Calls say with msg or the results of the block if really_verbose is true.
Is code an error status?
Is code an error status?
Returns the effective group ID for this process. Not available on all platforms.
Process.egid #=> 500
Sets the curve parameters. generator must be an instance of EC::Point that is on the curve. order and cofactor are integers.
See the OpenSSL documentation for EC_GROUP_set_generator()
Tries to convert obj into an array, using to_ary method. Returns the converted array or nil if obj cannot be converted for any reason. This method can be used to check if an argument is an array.
Array.try_convert([1]) #=> [1] Array.try_convert("1") #=> nil if tmp = Array.try_convert(arg) # the argument is an array elsif tmp = String.try_convert(arg) # the argument is a string end
Same as Array#each, but traverses self in reverse order.
a = [ "a", "b", "c" ] a.reverse_each {|x| print x, " " }
produces:
c b a
When invoked with a block, yield all repeated permutations of length n of the elements of the array, then return the array itself.
The implementation makes no guarantees about the order in which the repeated permutations are yielded.
If no block is given, an Enumerator is returned instead.
Examples:
a = [1, 2] a.repeated_permutation(1).to_a #=> [[1], [2]] a.repeated_permutation(2).to_a #=> [[1,1],[1,2],[2,1],[2,2]] a.repeated_permutation(3).to_a #=> [[1,1,1],[1,1,2],[1,2,1],[1,2,2], # [2,1,1],[2,1,2],[2,2,1],[2,2,2]] a.repeated_permutation(0).to_a #=> [[]] # one permutation of length 0
Scans the current string until the match is exhausted yielding each match as it is encountered in the string. A block is not necessary as the results will simply be aggregated into the final array.
"123 456".block_scanf("%d") # => [123, 456]
If a block is given, the value from that is returned from the yield is added to an output array.
"123 456".block_scanf("%d) do |digit,| # the ',' unpacks the Array
digit + 100
end
# => [223, 556]
See Scanf for details on creating a format string.
You will need to require ‘scanf’ to use String#block_scanf
Try to convert obj into a String, using to_str method. Returns converted string or nil if obj cannot be converted for any reason.
String.try_convert("str") #=> "str" String.try_convert(/re/) #=> nil
Returns the next representable floating-point number.
Float::MAX.next_float and Float::INFINITY.next_float is Float::INFINITY.
Float::NAN.next_float is Float::NAN.
For example:
p 0.01.next_float #=> 0.010000000000000002 p 1.0.next_float #=> 1.0000000000000002 p 100.0.next_float #=> 100.00000000000001 p 0.01.next_float - 0.01 #=> 1.734723475976807e-18 p 1.0.next_float - 1.0 #=> 2.220446049250313e-16 p 100.0.next_float - 100.0 #=> 1.4210854715202004e-14 f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.next_float } #=> 0x1.47ae147ae147bp-7 0.01 # 0x1.47ae147ae147cp-7 0.010000000000000002 # 0x1.47ae147ae147dp-7 0.010000000000000004 # 0x1.47ae147ae147ep-7 0.010000000000000005 # 0x1.47ae147ae147fp-7 0.010000000000000007 # 0x1.47ae147ae148p-7 0.010000000000000009 # 0x1.47ae147ae1481p-7 0.01000000000000001 # 0x1.47ae147ae1482p-7 0.010000000000000012 # 0x1.47ae147ae1483p-7 0.010000000000000014 # 0x1.47ae147ae1484p-7 0.010000000000000016 # 0x1.47ae147ae1485p-7 0.010000000000000018 # 0x1.47ae147ae1486p-7 0.01000000000000002 # 0x1.47ae147ae1487p-7 0.010000000000000021 # 0x1.47ae147ae1488p-7 0.010000000000000023 # 0x1.47ae147ae1489p-7 0.010000000000000024 # 0x1.47ae147ae148ap-7 0.010000000000000026 # 0x1.47ae147ae148bp-7 0.010000000000000028 # 0x1.47ae147ae148cp-7 0.01000000000000003 # 0x1.47ae147ae148dp-7 0.010000000000000031 # 0x1.47ae147ae148ep-7 0.010000000000000033 f = 0.0 100.times { f += 0.1 } p f #=> 9.99999999999998 # should be 10.0 in the ideal world. p 10-f #=> 1.9539925233402755e-14 # the floating-point error. p(10.0.next_float-10) #=> 1.7763568394002505e-15 # 1 ulp (units in the last place). p((10-f)/(10.0.next_float-10)) #=> 11.0 # the error is 11 ulp. p((10-f)/(10*Float::EPSILON)) #=> 8.8 # approximation of the above. p "%a" % f #=> "0x1.3fffffffffff5p+3" # the last hex digit is 5. 16 - 5 = 11 ulp.
Returns the previous representable floating-point number.
(-Float::MAX).prev_float and (-Float::INFINITY).prev_float is -Float::INFINITY.
Float::NAN.prev_float is Float::NAN.
For example:
p 0.01.prev_float #=> 0.009999999999999998 p 1.0.prev_float #=> 0.9999999999999999 p 100.0.prev_float #=> 99.99999999999999 p 0.01 - 0.01.prev_float #=> 1.734723475976807e-18 p 1.0 - 1.0.prev_float #=> 1.1102230246251565e-16 p 100.0 - 100.0.prev_float #=> 1.4210854715202004e-14 f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.prev_float } #=> 0x1.47ae147ae147bp-7 0.01 # 0x1.47ae147ae147ap-7 0.009999999999999998 # 0x1.47ae147ae1479p-7 0.009999999999999997 # 0x1.47ae147ae1478p-7 0.009999999999999995 # 0x1.47ae147ae1477p-7 0.009999999999999993 # 0x1.47ae147ae1476p-7 0.009999999999999992 # 0x1.47ae147ae1475p-7 0.00999999999999999 # 0x1.47ae147ae1474p-7 0.009999999999999988 # 0x1.47ae147ae1473p-7 0.009999999999999986 # 0x1.47ae147ae1472p-7 0.009999999999999985 # 0x1.47ae147ae1471p-7 0.009999999999999983 # 0x1.47ae147ae147p-7 0.009999999999999981 # 0x1.47ae147ae146fp-7 0.00999999999999998 # 0x1.47ae147ae146ep-7 0.009999999999999978 # 0x1.47ae147ae146dp-7 0.009999999999999976 # 0x1.47ae147ae146cp-7 0.009999999999999974 # 0x1.47ae147ae146bp-7 0.009999999999999972 # 0x1.47ae147ae146ap-7 0.00999999999999997 # 0x1.47ae147ae1469p-7 0.009999999999999969 # 0x1.47ae147ae1468p-7 0.009999999999999967
Returns default external encoding.
The default external encoding is used by default for strings created from the following locations:
File data read from disk
While strings created from these locations will have this encoding, the encoding may not be valid. Be sure to check String#valid_encoding?.
File data written to disk will be transcoded to the default external encoding when written.
The default external encoding is initialized by the locale or -E option.
Sets default external encoding. You should not set Encoding::default_external in ruby code as strings created before changing the value may have a different encoding from strings created after the value was changed., instead you should use ruby -E to invoke ruby with the correct default_external.
See Encoding::default_external for information on how the default external encoding is used.