catch executes its block. If throw is not called, the block executes normally, and catch returns the value of the last expression evaluated.
catch(1) { 123 } # => 123
If throw(tag2, val) is called, Ruby searches up its stack for a catch block whose tag has the same object_id as tag2. When found, the block stops executing and returns val (or nil if no second argument was given to throw).
catch(1) { throw(1, 456) } # => 456 catch(1) { throw(1) } # => nil
When tag is passed as the first argument, catch yields it as the parameter of the block.
catch(1) {|x| x + 2 } # => 3
When no tag is given, catch yields a new unique object (as from Object.new) as the block parameter. This object can then be used as the argument to throw, and will match the correct catch block.
catch do |obj_A| catch do |obj_B| throw(obj_B, 123) puts "This puts is not reached" end puts "This puts is displayed" 456 end # => 456 catch do |obj_A| catch do |obj_B| throw(obj_A, 123) puts "This puts is still not reached" end puts "Now this puts is also not reached" 456 end # => 123
Returns a hash containing the counts of equal elements:
Each key is an element of self.
Each value is the number elements equal to that key.
With no argument:
%w[a b c b c a c b].tally # => {"a"=>2, "b"=>3, "c"=>3}
With a hash argument, that hash is used for the tally (instead of a new hash), and is returned; this may be useful for accumulating tallies across multiple enumerables:
hash = {} hash = %w[a c d b c a].tally(hash) hash # => {"a"=>2, "c"=>2, "d"=>1, "b"=>1} hash = %w[b a z].tally(hash) hash # => {"a"=>3, "c"=>2, "d"=>1, "b"=>2, "z"=>1} hash = %w[b a m].tally(hash) hash # => {"a"=>4, "c"=>2, "d"=>1, "b"=>3, "z"=>1, "m"=> 1}
For non-negative integer n, returns the first n elements:
r = (1..4) r.take(2) # => [1, 2] r.take(0) # => [] h = {foo: 0, bar: 1, baz: 2, bat: 3} h.take(2) # => [[:foo, 0], [:bar, 1]]
Returns a list of the supported category symbols.
Enables the coverage measurement. See the documentation of Coverage class in detail. This is equivalent to Coverage.setup and Coverage.resume.
Returns a String containing the generated JSON data.
See also JSON.fast_generate, JSON.pretty_generate.
Argument obj is the Ruby object to be converted to JSON.
Argument opts, if given, contains a Hash of options for the generation. See Generating Options.
When obj is an Array, returns a String containing a JSON array:
obj = ["foo", 1.0, true, false, nil] json = JSON.generate(obj) json # => '["foo",1.0,true,false,null]'
When obj is a Hash, returns a String containing a JSON object:
obj = {foo: 0, bar: 's', baz: :bat} json = JSON.generate(obj) json # => '{"foo":0,"bar":"s","baz":"bat"}'
For examples of generating from other Ruby objects, see Generating JSON from Other Objects.
Raises an exception if any formatting option is not a String.
Raises an exception if obj contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises JSON::NestingError (nesting of 100 is too deep): JSON.generate(a)
Compresses the given string. Valid values of level are Zlib::NO_COMPRESSION, Zlib::BEST_SPEED, Zlib::BEST_COMPRESSION, Zlib::DEFAULT_COMPRESSION, or an integer from 0 to 9.
This method is almost equivalent to the following code:
def deflate(string, level) z = Zlib::Deflate.new(level) dst = z.deflate(string, Zlib::FINISH) z.close dst end
See also Zlib.inflate
Decompresses string. Raises a Zlib::NeedDict exception if a preset dictionary is needed for decompression.
This method is almost equivalent to the following code:
def inflate(string) zstream = Zlib::Inflate.new buf = zstream.inflate(string) zstream.finish zstream.close buf end
See also Zlib.deflate
Returns true if the named file is readable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the effective user/group.
Returns true if the named file is writable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the effective user/group.
Returns true if the named file is executable by the effective user and group id of this process. See eaccess(3).
Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.
Note that some OS-level security features may cause this to return true even though the file is not executable by the effective user/group.
Initiates garbage collection, even if manually disabled.
The full_mark keyword argument determines whether or not to perform a major garbage collection cycle. When set to true, a major garbage collection cycle is ran, meaning all objects are marked. When set to false, a minor garbage collection cycle is ran, meaning only young objects are marked.
The immediate_mark keyword argument determines whether or not to perform incremental marking. When set to true, marking is completed during the call to this method. When set to false, marking is performed in steps that is interleaved with future Ruby code execution, so marking might not be completed during this method call. Note that if full_mark is false then marking will always be immediate, regardless of the value of immediate_mark.
The immediate_sweep keyword argument determines whether or not to defer sweeping (using lazy sweep). When set to false, sweeping is performed in steps that is interleaved with future Ruby code execution, so sweeping might not be completed during this method call. When set to true, sweeping is completed during the call to this method.
Note: These keyword arguments are implementation and version dependent. They are not guaranteed to be future-compatible, and may be ignored if the underlying implementation does not support them.
The standard configuration object for gems.
Use the given configuration object (which implements the ConfigFile protocol) as the standard configuration object.
A Zlib::Deflate.deflate wrapper
Retrieve the PathSupport object that RubyGems uses to lookup files.
Initialize the filesystem paths to use from env. env is a hash-like object (typically ENV) that is queried for ‘GEM_HOME’, ‘GEM_PATH’, and ‘GEM_SPEC_CACHE’ Keys for the env hash should be Strings, and values of the hash should be Strings or nil.
Top level install helper method. Allows you to install gems interactively:
% irb >> Gem.install "minitest" Fetching: minitest-5.14.0.gem (100%) => [#<Gem::Specification:0x1013b4528 @name="minitest", ...>]
Set array of platforms this RubyGems supports (primarily for testing).
Array of platforms this RubyGems supports.
Returns the currently set formatter. By default, it is set to DidYouMean::Formatter.
Updates the primary formatter used to format the suggestions.