diff options
author | charliesome <charliesome@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-06-30 13:40:10 +0000 |
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committer | charliesome <charliesome@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-06-30 13:40:10 +0000 |
commit | 3628ab809279e062c5aa75384ecd31364fec0455 (patch) | |
tree | 62a3c83b62a87e5f140f7ac1c4762bfc6a1fb2fe /lib/prime.rb | |
parent | 305f06c7e353db5f4e9310121d2d36fc85d1b461 (diff) | |
download | ruby-3628ab809279e062c5aa75384ecd31364fec0455.tar.gz |
* lib/prime.rb: Corrected a few comments. Patch by @Nullset14.
Fixes GH-346.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41714 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'lib/prime.rb')
-rw-r--r-- | lib/prime.rb | 36 |
1 files changed, 18 insertions, 18 deletions
diff --git a/lib/prime.rb b/lib/prime.rb index 7abcbebb0f..1face45338 100644 --- a/lib/prime.rb +++ b/lib/prime.rb @@ -71,20 +71,20 @@ end # # A "generator" provides an implementation of enumerating pseudo-prime # numbers and it remembers the position of enumeration and upper bound. -# Furthermore, it is a external iterator of prime enumeration which is -# compatible to an Enumerator. +# Furthermore, it is an external iterator of prime enumeration which is +# compatible with an Enumerator. # # +Prime+::+PseudoPrimeGenerator+ is the base class for generators. # There are few implementations of generator. # # [+Prime+::+EratosthenesGenerator+] -# Uses eratosthenes's sieve. +# Uses eratosthenes' sieve. # [+Prime+::+TrialDivisionGenerator+] # Uses the trial division method. # [+Prime+::+Generator23+] -# Generates all positive integers which is not divided by 2 nor 3. +# Generates all positive integers which are not divisible by either 2 or 3. # This sequence is very bad as a pseudo-prime sequence. But this -# is faster and uses much less memory than other generators. So, +# is faster and uses much less memory than the other generators. So, # it is suitable for factorizing an integer which is not large but # has many prime factors. e.g. for Prime#prime? . @@ -133,13 +133,13 @@ class Prime # a parameter. # # +ubound+:: - # Upper bound of prime numbers. The iterator stops after + # Upper bound of prime numbers. The iterator stops after it # yields all prime numbers p <= +ubound+. # # == Note # - # +Prime+.+new+ returns a object extended by +Prime+::+OldCompatibility+ - # in order to compatibility to Ruby 1.8, and +Prime+#each is overwritten + # +Prime+.+new+ returns an object extended by +Prime+::+OldCompatibility+ + # in order to be compatible with Ruby 1.8, and +Prime+#each is overwritten # by +Prime+::+OldCompatibility+#+each+. # # +Prime+.+new+ is now obsolete. Use +Prime+.+instance+.+each+ or simply @@ -191,9 +191,9 @@ class Prime # +value+:: An arbitrary integer. # +generator+:: Optional. A pseudo-prime generator. # +generator+.succ must return the next - # pseudo-prime number in the ascendent + # pseudo-prime number in the ascending # order. It must generate all prime numbers, - # but may generate non prime numbers. + # but may also generate non prime numbers too. # # === Exceptions # +ZeroDivisionError+:: when +value+ is zero. @@ -209,7 +209,7 @@ class Prime # # Prime.prime_division(12) #=> [[2,2], [3,1]] # - def prime_division(value, generator= Prime::Generator23.new) + def prime_division(value, generator = Prime::Generator23.new) raise ZeroDivisionError if value == 0 if value < 0 value = -value @@ -272,7 +272,7 @@ class Prime raise NotImplementedError, "need to define `rewind'" end - # Iterates the given block for each prime numbers. + # Iterates the given block for each prime number. def each(&block) return self.dup unless block if @ubound @@ -336,11 +336,11 @@ class Prime alias next succ end - # Generates all integer which are greater than 2 and - # are not divided by 2 nor 3. + # Generates all integers which are greater than 2 and + # are not divisible by either 2 or 3. # # This is a pseudo-prime generator, suitable on - # checking primality of a integer by brute force + # checking primality of an integer by brute force # method. class Generator23<PseudoPrimeGenerator def initialize @@ -418,7 +418,7 @@ class Prime end end - # Internal use. An implementation of eratosthenes's sieve + # Internal use. An implementation of eratosthenes' sieve class EratosthenesSieve include Singleton @@ -456,7 +456,7 @@ class Prime end private - # for an odd number +n+, returns (i, j, k) such that @tables[i][j][k] represents primarity of the number + # for an odd number +n+, returns (i, j, k) such that @tables[i][j][k] represents primality of the number def indices(n) # binary digits of n: |0|1|2|3|4|5|6|7|8|9|10|11|.... # indices: |-| k | j | i @@ -471,7 +471,7 @@ class Prime def extend_table lbound = NUMS_PER_TABLE * @tables.length ubound = lbound + NUMS_PER_TABLE - new_table = [FILLED_ENTRY] * ENTRIES_PER_TABLE # which represents primarity in lbound...ubound + new_table = [FILLED_ENTRY] * ENTRIES_PER_TABLE # which represents primality in lbound...ubound (3..Integer(Math.sqrt(ubound))).step(2) do |p| i, j, k = indices(p) next if @tables[i][j][k].zero? |