@foo &&= bar
becomes
@foo && @foo = bar
@foo ||= bar
becomes
@foo || @foo = bar
@foo += bar
becomes
@foo = @foo + bar
Returns the original source code as an array of lines.
Note that this is an API for ruby internal use, debugging, and research. Do not use this for any other purpose. The compatibility is not guaranteed.
Implement the hash pattern matching interface for Result
.
Ensures the root of chain
has a trusted certificate in trust_dir
and the digests of the two certificates match according to digester
Add a certificate to trusted certificate list.
Returns the index of the last element for which object == element
.
With argument object
given, returns the index of the last such element found:
a = [:foo, 'bar', 2, 'bar'] a.rindex('bar') # => 3
Returns nil
if no such object found.
With a block given, calls the block with each successive element; returns the index of the last element for which the block returns a truthy value:
a = [:foo, 'bar', 2, 'bar'] a.rindex {|element| element == 'bar' } # => 3
Returns nil
if the block never returns a truthy value.
When neither an argument nor a block is given, returns a new Enumerator
.
Related: see Methods for Querying.
With no block given, combines self
with the collection of other_arrays
; returns a new array of sub-arrays:
[0, 1].zip(['zero', 'one'], [:zero, :one]) # => [[0, "zero", :zero], [1, "one", :one]]
Returned:
The outer array is of size self.size
.
Each sub-array is of size other_arrays.size + 1
.
The nth sub-array contains (in order):
The nth element of self
.
The nth element of each of the other arrays, as available.
Example:
a = [0, 1] zipped = a.zip(['zero', 'one'], [:zero, :one]) # => [[0, "zero", :zero], [1, "one", :one]] zipped.size # => 2 # Same size as a. zipped.first.size # => 3 # Size of other arrays plus 1.
When the other arrays are all the same size as self
, the returned sub-arrays are a rearrangement containing exactly elements of all the arrays (including self
), with no omissions or additions:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3] c = [:c0, :c1, :c2, :c3] d = a.zip(b, c) pp d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
When one of the other arrays is smaller than self
, pads the corresponding sub-array with nil
elements:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2] c = [:c0, :c1] d = a.zip(b, c) pp d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, nil], [:a3, nil, nil]]
When one of the other arrays is larger than self
, ignores its trailing elements:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3, :b4] c = [:c0, :c1, :c2, :c3, :c4, :c5] d = a.zip(b, c) pp d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
With a block given, calls the block with each of the other arrays; returns nil
:
d = [] a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3] c = [:c0, :c1, :c2, :c3] a.zip(b, c) {|sub_array| d.push(sub_array.reverse) } # => nil pp d # => [[:c0, :b0, :a0], [:c1, :b1, :a1], [:c2, :b2, :a2], [:c3, :b3, :a3]]
For an object in other_arrays that is not actually an array, forms the the “other array” as object.to_ary
, if defined, or as object.each.to_a
otherwise.
Related: see Methods for Converting.
Returns a new array that is self
as a transposed matrix:
a = [[:a0, :a1], [:b0, :b1], [:c0, :c1]] a.transpose # => [[:a0, :b0, :c0], [:a1, :b1, :c1]]
The elements of self
must all be the same size.
Related: see Methods for Converting.
Returns elements from self
, or nil
; does not modify self
.
With no argument given, returns the first element (if available):
a = [:foo, 'bar', 2] a.first # => :foo a # => [:foo, "bar", 2]
If self
is empty, returns nil
.
[].first # => nil
With a non-negative integer argument count
given, returns the first count
elements (as available) in a new array:
a.first(0) # => [] a.first(2) # => [:foo, "bar"] a.first(50) # => [:foo, "bar", 2]
Related: see Methods for Querying.
Returns elements from self
, or nil
; self
is not modified.
With no argument given, returns the last element, or nil
if self
is empty:
a = [:foo, 'bar', 2] a.last # => 2 a # => [:foo, "bar", 2] [].last # => nil
With non-negative integer argument count
given, returns a new array containing the trailing count
elements of self
, as available:
a = [:foo, 'bar', 2] a.last(2) # => ["bar", 2] a.last(50) # => [:foo, "bar", 2] a.last(0) # => [] [].last(3) # => []
Related: see Methods for Fetching.
Returns a Hash
containing implementation-dependent counters inside the VM.
This hash includes information about method/constant caches:
{ :constant_cache_invalidations=>2, :constant_cache_misses=>14, :global_cvar_state=>27 }
If USE_DEBUG_COUNTER
is enabled, debug counters will be included.
The contents of the hash are implementation specific and may be changed in the future.
This method is only expected to work on C Ruby
.
Returns self
truncated (toward zero) to a precision of ndigits
decimal digits.
When ndigits
is negative, the returned value has at least ndigits.abs
trailing zeros:
555.truncate(-1) # => 550 555.truncate(-2) # => 500 -555.truncate(-2) # => -500
Returns self
when ndigits
is zero or positive.
555.truncate # => 555 555.truncate(50) # => 555
Related: Integer#round
.
Returns self
truncated (toward zero) to a precision of digits
decimal digits.
Numeric implements this by converting self
to a Float
and invoking Float#truncate
.
Generates a sequence of numbers; with a block given, traverses the sequence.
Of the Core and Standard Library classes, Integer
, Float
, and Rational
use this implementation.
A quick example:
squares = [] 1.step(by: 2, to: 10) {|i| squares.push(i*i) } squares # => [1, 9, 25, 49, 81]
The generated sequence:
Begins with self
.
Continues at intervals of by
(which may not be zero).
Ends with the last number that is within or equal to to
; that is, less than or equal to to
if by
is positive, greater than or equal to to
if by
is negative. If to
is nil
, the sequence is of infinite length.
If a block is given, calls the block with each number in the sequence; returns self
. If no block is given, returns an Enumerator::ArithmeticSequence
.
Keyword Arguments
With keyword arguments by
and to
, their values (or defaults) determine the step and limit:
# Both keywords given. squares = [] 4.step(by: 2, to: 10) {|i| squares.push(i*i) } # => 4 squares # => [16, 36, 64, 100] cubes = [] 3.step(by: -1.5, to: -3) {|i| cubes.push(i*i*i) } # => 3 cubes # => [27.0, 3.375, 0.0, -3.375, -27.0] squares = [] 1.2.step(by: 0.2, to: 2.0) {|f| squares.push(f*f) } squares # => [1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0] squares = [] Rational(6/5).step(by: 0.2, to: 2.0) {|r| squares.push(r*r) } squares # => [1.0, 1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0] # Only keyword to given. squares = [] 4.step(to: 10) {|i| squares.push(i*i) } # => 4 squares # => [16, 25, 36, 49, 64, 81, 100] # Only by given. # Only keyword by given squares = [] 4.step(by:2) {|i| squares.push(i*i); break if i > 10 } squares # => [16, 36, 64, 100, 144] # No block given. e = 3.step(by: -1.5, to: -3) # => (3.step(by: -1.5, to: -3)) e.class # => Enumerator::ArithmeticSequence
Positional Arguments
With optional positional arguments to
and by
, their values (or defaults) determine the step and limit:
squares = [] 4.step(10, 2) {|i| squares.push(i*i) } # => 4 squares # => [16, 36, 64, 100] squares = [] 4.step(10) {|i| squares.push(i*i) } squares # => [16, 25, 36, 49, 64, 81, 100] squares = [] 4.step {|i| squares.push(i*i); break if i > 10 } # => nil squares # => [16, 25, 36, 49, 64, 81, 100, 121]
Implementation Notes
If all the arguments are integers, the loop operates using an integer counter.
If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*Float::EPSILON) + 1 times, where n = (limit - self)/step.
Returns the Integer
index of the last occurrence of the given substring
, or nil
if none found:
'foo'.rindex('f') # => 0 'foo'.rindex('o') # => 2 'foo'.rindex('oo') # => 1 'foo'.rindex('ooo') # => nil
Returns the Integer
index of the last match for the given Regexp
regexp
, or nil
if none found:
'foo'.rindex(/f/) # => 0 'foo'.rindex(/o/) # => 2 'foo'.rindex(/oo/) # => 1 'foo'.rindex(/ooo/) # => nil
The last match means starting at the possible last position, not the last of longest matches.
'foo'.rindex(/o+/) # => 2 $~ #=> #<MatchData "o">
To get the last longest match, needs to combine with negative lookbehind.
'foo'.rindex(/(?<!o)o+/) # => 1 $~ #=> #<MatchData "oo">
Or String#index
with negative lookforward.
'foo'.index(/o+(?!.*o)/) # => 1 $~ #=> #<MatchData "oo">
Integer
argument offset
, if given and non-negative, specifies the maximum starting position in the string to end the search:
'foo'.rindex('o', 0) # => nil 'foo'.rindex('o', 1) # => 1 'foo'.rindex('o', 2) # => 2 'foo'.rindex('o', 3) # => 2
If offset
is a negative Integer
, the maximum starting position in the string to end the search is the sum of the string’s length and offset
:
'foo'.rindex('o', -1) # => 2 'foo'.rindex('o', -2) # => 1 'foo'.rindex('o', -3) # => nil 'foo'.rindex('o', -4) # => nil
Related: String#index
.
Returns the Integer
byte-based index of the last occurrence of the given substring
, or nil
if none found:
'foo'.byterindex('f') # => 0 'foo'.byterindex('o') # => 2 'foo'.byterindex('oo') # => 1 'foo'.byterindex('ooo') # => nil
Returns the Integer
byte-based index of the last match for the given Regexp
regexp
, or nil
if none found:
'foo'.byterindex(/f/) # => 0 'foo'.byterindex(/o/) # => 2 'foo'.byterindex(/oo/) # => 1 'foo'.byterindex(/ooo/) # => nil
The last match means starting at the possible last position, not the last of longest matches.
'foo'.byterindex(/o+/) # => 2 $~ #=> #<MatchData "o">
To get the last longest match, needs to combine with negative lookbehind.
'foo'.byterindex(/(?<!o)o+/) # => 1 $~ #=> #<MatchData "oo">
Or String#byteindex
with negative lookforward.
'foo'.byteindex(/o+(?!.*o)/) # => 1 $~ #=> #<MatchData "oo">
Integer
argument offset
, if given and non-negative, specifies the maximum starting byte-based position in the string to end the search:
'foo'.byterindex('o', 0) # => nil 'foo'.byterindex('o', 1) # => 1 'foo'.byterindex('o', 2) # => 2 'foo'.byterindex('o', 3) # => 2
If offset
is a negative Integer
, the maximum starting position in the string to end the search is the sum of the string’s length and offset
:
'foo'.byterindex('o', -1) # => 2 'foo'.byterindex('o', -2) # => 1 'foo'.byterindex('o', -3) # => nil 'foo'.byterindex('o', -4) # => nil
If offset
does not land on character (codepoint) boundary, IndexError
is raised.
Related: String#byteindex
.