Calls block once for each element in self, passing that element as a parameter, converting multiple values from yield to an array.
If no block is given, an enumerator is returned instead.
class Foo include Enumerable def each yield 1 yield 1, 2 yield end end Foo.new.each_entry{ |o| p o }
produces:
1 [1, 2] nil
Iterates the given block for each slice of <n> elements. If no block is given, returns an enumerator.
(1..10).each_slice(3) { |a| p a } # outputs below [1, 2, 3] [4, 5, 6] [7, 8, 9] [10]
Iterates the given block for each array of consecutive <n> elements. If no block is given, returns an enumerator.
e.g.:
(1..10).each_cons(3) { |a| p a } # outputs below [1, 2, 3] [2, 3, 4] [3, 4, 5] [4, 5, 6] [5, 6, 7] [6, 7, 8] [7, 8, 9] [8, 9, 10]
Creates an enumerator for each chunked elements. The beginnings of chunks are defined by the block.
This method split each chunk using adjacent elements, elt_before and elt_after, in the receiver enumerator. This method split chunks between elt_before and elt_after where the block returns false.
The block is called the length of the receiver enumerator minus one.
The result enumerator yields the chunked elements as an array. So each method can be called as follows:
enum.chunk_while { |elt_before, elt_after| bool }.each { |ary| ... }
Other methods of the Enumerator class and Enumerable module, such as to_a, map, etc., are also usable.
For example, one-by-one increasing subsequence can be chunked as follows:
a = [1,2,4,9,10,11,12,15,16,19,20,21] b = a.chunk_while {|i, j| i+1 == j } p b.to_a #=> [[1, 2], [4], [9, 10, 11, 12], [15, 16], [19, 20, 21]] c = b.map {|a| a.length < 3 ? a : "#{a.first}-#{a.last}" } p c #=> [[1, 2], [4], "9-12", [15, 16], "19-21"] d = c.join(",") p d #=> "1,2,4,9-12,15,16,19-21"
Increasing (non-decreasing) subsequence can be chunked as follows:
a = [0, 9, 2, 2, 3, 2, 7, 5, 9, 5] p a.chunk_while {|i, j| i <= j }.to_a #=> [[0, 9], [2, 2, 3], [2, 7], [5, 9], [5]]
Adjacent evens and odds can be chunked as follows: (Enumerable#chunk is another way to do it.)
a = [7, 5, 9, 2, 0, 7, 9, 4, 2, 0] p a.chunk_while {|i, j| i.even? == j.even? }.to_a #=> [[7, 5, 9], [2, 0], [7, 9], [4, 2, 0]]
Enumerable#slice_when does the same, except splitting when the block returns true instead of false.
Generate a JSON document from the Ruby data structure obj and return it. This method disables the checks for circles in Ruby objects.
WARNING: Be careful not to pass any Ruby data structures with circles as obj argument because this will cause JSON to go into an infinite loop.
Generate a JSON document from the Ruby data structure obj and return it. The returned document is a prettier form of the document returned by unparse.
The opts argument can be used to configure the generator. See the generate method for a more detailed explanation.
Returns the source file origin from the given object.
See ::trace_object_allocations for more information and examples.
Returns the original line from source for from the given object.
See ::trace_object_allocations for more information and examples.
Calls the block once for each living, nonimmediate object in this Ruby process. If module is specified, calls the block for only those classes or modules that match (or are a subclass of) module. Returns the number of objects found. Immediate objects (Fixnums, Symbols true, false, and nil) are never returned. In the example below, each_object returns both the numbers we defined and several constants defined in the Math module.
If no block is given, an enumerator is returned instead.
a = 102.7 b = 95 # Won't be returned c = 12345678987654321 count = ObjectSpace.each_object(Numeric) {|x| p x } puts "Total count: #{count}"
produces:
12345678987654321 102.7 2.71828182845905 3.14159265358979 2.22044604925031e-16 1.7976931348623157e+308 2.2250738585072e-308 Total count: 7
Takes a hash as its argument. The key is a symbol or an array of symbols. These symbols correspond to method names. The value is the accessor to which the methods will be delegated.
Takes a hash as its argument. The key is a symbol or an array of symbols. These symbols correspond to method names. The value is the accessor to which the methods will be delegated.
Returns whether or not macro is defined either in the common header files or within any headers you provide.
Any options you pass to opt are passed along to the compiler.
Returns the size of the given type. You may optionally specify additional headers to search in for the type.
If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with SIZEOF_, followed by the type name, followed by =X where “X” is the actual size.
For example, if check_sizeof('mystruct') returned 12, then the SIZEOF_MYSTRUCT=12 preprocessor macro would be passed to the compiler.
Returns the signedness of the given type. You may optionally specify additional headers to search in for the type.
If the type is found and is a numeric type, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with SIGNEDNESS_OF_, followed by the type name, followed by =X where “X” is positive integer if the type is unsigned and a negative integer if the type is signed.
For example, if size_t is defined as unsigned, then check_signedness('size_t') would return +1 and the SIGNEDNESS_OF_SIZE_T=+1 preprocessor macro would be passed to the compiler. The SIGNEDNESS_OF_INT=-1 macro would be set for check_signedness('int')
Generates a header file consisting of the various macro definitions generated by other methods such as have_func and have_header. These are then wrapped in a custom #ifndef based on the header file name, which defaults to “extconf.h”.
For example:
# extconf.rb require 'mkmf' have_func('realpath') have_header('sys/utime.h') create_header create_makefile('foo')
The above script would generate the following extconf.h file:
#ifndef EXTCONF_H #define EXTCONF_H #define HAVE_REALPATH 1 #define HAVE_SYS_UTIME_H 1 #endif
Given that the create_header method generates a file based on definitions set earlier in your extconf.rb file, you will probably want to make this one of the last methods you call in your script.
creates a stub Makefile.
Enters exclusive section and executes the block. Leaves the exclusive section automatically when the block exits. See example under MonitorMixin.
See Mutex#synchronize
Returns a Hash of the defined schemes
Try to activate a gem containing path. Returns true if activation succeeded or wasn’t needed because it was already activated. Returns false if it can’t find the path in a gem.