Returns the character position of the scan pointer. In the ‘reset’ position, this value is zero. In the ‘terminated’ position (i.e. the string is exhausted), this value is the size of the string.
In short, it’s a 0-based index into the string.
s = StringScanner.new("abcädeföghi") s.charpos # -> 0 s.scan_until(/ä/) # -> "abcä" s.pos # -> 5 s.charpos # -> 4
Tests whether the given pattern is matched from the current scan pointer. Returns the length of the match, or nil. The scan pointer is not advanced.
s = StringScanner.new('test string') p s.match?(/\w+/) # -> 4 p s.match?(/\w+/) # -> 4 p s.match?("test") # -> 4 p s.match?(/\s+/) # -> nil
This returns the value that scan would return, without advancing the scan pointer. The match register is affected, though.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.check /Fri/ # -> "Fri" s.pos # -> 0 s.matched # -> "Fri" s.check /12/ # -> nil s.matched # -> nil
Mnemonic: it “checks” to see whether a scan will return a value.
Scans one character and returns it. This method is multibyte character sensitive.
s = StringScanner.new("ab") s.getch # => "a" s.getch # => "b" s.getch # => nil $KCODE = 'EUC' s = StringScanner.new("\244\242") s.getch # => "\244\242" # Japanese hira-kana "A" in EUC-JP s.getch # => nil
Returns true iff the last match was successful.
s = StringScanner.new('test string') s.match?(/\w+/) # => 4 s.matched? # => true s.match?(/\d+/) # => nil s.matched? # => false
Returns the last matched string.
s = StringScanner.new('test string') s.match?(/\w+/) # -> 4 s.matched # -> "test"
Iterates over each item of OLE collection which has IEnumVARIANT interface.
excel = WIN32OLE.new('Excel.Application') book = excel.workbooks.add sheets = book.worksheets(1) cells = sheets.cells("A1:A5") cells.each do |cell| cell.value = 10 end
Returns help string of OLE method. If the help string is not found, then the method returns nil.
tobj = WIN32OLE_TYPE.new('Microsoft Internet Controls', 'IWebBrowser') method = WIN32OLE_METHOD.new(tobj, 'Navigate') puts method.helpstring # => Navigates to a URL or file.
Returns help string.
tobj = WIN32OLE_TYPE.new('Microsoft Internet Controls', 'IWebBrowser') puts tobj.helpstring # => Web Browser interface
Returns a value from the hash for the given key. If the key can’t be found, there are several options: With no other arguments, it will raise a KeyError exception; if default is given, then that will be returned; if the optional code block is specified, then that will be run and its result returned.
h = { "a" => 100, "b" => 200 } h.fetch("a") #=> 100 h.fetch("z", "go fish") #=> "go fish" h.fetch("z") { |el| "go fish, #{el}"} #=> "go fish, z"
The following example shows that an exception is raised if the key is not found and a default value is not supplied.
h = { "a" => 100, "b" => 200 } h.fetch("z")
produces:
prog.rb:2:in `fetch': key not found (KeyError) from prog.rb:2
Calls block once for each key in hsh, passing the key-value pair as parameters.
If no block is given, an enumerator is returned instead.
h = { "a" => 100, "b" => 200 } h.each {|key, value| puts "#{key} is #{value}" }
produces:
a is 100 b is 200
If name is the name of an environment variable, returns its value:
ENV['foo'] = '0' ENV.fetch('foo') # => '0'
Otherwise if a block is given (but not a default value), yields name to the block and returns the block’s return value:
ENV.fetch('foo') { |name| :need_not_return_a_string } # => :need_not_return_a_string
Otherwise if a default value is given (but not a block), returns the default value:
ENV.delete('foo') ENV.fetch('foo', :default_need_not_be_a_string) # => :default_need_not_be_a_string
If the environment variable does not exist and both default and block are given, issues a warning (“warning: block supersedes default value argument”), yields name to the block, and returns the block’s return value:
ENV.fetch('foo', :default) { |name| :block_return } # => :block_return
Raises KeyError if name is valid, but not found, and neither default value nor block is given:
ENV.fetch('foo') # Raises KeyError (key not found: "foo")
Raises an exception if name is invalid. See Invalid Names and Values.
Yields each environment variable name and its value as a 2-element Array:
h = {} ENV.each_pair { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
Returns an Enumerator if no block given:
h = {} e = ENV.each_pair # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_pair> e.each { |name, value| h[name] = value } # => ENV h # => {"bar"=>"1", "foo"=>"0"}
Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is an Integer specifying the maximum length of each line; longer lines will be split according to this limit.
This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename of the current line and line number of the whole input, respectively.
For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:
ARGF.each_line do |line| puts ARGF.filename if ARGF.file.lineno == 1 puts "#{ARGF.file.lineno}: #{line}" end
While the following code prints only the first file’s name at first, and the contents with line number counted through all named files.
ARGF.each_line do |line| puts ARGF.filename if ARGF.lineno == 1 puts "#{ARGF.lineno}: #{line}" end
This is a deprecated alias for each_char.
Reads the next character from ARGF and returns it as a String. Raises an EOFError after the last character of the last file has been read.
For example:
$ echo "foo" > file $ ruby argf.rb file ARGF.readchar #=> "f" ARGF.readchar #=> "o" ARGF.readchar #=> "o" ARGF.readchar #=> "\n" ARGF.readchar #=> end of file reached (EOFError)
This method is intended as the primary interface for reading CSV files. You pass a path and any options you wish to set for the read. Each row of file will be passed to the provided block in turn.
The options parameter can be anything CSV::new() understands. This method also understands an additional :encoding parameter that you can use to specify the Encoding of the data in the file to be read. You must provide this unless your data is in Encoding::default_external(). CSV will use this to determine how to parse the data. You may provide a second Encoding to have the data transcoded as it is read. For example, encoding: "UTF-32BE:UTF-8" would read UTF-32BE data from the file but transcode it to UTF-8 before CSV parses it.
Yields each row of the data source in turn.
Support for Enumerable.
The data source must be open for reading.
Iterator version of ‘get’.
The block is called repeatedly with two arguments: The first is the option name. The second is the argument which followed it (if any). Example: (‘–opt’, ‘value’)
The option name is always converted to the first (preferred) name given in the original options to GetoptLong.new.
Yields all elements of the matrix, starting with those of the first row, or returns an Enumerator if no block given. Elements can be restricted by passing an argument:
:all (default): yields all elements
:diagonal: yields only elements on the diagonal
:off_diagonal: yields all elements except on the diagonal
:lower: yields only elements on or below the diagonal
:strict_lower: yields only elements below the diagonal
:strict_upper: yields only elements above the diagonal
:upper: yields only elements on or above the diagonal
Matrix[ [1,2], [3,4] ].each { |e| puts e }
# => prints the numbers 1 to 4
Matrix[ [1,2], [3,4] ].each(:strict_lower).to_a # => [3]
Returns true if this is a symmetric matrix. Raises an error if matrix is not square.
Returns true if this is an antisymmetric matrix. Raises an error if matrix is not square.
Returns the Eigensystem of the matrix; see EigenvalueDecomposition.
m = Matrix[[1, 2], [3, 4]] v, d, v_inv = m.eigensystem d.diagonal? # => true v.inv == v_inv # => true (v * d * v_inv).round(5) == m # => true
Iterate over the elements of this vector
Iterate over the elements of this vector and v in conjunction.