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authordrbrain <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-06-01 00:21:46 +0000
committerdrbrain <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-06-01 00:21:46 +0000
commitb6dd727b86a9107dfb6f00164151fc59d50e8605 (patch)
tree4896bd20d866cefd8751484e251fb7252726cb66 /lib/prime.rb
parentf4273e88a8a6be5bb92aebb8a3fe4cf78829607a (diff)
* lib/prime.rb: Indent examples enough to appear as code sections.
Note that Prime is Enumerable. [#4762] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31880 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'lib/prime.rb')
-rw-r--r--lib/prime.rb50
1 files changed, 32 insertions, 18 deletions
diff --git a/lib/prime.rb b/lib/prime.rb
index d1164dbd05..4a20d93fb7 100644
--- a/lib/prime.rb
+++ b/lib/prime.rb
@@ -46,11 +46,17 @@ end
# The set of all prime numbers.
#
# == Example
-# Prime.each(100) do |prime|
-# p prime #=> 2, 3, 5, 7, 11, ...., 97
-# end
+#
+# Prime.each(100) do |prime|
+# p prime #=> 2, 3, 5, 7, 11, ...., 97
+# end
+#
+# Prime is Enumerable:
+#
+# Prime.first 5 # => [2, 3, 5, 7, 11]
#
# == Retrieving the instance
+#
# +Prime+.new is obsolete. Now +Prime+ has the default instance and you can
# access it as +Prime+.instance.
#
@@ -58,10 +64,11 @@ end
# as a class method of +Prime+.
#
# e.g.
-# Prime.instance.prime?(2) #=> true
-# Prime.prime?(2) #=> true
+# Prime.instance.prime?(2) #=> true
+# Prime.prime?(2) #=> true
#
# == Generators
+#
# A "generator" provides an implementation of enumerating pseudo-prime
# numbers and it remembers the position of enumeration and upper bound.
# Futhermore, it is a external iterator of prime enumeration which is
@@ -80,6 +87,7 @@ end
# is faster and uses much less memory than other generators. So,
# it is suitable for factorizing an integer which is not large but
# has many prime factors. e.g. for Prime#prime? .
+
class Prime
include Enumerable
@the_instance = Prime.new
@@ -105,6 +113,7 @@ class Prime
# Iterates the given block over all prime numbers.
#
# == Parameters
+ #
# +ubound+::
# Optional. An arbitrary positive number.
# The upper bound of enumeration. The method enumerates
@@ -113,11 +122,13 @@ class Prime
# Optional. An implementation of pseudo-prime generator.
#
# == Return value
+ #
# An evaluated value of the given block at the last time.
# Or an enumerator which is compatible to an +Enumerator+
# if no block given.
#
# == Description
+ #
# Calls +block+ once for each prime number, passing the prime as
# a parameter.
#
@@ -126,6 +137,7 @@ class Prime
# 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
# by +Prime+::+OldCompatibility+#+each+.
@@ -141,6 +153,7 @@ class Prime
# Returns true if +value+ is prime, false for a composite.
#
# == Parameters
+ #
# +value+:: an arbitrary integer to be checked.
# +generator+:: optional. A pseudo-prime generator.
def prime?(value, generator = Prime::Generator23.new)
@@ -161,10 +174,11 @@ class Prime
# and a natural number -- an exponent.
#
# == Example
- # For [[p_1, e_1], [p_2, e_2], ...., [p_n, e_n]], it returns
- # p_1**e_1 * p_2**e_2 * .... * p_n**e_n.
+ # For <tt>[[p_1, e_1], [p_2, e_2], ...., [p_n, e_n]]</tt>, it returns:
+ #
+ # p_1**e_1 * p_2**e_2 * .... * p_n**e_n.
#
- # Prime.int_from_prime_division([[2,2], [3,1]]) #=> 12
+ # Prime.int_from_prime_division([[2,2], [3,1]]) #=> 12
def int_from_prime_division(pd)
pd.inject(1){|value, (prime, index)|
value *= prime**index
@@ -185,12 +199,15 @@ class Prime
# +ZeroDivisionError+:: when +value+ is zero.
#
# == Example
- # For an arbitrary integer
- # n = p_1**e_1 * p_2**e_2 * .... * p_n**e_n,
- # prime_division(n) returns
- # [[p_1, e_1], [p_2, e_2], ...., [p_n, e_n]].
+ # For an arbitrary integer:
+ #
+ # n = p_1**e_1 * p_2**e_2 * .... * p_n**e_n,
+ #
+ # prime_division(n) returns:
#
- # Prime.prime_division(12) #=> [[2,2], [3,1]]
+ # [[p_1, e_1], [p_2, e_2], ...., [p_n, e_n]].
+ #
+ # Prime.prime_division(12) #=> [[2,2], [3,1]]
#
def prime_division(value, generator= Prime::Generator23.new)
raise ZeroDivisionError if value == 0
@@ -353,9 +370,6 @@ class Prime
end
end
-
-
-
# Internal use. An implementation of prime table by trial division method.
class TrialDivision
include Singleton
@@ -483,8 +497,8 @@ class Prime
# Overwrites Prime#each.
#
- # Iterates the given block over all prime numbers. Note that enumeration starts from
- # the current position of internal pointer, not rewound.
+ # Iterates the given block over all prime numbers. Note that enumeration
+ # starts from the current position of internal pointer, not rewound.
def each(&block)
return @generator.dup unless block_given?
loop do