Returns the usable width for out
. As the width of out
:
If out
is assigned to a tty device, its width is used.
Otherwise, or it could not get the value, the COLUMN
environment variable is assumed to be set to the width.
If COLUMN
is not set to a non-zero number, 80 is assumed.
And finally, returns the above width value - 1.
This -1 is for Windows command prompt, which moves the cursor to the next line if it reaches the last column.
Returns match and captures at the given indexes
, which may include any mixture of:
Integers.
Ranges.
Names (strings and symbols).
Examples:
m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m.values_at(0, 2, -2) # => ["HX1138", "X", "113"] m.values_at(1..2, -1) # => ["H", "X", "8"] m = /(?<a>\d+) *(?<op>[+\-*\/]) *(?<b>\d+)/.match("1 + 2") # => #<MatchData "1 + 2" a:"1" op:"+" b:"2"> m.values_at(0, 1..2, :a, :b, :op) # => ["1 + 2", "1", "+", "1", "2", "+"]
Returns the substring of the target string from its beginning up to the first match in self
(that is, self[0]
); equivalent to regexp global variable $`
:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.pre_match # => "T"
Related: MatchData#post_match
.
Returns the substring of the target string from the end of the first match in self
(that is, self[0]
) to the end of the string; equivalent to regexp global variable $'
:
m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m[0] # => "HX1138" m.post_match # => ": The Movie"\
Related: MatchData.pre_match
.
This is similar to PrettyPrint::format
but the result has no breaks.
maxwidth
, newline
and genspace
are ignored.
The invocation of breakable
in the block doesn’t break a line and is treated as just an invocation of text
.
Load the given PStore
file. If read_only
is true, the unmarshalled Hash
will be returned. If read_only
is false, a 3-tuple will be returned: the unmarshalled Hash
, a checksum of the data, and the size of the data.
Returns the Ruby source filename and line number containing this proc or nil
if this proc was not defined in Ruby (i.e. native).
Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).
Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native).
Returns an array of the names of the thread-local variables (as Symbols).
thr = Thread.new do Thread.current.thread_variable_set(:cat, 'meow') Thread.current.thread_variable_set("dog", 'woof') end thr.join #=> #<Thread:0x401b3f10 dead> thr.thread_variables #=> [:dog, :cat]
Note that these are not fiber local variables. Please see Thread#[]
and Thread#thread_variable_get
for more details.
Returns true
if the given string (or symbol) exists as a thread-local variable.
me = Thread.current me.thread_variable_set(:oliver, "a") me.thread_variable?(:oliver) #=> true me.thread_variable?(:stanley) #=> false
Note that these are not fiber local variables. Please see Thread#[]
and Thread#thread_variable_get
for more details.
Returns the execution stack for the target thread—an array containing backtrace location objects.
See Thread::Backtrace::Location
for more information.
This method behaves similarly to Kernel#caller_locations
except it applies to a specific thread.
Converts block to a Proc
object (and therefore binds it at the point of call) and registers it for execution when the program exits. If multiple handlers are registered, they are executed in reverse order of registration.
def do_at_exit(str1) at_exit { print str1 } end at_exit { puts "cruel world" } do_at_exit("goodbye ") exit
produces:
goodbye cruel world
Ruby tries to load the library named string relative to the directory containing the requiring file. If the file does not exist a LoadError is raised. Returns true
if the file was loaded and false
if the file was already loaded before.
Returns the current execution stack—an array containing backtrace location objects.
See Thread::Backtrace::Location
for more information.
The optional start parameter determines the number of initial stack entries to omit from the top of the stack.
A second optional length
parameter can be used to limit how many entries are returned from the stack.
Returns nil
if start is greater than the size of current execution stack.
Optionally you can pass a range, which will return an array containing the entries within the specified range.
Returns an array of flattened objects returned by the block.
With a block given, calls the block with successive elements; returns a flattened array of objects returned by the block:
[0, 1, 2, 3].flat_map {|element| -element } # => [0, -1, -2, -3] [0, 1, 2, 3].flat_map {|element| [element, -element] } # => [0, 0, 1, -1, 2, -2, 3, -3] [[0, 1], [2, 3]].flat_map {|e| e + [100] } # => [0, 1, 100, 2, 3, 100] {foo: 0, bar: 1, baz: 2}.flat_map {|key, value| [key, value] } # => [:foo, 0, :bar, 1, :baz, 2]
With no block given, returns an Enumerator
.
Alias: collect_concat
.
Returns an array of flattened objects returned by the block.
With a block given, calls the block with successive elements; returns a flattened array of objects returned by the block:
[0, 1, 2, 3].flat_map {|element| -element } # => [0, -1, -2, -3] [0, 1, 2, 3].flat_map {|element| [element, -element] } # => [0, 0, 1, -1, 2, -2, 3, -3] [[0, 1], [2, 3]].flat_map {|e| e + [100] } # => [0, 1, 100, 2, 3, 100] {foo: 0, bar: 1, baz: 2}.flat_map {|key, value| [key, value] } # => [:foo, 0, :bar, 1, :baz, 2]
With no block given, returns an Enumerator
.
Alias: collect_concat
.
Sets create identifier, which is used to decide if the json_create hook of a class should be called; initial value is json_class
:
JSON.create_id # => 'json_class'
Returns the current create identifier. See also JSON.create_id=
.
Arguments obj
and opts
here are the same as arguments obj
and opts
in JSON.generate
.
By default, generates JSON data without checking for circular references in obj
(option max_nesting
set to false
, disabled).
Raises an exception if obj
contains circular references:
a = []; b = []; a.push(b); b.push(a) # Raises SystemStackError (stack level too deep): JSON.fast_generate(a)
Arguments obj
and opts
here are the same as arguments obj
and opts
in JSON.generate
.
Default options are:
{ indent: ' ', # Two spaces space: ' ', # One space array_nl: "\n", # Newline object_nl: "\n" # Newline }
Example:
obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}} json = JSON.pretty_generate(obj) puts json
Output:
{ "foo": [ "bar", "baz" ], "bat": { "bam": 0, "bad": 1 } }