Returns the value as a rational. The optional argument eps is always ignored.
Returns a new set that is a copy of the set, flattening each containing set recursively.
Equivalent to Set#flatten, but replaces the receiver with the result in place. Returns nil if no modifications were made.
Calls the given block once for each element in the set, passing the element as parameter. Returns an enumerator if no block is given.
Creates a Shell object which current directory is set to path.
If a block is given, it restores the current directory when the block ends.
If called as iterator, it restores the current directory when the block ends.
Returns the full path name of the temporary file. This will be nil if unlink has been called.
Creates a temporary file as usual File object (not Tempfile). It doesn’t use finalizer and delegation.
If no block is given, this is similar to Tempfile.new except creating File instead of Tempfile. The created file is not removed automatically. You should use File.unlink to remove it.
If a block is given, then a File object will be constructed, and the block is invoked with the object as the argument. The File object will be automatically closed and the temporary file is removed after the block terminates. The call returns the value of the block.
In any case, all arguments (+*args+) will be treated as Tempfile.new.
Tempfile.create('foo', '/home/temp') do |f|
... do something with f ...
end
Returns the main thread.
Terminates thr and schedules another thread to be run.
If this thread is already marked to be killed, exit returns the Thread.
If this is the main thread, or the last thread, exits the process.
Returns the status of thr.
"sleep"
Returned if this thread is sleeping or waiting on I/O
"run"
When this thread is executing
"aborting"
If this thread is aborting
false
When this thread is terminated normally
nil
If terminated with an exception.
a = Thread.new { raise("die now") } b = Thread.new { Thread.stop } c = Thread.new { Thread.exit } d = Thread.new { sleep } d.kill #=> #<Thread:0x401b3678 aborting> a.status #=> nil b.status #=> "sleep" c.status #=> false d.status #=> "aborting" Thread.current.status #=> "run"
Path of the file being run
Returns internal information of TracePoint.
The contents of the returned value are implementation specific. It may be changed in future.
This method is only for debugging TracePoint itself.
See also BigDecimal.new
Creates a new Pathname object from the given string, path, and returns pathname object.
In order to use this constructor, you must first require the Pathname standard library extension.
require 'pathname' Pathname("/home/zzak") #=> #<Pathname:/home/zzak>
See also Pathname::new for more information.
Equivalent to:
$stdout.putc(int)
Refer to the documentation for IO#putc for important information regarding multi-byte characters.
Returns arg converted to a float. Numeric types are converted directly, and with exception to string and nil the rest are converted using arg.to_f. Converting a string with invalid characters will result in a ArgumentError. Converting nil generates a TypeError.
Float(1) #=> 1.0 Float("123.456") #=> 123.456 Float("123.0_badstring") #=> ArgumentError: invalid value for Float(): "123.0_badstring" Float(nil) #=> TypeError: can't convert nil into Float
Returns x/y;
Rational(1, 2) #=> (1/2) Rational('1/2') #=> (1/2) Rational(nil) #=> TypeError Rational(1, nil) #=> TypeError
Syntax of string form:
string form = extra spaces , rational , extra spaces ;
rational = [ sign ] , unsigned rational ;
unsigned rational = numerator | numerator , "/" , denominator ;
numerator = integer part | fractional part | integer part , fractional part ;
denominator = digits ;
integer part = digits ;
fractional part = "." , digits , [ ( "e" | "E" ) , [ sign ] , digits ] ;
sign = "-" | "+" ;
digits = digit , { digit | "_" , digit } ;
digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
extra spaces = ? \s* ? ;
See String#to_r.
Equivalent to ($_.dup).chop!, except nil is never returned. See String#chop!. Available only when -p/-n command line option specified.
Equivalent to $_ = $_.chomp(string). See String#chomp. Available only when -p/-n command line option specified.
Returns true if yield would execute a block in the current context. The iterator? form is mildly deprecated.
def try if block_given? yield else "no block" end end try #=> "no block" try { "hello" } #=> "hello" try do "hello" end #=> "hello"
Returns a new array with the results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.
(1..4).map { |i| i*i } #=> [1, 4, 9, 16] (1..4).collect { "cat" } #=> ["cat", "cat", "cat", "cat"]
Returns the object in enum with the maximum value. The first form assumes all objects implement Comparable; the second uses the block to return a <=> b.
a = %w(albatross dog horse) a.max #=> "horse" a.max { |a, b| a.length <=> b.length } #=> "albatross"
If the n argument is given, maximum n elements are returned as an array, sorted in descending order.
a = %w[albatross dog horse] a.max(2) #=> ["horse", "dog"] a.max(2) {|a, b| a.length <=> b.length } #=> ["albatross", "horse"] [5, 1, 3, 4, 2].max(3) #=> [5, 4, 3]
Enumerates over the items, chunking them together based on the return value of the block.
Consecutive elements which return the same block value are chunked together.
For example, consecutive even numbers and odd numbers can be chunked as follows.
[3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5].chunk { |n| n.even? }.each { |even, ary| p [even, ary] } #=> [false, [3, 1]] # [true, [4]] # [false, [1, 5, 9]] # [true, [2, 6]] # [false, [5, 3, 5]]
This method is especially useful for sorted series of elements. The following example counts words for each initial letter.
open("/usr/share/dict/words", "r:iso-8859-1") { |f| f.chunk { |line| line.ord }.each { |ch, lines| p [ch.chr, lines.length] } } #=> ["\n", 1] # ["A", 1327] # ["B", 1372] # ["C", 1507] # ["D", 791] # ...
The following key values have special meaning:
nil and :_separator specifies that the elements should be dropped.
:_alone specifies that the element should be chunked by itself.
Any other symbols that begin with an underscore will raise an error:
items.chunk { |item| :_underscore } #=> RuntimeError: symbols beginning with an underscore are reserved
nil and :_separator can be used to ignore some elements.
For example, the sequence of hyphens in svn log can be eliminated as follows:
sep = "-"*72 + "\n" IO.popen("svn log README") { |f| f.chunk { |line| line != sep || nil }.each { |_, lines| pp lines } } #=> ["r20018 | knu | 2008-10-29 13:20:42 +0900 (Wed, 29 Oct 2008) | 2 lines\n", # "\n", # "* README, README.ja: Update the portability section.\n", # "\n"] # ["r16725 | knu | 2008-05-31 23:34:23 +0900 (Sat, 31 May 2008) | 2 lines\n", # "\n", # "* README, README.ja: Add a note about default C flags.\n", # "\n"] # ...
Paragraphs separated by empty lines can be parsed as follows:
File.foreach("README").chunk { |line| /\A\s*\z/ !~ line || nil }.each { |_, lines| pp lines }
:_alone can be used to force items into their own chunk. For example, you can put lines that contain a URL by themselves, and chunk the rest of the lines together, like this:
pattern = /http/ open(filename) { |f| f.chunk { |line| line =~ pattern ? :_alone : true }.each { |key, lines| pp lines } }
If no block is given, an enumerator to ‘chunk` is returned instead.
Computes the arctangent of decimal to the specified number of digits of precision, numeric.
If decimal is NaN, returns NaN.
BigMath.atan(BigDecimal.new('-1'), 16).to_s #=> "-0.785398163397448309615660845819878471907514682065e0"