+:: optional. A pseudo-prime generator.
def prime?(value, generator = Prime::Generator23.new)
value = -value if value < 0
return false if value < 2
for num in generator
q,r = value.divmod num
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4 changes: 2 additions & 2 deletions test/test_prime.rb
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Expand Up @@ -141,8 +141,8 @@ def test_prime?

# negative
assert !-1.prime?
assert(-2.prime?)
assert(-3.prime?)
assert !-2.prime?
assert !-3.prime?
assert !-4.prime?
end
end
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