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"]]
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.
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 elements from self; does not modify self.
When no argument is given, returns the first element:
a = [:foo, 'bar', 2] a.first # => :foo a # => [:foo, "bar", 2]
If self is empty, returns nil.
When non-negative Integer argument n is given, returns the first n elements in a new Array:
a = [:foo, 'bar', 2] a.first(2) # => [:foo, "bar"]
If n >= array.size, returns all elements:
a = [:foo, 'bar', 2] a.first(50) # => [:foo, "bar", 2]
If n == 0 returns an new empty Array:
a = [:foo, 'bar', 2] a.first(0) # []
Related: last.
Returns elements from self; self is not modified.
When no argument is given, returns the last element:
a = [:foo, 'bar', 2] a.last # => 2 a # => [:foo, "bar", 2]
If self is empty, returns nil.
When non-negative Innteger argument n is given, returns the last n elements in a new Array:
a = [:foo, 'bar', 2] a.last(2) # => ["bar", 2]
If n >= array.size, returns all elements:
a = [:foo, 'bar', 2] a.last(50) # => [:foo, "bar", 2]
If n == 0, returns an new empty Array:
a = [:foo, 'bar', 2] a.last(0) # []
Related: first.
Returns the index of the last element for which object == element.
When argument object is given but no block, 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.
When a block is given but no argument, 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:
a = [:foo, 'bar', 2, 'bar'] e = a.rindex e # => #<Enumerator: [:foo, "bar", 2, "bar"]:rindex> e.each {|element| element == 'bar' } # => 3
Related: index.
When no block given, returns a new Array new_array of size self.size whose elements are Arrays.
Each nested array new_array[n] is of size other_arrays.size+1, and contains:
The nth element of self.
The nth element of each of the other_arrays.
If all other_arrays and self are the same size:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3] c = [:c0, :c1, :c2, :c3] d = a.zip(b, c) d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
If any array in other_arrays is smaller than self, fills to self.size with nil:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2] c = [:c0, :c1] d = a.zip(b, c) d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, nil], [:a3, nil, nil]]
If any array in other_arrays is larger than self, its trailing elements are ignored:
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3, :b4] c = [:c0, :c1, :c2, :c3, :c4, :c5] d = a.zip(b, c) d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
When a block is given, calls the block with each of the sub-arrays (formed as above); returns nil
a = [:a0, :a1, :a2, :a3] b = [:b0, :b1, :b2, :b3] c = [:c0, :c1, :c2, :c3] a.zip(b, c) {|sub_array| p sub_array} # => nil
Output:
[:a0, :b0, :c0] [:a1, :b1, :c1] [:a2, :b2, :c2] [:a3, :b3, :c3]
Transposes the rows and columns in an Array of Arrays; the nested Arrays must all be the same size:
a = [[:a0, :a1], [:b0, :b1], [:c0, :c1]] a.transpose # => [[:a0, :b0, :c0], [:a1, :b1, :c1]]
Returns a Hash containing implementation-dependent counters inside the VM.
This hash includes information about method/constant cache serials:
{
: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 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 +step+ (which may not be zero).
- Ends with the last number that is within or equal to +limit+;
that is, less than or equal to +limit+ if +step+ is positive,
greater than or equal to +limit+ if +step+ is negative.
If +limit+ is not given, 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.
<b>Keyword Arguments</b>
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
<b>Positional Arguments</b>
With optional positional arguments +limit+ and +step+,
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 <i>floor(n + n*Float::EPSILON) + 1</i> times, where <i>n = (limit - self)/step</i>.
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.
If integer is greater than the length of str, returns a new String of length integer with str left justified and padded with padstr; otherwise, returns str.
"hello".ljust(4) #=> "hello" "hello".ljust(20) #=> "hello " "hello".ljust(20, '1234') #=> "hello123412341234123"
If integer is greater than the length of str, returns a new String of length integer with str right justified and padded with padstr; otherwise, returns str.
"hello".rjust(4) #=> "hello" "hello".rjust(20) #=> " hello" "hello".rjust(20, '1234') #=> "123412341234123hello"
Returns a copy of str with the characters in from_str replaced by the corresponding characters in to_str. If to_str is shorter than from_str, it is padded with its last character in order to maintain the correspondence.
"hello".tr('el', 'ip') #=> "hippo" "hello".tr('aeiou', '*') #=> "h*ll*" "hello".tr('aeiou', 'AA*') #=> "hAll*"
Both strings may use the c1-c2 notation to denote ranges of characters, and from_str may start with a ^, which denotes all characters except those listed.
"hello".tr('a-y', 'b-z') #=> "ifmmp" "hello".tr('^aeiou', '*') #=> "*e**o"
The backslash character \ can be used to escape ^ or - and is otherwise ignored unless it appears at the end of a range or the end of the from_str or to_str:
"hello^world".tr("\\^aeiou", "*") #=> "h*ll**w*rld" "hello-world".tr("a\\-eo", "*") #=> "h*ll**w*rld" "hello\r\nworld".tr("\r", "") #=> "hello\nworld" "hello\r\nworld".tr("\\r", "") #=> "hello\r\nwold" "hello\r\nworld".tr("\\\r", "") #=> "hello\nworld" "X['\\b']".tr("X\\", "") #=> "['b']" "X['\\b']".tr("X-\\]", "") #=> "'b'"