Results for: "remove_const"

Racc::RRconflict

No documentation available

Reline::Config

No documentation available

Gem::ConfigFile

Gem::ConfigFile RubyGems options and gem command options from gemrc.

gemrc is a YAML file that uses strings to match gem command arguments and symbols to match RubyGems options.

Gem command arguments use a String key that matches the command name and allow you to specify default arguments:

install: --no-rdoc --no-ri
update: --no-rdoc --no-ri

You can use gem: to set default arguments for all commands.

RubyGems options use symbol keys. Valid options are:

:backtrace

See backtrace

:sources

Sets Gem::sources

:verbose

See verbose

:concurrent_downloads

See concurrent_downloads

gemrc files may exist in various locations and are read and merged in the following order:

Gem::DependencyInstaller

Installs a gem along with all its dependencies from local and remote gems.

Gem::ConflictError

Raised when there are conflicting gem specs loaded

Gem::UninstallError

Raised when removing a gem with the uninstall command fails

Gem::InstallError

No documentation available

Gem::InvalidSpecificationException

Potentially raised when a specification is validated.

Gem::Installer

The installer installs the files contained in the .gem into the Gem.home.

Gem::Installer does the work of putting files in all the right places on the filesystem including unpacking the gem into its gem dir, installing the gemspec in the specifications dir, storing the cached gem in the cache dir, and installing either wrappers or symlinks for executables.

The installer invokes pre and post install hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_install and Gem.post_install for details.

Gem::StubSpecification

Gem::StubSpecification reads the stub: line from the gemspec. This prevents us having to eval the entire gemspec in order to find out certain information.

Gem::Uninstaller

An Uninstaller.

The uninstaller fires pre and post uninstall hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_uninstall and Gem.post_uninstall for details.

SyntaxSuggest::CodeFrontier

There are three main phases in the algorithm:

  1. Sanitize/format input source

  2. Search for invalid blocks

  3. Format invalid blocks into something meaninful

The Code frontier is a critical part of the second step

## Knowing where we’ve been

Once a code block is generated it is added onto the frontier. Then it will be sorted by indentation and frontier can be filtered. Large blocks that fully enclose a smaller block will cause the smaller block to be evicted.

CodeFrontier#<<(block) # Adds block to frontier
CodeFrontier#pop # Removes block from frontier

## Knowing where we can go

Internally the frontier keeps track of “unvisited” lines which are exposed via ‘next_indent_line` when called, this method returns, a line of code with the highest indentation.

The returned line of code can be used to build a CodeBlock and then that code block is added back to the frontier. Then, the lines are removed from the “unvisited” so we don’t double-create the same block.

CodeFrontier#next_indent_line # Shows next line
CodeFrontier#register_indent_block(block) # Removes lines from unvisited

## Knowing when to stop

The frontier knows how to check the entire document for a syntax error. When blocks are added onto the frontier, they’re removed from the document. When all code containing syntax errors has been added to the frontier, the document will be parsable without a syntax error and the search can stop.

CodeFrontier#holds_all_syntax_errors? # Returns true when frontier holds all syntax errors

## Filtering false positives

Once the search is completed, the frontier may have multiple blocks that do not contain the syntax error. To limit the result to the smallest subset of “invalid blocks” call:

CodeFrontier#detect_invalid_blocks

URI::InvalidComponentError

Not a URI component.

Digest::Instance

This module provides instance methods for a digest implementation object to calculate message digest values.

CGI::QueryExtension

Mixin module that provides the following:

  1. Access to the CGI environment variables as methods. See documentation to the CGI class for a list of these variables. The methods are exposed by removing the leading HTTP_ (if it exists) and downcasing the name. For example, auth_type will return the environment variable AUTH_TYPE, and accept will return the value for HTTP_ACCEPT.

  2. Access to cookies, including the cookies attribute.

  3. Access to parameters, including the params attribute, and overloading [] to perform parameter value lookup by key.

  4. The initialize_query method, for initializing the above mechanisms, handling multipart forms, and allowing the class to be used in “offline” mode.

CGI::HtmlExtension

Mixin module providing HTML generation methods.

For example,

cgi.a("http://www.example.com") { "Example" }
  # => "<A HREF=\"http://www.example.com\">Example</A>"

Modules Html3, Html4, etc., contain more basic HTML-generation methods (#title, #h1, etc.).

See class CGI for a detailed example.

MakeMakefile::RbConfig

No documentation available

Net::HTTPExceptions

Net::HTTP exception class. You cannot use Net::HTTPExceptions directly; instead, you must use its subclasses.

OptionParser::Completion

Keyword completion module. This allows partial arguments to be specified and resolved against a list of acceptable values.

Gem::UpdateSuggestion

Mixin methods for Gem::Command to promote available RubyGems update

Complex

A complex number can be represented as a paired real number with imaginary unit; a+bi. Where a is real part, b is imaginary part and i is imaginary unit. Real a equals complex a+0i mathematically.

You can create a Complex object explicitly with:

You can convert certain objects to Complex objects with:

Complex object can be created as literal, and also by using Kernel#Complex, Complex::rect, Complex::polar or to_c method.

2+1i                 #=> (2+1i)
Complex(1)           #=> (1+0i)
Complex(2, 3)        #=> (2+3i)
Complex.polar(2, 3)  #=> (-1.9799849932008908+0.2822400161197344i)
3.to_c               #=> (3+0i)

You can also create complex object from floating-point numbers or strings.

Complex(0.3)         #=> (0.3+0i)
Complex('0.3-0.5i')  #=> (0.3-0.5i)
Complex('2/3+3/4i')  #=> ((2/3)+(3/4)*i)
Complex('1@2')       #=> (-0.4161468365471424+0.9092974268256817i)

0.3.to_c             #=> (0.3+0i)
'0.3-0.5i'.to_c      #=> (0.3-0.5i)
'2/3+3/4i'.to_c      #=> ((2/3)+(3/4)*i)
'1@2'.to_c           #=> (-0.4161468365471424+0.9092974268256817i)

A complex object is either an exact or an inexact number.

Complex(1, 1) / 2    #=> ((1/2)+(1/2)*i)
Complex(1, 1) / 2.0  #=> (0.5+0.5i)

String

A String object has an arbitrary sequence of bytes, typically representing text or binary data. A String object may be created using String::new or as literals.

String objects differ from Symbol objects in that Symbol objects are designed to be used as identifiers, instead of text or data.

You can create a String object explicitly with:

You can convert certain objects to Strings with:

Some String methods modify self. Typically, a method whose name ends with ! modifies self and returns self; often a similarly named method (without the !) returns a new string.

In general, if there exist both bang and non-bang version of method, the bang! mutates and the non-bang! does not. However, a method without a bang can also mutate, such as String#replace.

Substitution Methods

These methods perform substitutions:

Each of these methods takes:

The examples in this section mostly use methods String#sub and String#gsub; the principles illustrated apply to all four substitution methods.

Argument pattern

Argument pattern is commonly a regular expression:

s = 'hello'
s.sub(/[aeiou]/, '*')# => "h*llo"
s.gsub(/[aeiou]/, '*') # => "h*ll*"
s.gsub(/[aeiou]/, '')# => "hll"
s.sub(/ell/, 'al')   # => "halo"
s.gsub(/xyzzy/, '*') # => "hello"
'THX1138'.gsub(/\d+/, '00') # => "THX00"

When pattern is a string, all its characters are treated as ordinary characters (not as regexp special characters):

'THX1138'.gsub('\d+', '00') # => "THX1138"

String replacement

If replacement is a string, that string will determine the replacing string that is to be substituted for the matched text.

Each of the examples above uses a simple string as the replacing string.

String replacement may contain back-references to the pattern’s captures:

See regexp.rdoc for details.

Note that within the string replacement, a character combination such as $& is treated as ordinary text, and not as a special match variable. However, you may refer to some special match variables using these combinations:

See regexp.rdoc for details.

Note that \\ is interpreted as an escape, i.e., a single backslash.

Note also that a string literal consumes backslashes. See string literal for details about string literals.

A back-reference is typically preceded by an additional backslash. For example, if you want to write a back-reference \& in replacement with a double-quoted string literal, you need to write "..\\&..".

If you want to write a non-back-reference string \& in replacement, you need first to escape the backslash to prevent this method from interpreting it as a back-reference, and then you need to escape the backslashes again to prevent a string literal from consuming them: "..\\\\&..".

You may want to use the block form to avoid a lot of backslashes.

Hash replacement

If argument replacement is a hash, and pattern matches one of its keys, the replacing string is the value for that key:

h = {'foo' => 'bar', 'baz' => 'bat'}
'food'.sub('foo', h) # => "bard"

Note that a symbol key does not match:

h = {foo: 'bar', baz: 'bat'}
'food'.sub('foo', h) # => "d"

Block

In the block form, the current match string is passed to the block; the block’s return value becomes the replacing string:

 s = '@'
'1234'.gsub(/\d/) {|match| s.succ! } # => "ABCD"

Special match variables such as $1, $2, $`, $&, and $' are set appropriately.

Whitespace in Strings

In class String, whitespace is defined as a contiguous sequence of characters consisting of any mixture of the following:

Whitespace is relevant for these methods:

String Slices

A slice of a string is a substring that is selected by certain criteria.

These instance methods make use of slicing:

Each of the above methods takes arguments that determine the slice to be copied or replaced.

The arguments have several forms. For string string, the forms are:

string[index]

When non-negative integer argument index is given, the slice is the 1-character substring found in self at character offset index:

'bar'[0]       # => "b"
'bar'[2]       # => "r"
'bar'[20]      # => nil
'тест'[2]      # => "с"
'こんにちは'[4]  # => "は"

When negative integer index is given, the slice begins at the offset given by counting backward from the end of self:

'bar'[-3]         # => "b"
'bar'[-1]         # => "r"
'bar'[-20]        # => nil

string[start, length]

When non-negative integer arguments start and length are given, the slice begins at character offset start, if it exists, and continues for length characters, if available:

'foo'[0, 2]       # => "fo"
'тест'[1, 2]      # => "ес"
'こんにちは'[2, 2]  # => "にち"
# Zero length.
'foo'[2, 0]       # => ""
# Length not entirely available.
'foo'[1, 200]     # => "oo"
# Start out of range.
'foo'[4, 2]      # => nil

Special case: if start is equal to the length of self, the slice is a new empty string:

'foo'[3, 2]   # => ""
'foo'[3, 200] # => ""

When negative start and non-negative length are given, the slice beginning is determined by counting backward from the end of self, and the slice continues for length characters, if available:

'foo'[-2, 2]    # => "oo"
'foo'[-2, 200]  # => "oo"
# Start out of range.
'foo'[-4, 2]     # => nil

When negative length is given, there is no slice:

'foo'[1, -1]  # => nil
'foo'[-2, -1] # => nil

string[range]

When Range argument range is given, creates a substring of string using the indices in range. The slice is then determined as above:

'foo'[0..1]    # => "fo"
'foo'[0, 2]    # => "fo"

'foo'[2...2]   # => ""
'foo'[2, 0]    # => ""

'foo'[1..200]  # => "oo"
'foo'[1, 200]  # => "oo"

'foo'[4..5]    # => nil
'foo'[4, 2]    # => nil

'foo'[-4..-3]  # => nil
'foo'[-4, 2]   # => nil

'foo'[3..4]    # => ""
'foo'[3, 2]    # => ""

'foo'[-2..-1]  # => "oo"
'foo'[-2, 2]   # => "oo"

'foo'[-2..197] # => "oo"
'foo'[-2, 200] # => "oo"

string[regexp, capture = 0]

When the Regexp argument regexp is given, and the capture argument is 0, the slice is the first matching substring found in self:

'foo'[/o/] # => "o"
'foo'[/x/] # => nil
s = 'hello there'
s[/[aeiou](.)\1/] # => "ell"
s[/[aeiou](.)\1/, 0] # => "ell"

If argument capture is given and not 0, it should be either an capture group index (integer) or a capture group name (string or symbol); the slice is the specified capture (see Capturing at Regexp):

s = 'hello there'
s[/[aeiou](.)\1/, 1] # => "l"
s[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, "non_vowel"] # => "l"
s[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, :vowel] # => "e"

If an invalid capture group index is given, there is no slice. If an invalid capture group name is given, IndexError is raised.

string[substring]

When the single String argument substring is given, returns the substring from self if found, otherwise nil:

'foo'['oo'] # => "oo"
'foo'['xx'] # => nil

What’s Here

First, what’s elsewhere. Class String:

Here, class String provides methods that are useful for:

Methods for Creating a String

Methods for a Frozen/Unfrozen String

Methods for Querying

Counts

Substrings

Encodings

Other

Methods for Comparing

Methods for Modifying a String

Each of these methods modifies self.

Insertion

Substitution

Casing

Encoding

Deletion

Methods for Converting to New String

Each of these methods returns a new String based on self, often just a modified copy of self.

Extension

Encoding

Substitution

Casing

Deletion

Duplication

Methods for Converting to Non-String

Each of these methods converts the contents of self to a non-String.

Characters, Bytes, and Clusters

Splitting

Matching

Numerics

Strings and Symbols

Methods for Iterating

Encoding

An Encoding instance represents a character encoding usable in Ruby. It is defined as a constant under the Encoding namespace. It has a name and, optionally, aliases:

Encoding::US_ASCII.name  # => "US-ASCII"
Encoding::US_ASCII.names # => ["US-ASCII", "ASCII", "ANSI_X3.4-1968", "646"]

A Ruby method that accepts an encoding as an argument will accept:

These are equivalent:

'foo'.encode(Encoding::US_ASCII) # Encoding object.
'foo'.encode('US-ASCII')         # Encoding name.
'foo'.encode('ASCII')            # Encoding alias.

For a full discussion of encodings and their uses, see the Encodings document.

Encoding::ASCII_8BIT is a special-purpose encoding that is usually used for a string of bytes, not a string of characters. But as the name indicates, its characters in the ASCII range are considered as ASCII characters. This is useful when you use other ASCII-compatible encodings.

Exception

Class Exception and its subclasses are used to communicate between Kernel#raise and rescue statements in begin ... end blocks.

An Exception object carries information about an exception:

Some built-in subclasses of Exception have additional methods: e.g., NameError#name.

Defaults

Two Ruby statements have default exception classes:

Global Variables

When an exception has been raised but not yet handled (in rescue, ensure, at_exit and END blocks), two global variables are set:

Custom Exceptions

To provide additional or alternate information, a program may create custom exception classes that derive from the built-in exception classes.

A good practice is for a library to create a single “generic” exception class (typically a subclass of StandardError or RuntimeError) and have its other exception classes derive from that class. This allows the user to rescue the generic exception, thus catching all exceptions the library may raise even if future versions of the library add new exception subclasses.

For example:

class MyLibrary
  class Error < ::StandardError
  end

  class WidgetError < Error
  end

  class FrobError < Error
  end

end

To handle both MyLibrary::WidgetError and MyLibrary::FrobError the library user can rescue MyLibrary::Error.

Built-In Exception Classes

The built-in subclasses of Exception are:

SignalException

Raised when a signal is received.

begin
  Process.kill('HUP',Process.pid)
  sleep # wait for receiver to handle signal sent by Process.kill
rescue SignalException => e
  puts "received Exception #{e}"
end

produces:

received Exception SIGHUP
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