Parses a C struct’s members
Example:
require 'fiddle/import' include Fiddle::CParser #=> Object parse_struct_signature(['int i', 'char c']) #=> [[Fiddle::TYPE_INT, Fiddle::TYPE_CHAR], ["i", "c"]] parse_struct_signature(['char buffer[80]']) #=> [[[Fiddle::TYPE_CHAR, 80]], ["buffer"]]
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 first element, or the first n
elements, of the array. If the array is empty, the first form returns nil
, and the second form returns an empty array. See also Array#last
for the opposite effect.
a = [ "q", "r", "s", "t" ] a.first #=> "q" a.first(2) #=> ["q", "r"]
Returns the last element(s) of self
. If the array is empty, the first form returns nil
.
See also Array#first
for the opposite effect.
a = [ "w", "x", "y", "z" ] a.last #=> "z" a.last(2) #=> ["y", "z"]
Returns the index of the last object in self
==
to obj
.
If a block is given instead of an argument, returns the index of the first object for which the block returns true
, starting from the last object.
Returns nil
if no match is found.
See also Array#index
.
If neither block nor argument is given, an Enumerator
is returned instead.
a = [ "a", "b", "b", "b", "c" ] a.rindex("b") #=> 3 a.rindex("z") #=> nil a.rindex {|x| x == "b"} #=> 3
Converts any arguments to arrays, then merges elements of self
with corresponding elements from each argument.
This generates a sequence of ary.size
n-element arrays, where n is one more than the count of arguments.
If the size of any argument is less than the size of the initial array, nil
values are supplied.
If a block is given, it is invoked for each output array
, otherwise an array of arrays is returned.
a = [ 4, 5, 6 ] b = [ 7, 8, 9 ] [1, 2, 3].zip(a, b) #=> [[1, 4, 7], [2, 5, 8], [3, 6, 9]] [1, 2].zip(a, b) #=> [[1, 4, 7], [2, 5, 8]] a.zip([1, 2], [8]) #=> [[4, 1, 8], [5, 2, nil], [6, nil, nil]]
Assumes that self
is an array of arrays and transposes the rows and columns.
a = [[1,2], [3,4], [5,6]] a.transpose #=> [[1, 3, 5], [2, 4, 6]]
If the length of the subarrays don’t match, an IndexError
is raised.
Returns a Hash
containing implementation-dependent counters inside the VM.
This hash includes information about method/constant cache serials:
{ :global_method_state=>251, :global_constant_state=>481, :class_serial=>9029 }
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 a Digest
subclass by name
in a thread-safe manner even when on-demand loading is involved.
require 'digest' Digest("MD5") # => Digest::MD5 Digest(:SHA256) # => Digest::SHA256 Digest(:Foo) # => LoadError: library not found for class Digest::Foo -- digest/foo
Returns true if self
is a prime number, else returns false.
Returns int
truncated (toward zero) to a precision of ndigits
decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs
trailing zeros.
Returns self
when ndigits
is zero or positive.
1.truncate #=> 1 1.truncate(2) #=> 1 18.truncate(-1) #=> 10 (-18).truncate(-1) #=> -10
Returns num
truncated (toward zero) to a precision of ndigits
decimal digits (default: 0).
Numeric
implements this by converting its value to a Float
and invoking Float#truncate
.
Invokes the given block with the sequence of numbers starting at num
, incremented by step
(defaulted to 1
) on each call.
The loop finishes when the value to be passed to the block is greater than limit
(if step
is positive) or less than limit
(if step
is negative), where limit
is defaulted to infinity.
In the recommended keyword argument style, either or both of step
and limit
(default infinity) can be omitted. In the fixed position argument style, zero as a step (i.e. num.step(limit, 0)
) is not allowed for historical compatibility reasons.
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 - num)/step.
Otherwise, the loop starts at num
, uses either the less-than (<
) or greater-than (>
) operator to compare the counter against limit
, and increments itself using the +
operator.
If no block is given, an Enumerator
is returned instead. Especially, the enumerator is an Enumerator::ArithmeticSequence
if both limit
and step
are kind of Numeric
or nil
.
For example:
p 1.step.take(4) p 10.step(by: -1).take(4) 3.step(to: 5) {|i| print i, " " } 1.step(10, 2) {|i| print i, " " } Math::E.step(to: Math::PI, by: 0.2) {|f| print f, " " }
Will produce:
[1, 2, 3, 4] [10, 9, 8, 7] 3 4 5 1 3 5 7 9 2.718281828459045 2.9182818284590453 3.118281828459045