Results for: "Logger"

Returns an array of the grapheme clusters in self (see Unicode Grapheme Cluster Boundaries):

s = "\u0061\u0308-pqr-\u0062\u0308-xyz-\u0063\u0308" # => "ä-pqr-b̈-xyz-c̈"
s.grapheme_clusters
# => ["ä", "-", "p", "q", "r", "-", "b̈", "-", "x", "y", "z", "-", "c̈"]

Returns the next-larger representable Float.

These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.next_float:

f = 0.0      # 0x0000000000000000
f.next_float # 0x0000000000000001

f = 0.01     # 0x3f847ae147ae147b
f.next_float # 0x3f847ae147ae147c

In the remaining examples here, the output is shown in the usual way (result to_s):

0.01.next_float    # => 0.010000000000000002
1.0.next_float     # => 1.0000000000000002
100.0.next_float   # => 100.00000000000001

f = 0.01
(0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.next_float }

Output:

 0 0x1.47ae147ae147bp-7 0.01
 1 0x1.47ae147ae147cp-7 0.010000000000000002
 2 0x1.47ae147ae147dp-7 0.010000000000000004
 3 0x1.47ae147ae147ep-7 0.010000000000000005

f = 0.0; 100.times { f += 0.1 }
f                           # => 9.99999999999998       # should be 10.0 in the ideal world.
10-f                        # => 1.9539925233402755e-14 # the floating point error.
10.0.next_float-10          # => 1.7763568394002505e-15 # 1 ulp (unit in the last place).
(10-f)/(10.0.next_float-10) # => 11.0                   # the error is 11 ulp.
(10-f)/(10*Float::EPSILON)  # => 8.8                    # approximation of the above.
"%a" % 10                   # => "0x1.4p+3"
"%a" % f                    # => "0x1.3fffffffffff5p+3" # the last hex digit is 5.  16 - 5 = 11 ulp.

Related: Float#prev_float

Returns the next-smaller representable Float.

These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.pev_float:

f = 5e-324   # 0x0000000000000001
f.prev_float # 0x0000000000000000

f = 0.01     # 0x3f847ae147ae147b
f.prev_float # 0x3f847ae147ae147a

In the remaining examples here, the output is shown in the usual way (result to_s):

0.01.prev_float   # => 0.009999999999999998
1.0.prev_float    # => 0.9999999999999999
100.0.prev_float  # => 99.99999999999999

f = 0.01
(0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.prev_float }

Output:

0 0x1.47ae147ae147bp-7 0.01
1 0x1.47ae147ae147ap-7 0.009999999999999998
2 0x1.47ae147ae1479p-7 0.009999999999999997
3 0x1.47ae147ae1478p-7 0.009999999999999995

Related: Float#next_float.

Like backtrace, but returns each line of the execution stack as a Thread::Backtrace::Location. Accepts the same arguments as backtrace.

f = Fiber.new { Fiber.yield }
f.resume
loc = f.backtrace_locations.first
loc.label  #=> "yield"
loc.path   #=> "test.rb"
loc.lineno #=> 1

Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) call that scheduler’s hook methods on potentially blocking operations, and the current thread will call scheduler’s close method on finalization (allowing the scheduler to properly manage all non-finished fibers).

scheduler can be an object of any class corresponding to Fiber::Scheduler. Its implementation is up to the user.

See also the “Non-blocking fibers” section in class docs.

Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler if and only if the current fiber is non-blocking.

Returns default external encoding.

The default external encoding is used by default for strings created from the following locations:

• CSV

• File data read from disk

• SDBM

• StringIO

• Zlib::GzipReader

• Zlib::GzipWriter

• String#inspect

• Regexp#inspect

While strings created from these locations will have this encoding, the encoding may not be valid. Be sure to check String#valid_encoding?.

File data written to disk will be transcoded to the default external encoding when written, if default_internal is not nil.

The default external encoding is initialized by the -E option. If -E isn’t set, it is initialized to UTF-8 on Windows and the locale on other operating systems.

Sets default external encoding. You should not set Encoding::default_external in ruby code as strings created before changing the value may have a different encoding from strings created after the value was changed., instead you should use ruby -E to invoke ruby with the correct default_external.

See Encoding::default_external for information on how the default external encoding is used.

Returns default internal encoding. Strings will be transcoded to the default internal encoding in the following places if the default internal encoding is not nil:

• CSV

• Etc.sysconfdir and Etc.systmpdir

• File data read from disk

• File names from Dir

• Integer#chr

• String#inspect and Regexp#inspect

• Strings returned from Readline

• Strings returned from SDBM

• Time#zone

• Values from ENV

• Values in ARGV including $PROGRAM_NAME

Additionally String#encode and String#encode! use the default internal encoding if no encoding is given.

The script encoding (__ENCODING__), not default_internal, is used as the encoding of created strings.

Encoding::default_internal is initialized with -E option or nil otherwise.

Sets default internal encoding or removes default internal encoding when passed nil. You should not set Encoding::default_internal in ruby code as strings created before changing the value may have a different encoding from strings created after the change. Instead you should use ruby -E to invoke ruby with the correct default_internal.

See Encoding::default_internal for information on how the default internal encoding is used.

Returns the locale charmap name. It returns nil if no appropriate information.

Debian GNU/Linux
  LANG=C
    Encoding.locale_charmap  #=> "ANSI_X3.4-1968"
  LANG=ja_JP.EUC-JP
    Encoding.locale_charmap  #=> "EUC-JP"

SunOS 5
  LANG=C
    Encoding.locale_charmap  #=> "646"
  LANG=ja
    Encoding.locale_charmap  #=> "eucJP"

The result is highly platform dependent. So Encoding.find(Encoding.locale_charmap) may cause an error. If you need some encoding object even for unknown locale, Encoding.find(“locale”) can be used.

Returns the message string with enhancements:

• Includes the exception class name in the first line.

• If the value of keyword highlight is true, includes bolding and underlining ANSI codes (see below) to enhance the appearance of the message.

Examples:

begin
  1 / 0
rescue => x
  p x.message
  p x.detailed_message                  # Class name added.
  p x.detailed_message(highlight: true) # Class name, bolding, and underlining added.
end

Output:

"divided by 0"
"divided by 0 (ZeroDivisionError)"
"\e[1mdivided by 0 (\e[1;4mZeroDivisionError\e[m\e[1m)\e[m"

This method is overridden by some gems in the Ruby standard library to add information:

• DidYouMean::Correctable#detailed_message.

• ErrorHighlight::CoreExt#detailed_message.

• SyntaxSuggest#detailed_message.

An overriding method must be tolerant of passed keyword arguments, which may include (but may not be limited to):

• :highlight.

• :did_you_mean.

• :error_highlight.

• :syntax_suggest.

An overriding method should also be careful with ANSI code enhancements; see Messages.

Returns an enhanced message string:

• Includes the exception class name.

• If the value of keyword highlight is true (not nil or false), includes bolding ANSI codes (see below) to enhance the appearance of the message.

• Includes the backtrace:

  • If the value of keyword order is :top (the default), lists the error message and the innermost backtrace entry first.

  • If the value of keyword order is :bottom, lists the error message the the innermost entry last.

Example:

def baz
  begin
    1 / 0
  rescue => x
    pp x.message
    pp x.full_message(highlight: false).split("\n")
    pp x.full_message.split("\n")
  end
end
def bar; baz; end
def foo; bar; end
foo

Output:

"divided by 0"
["t.rb:3:in 'Integer#/': divided by 0 (ZeroDivisionError)",
 "\tfrom t.rb:3:in 'Object#baz'",
 "\tfrom t.rb:10:in 'Object#bar'",
 "\tfrom t.rb:11:in 'Object#foo'",
 "\tfrom t.rb:12:in '<main>'"]
["t.rb:3:in 'Integer#/': \e[1mdivided by 0 (\e[1;4mZeroDivisionError\e[m\e[1m)\e[m",
 "\tfrom t.rb:3:in 'Object#baz'",
 "\tfrom t.rb:10:in 'Object#bar'",
 "\tfrom t.rb:11:in 'Object#foo'",
 "\tfrom t.rb:12:in '<main>'"]

An overriding method should be careful with ANSI code enhancements; see backtrace.

Returns the backtrace (the list of code locations that led to the exception), as an array of Thread::Backtrace::Location instances.

Example (assuming the code is stored in the file named t.rb):

def division(numerator, denominator)
  numerator / denominator
end

begin
  division(1, 0)
rescue => ex
  p ex.backtrace_locations
  # ["t.rb:2:in 'Integer#/'", "t.rb:2:in 'Object#division'", "t.rb:6:in '<main>'"]
  loc = ex.backtrace_locations.first
  p loc.class
  # Thread::Backtrace::Location
  p loc.path
  # "t.rb"
  p loc.lineno
  # 2
  p loc.label
  # "Integer#/"
end

The value returned by this method might be adjusted when raising (see Kernel#raise), or during intermediate handling by set_backtrace.

See also backtrace that provide the same value as an array of strings. (Note though that two values might not be consistent with each other when backtraces are manually adjusted.)

See Backtraces.

Return a list of the local variable names defined where this NameError exception was raised.

Internal use only.

Creates instance variables and corresponding methods that return the value of each instance variable. Equivalent to calling “attr:name” on each name in turn. String arguments are converted to symbols. Returns an array of defined method names as symbols.

Creates an accessor method to allow assignment to the attribute symbol.id2name. String arguments are converted to symbols. Returns an array of defined method names as symbols.

Checks for a constant with the given name in mod. If inherit is set, the lookup will also search the ancestors (and Object if mod is a Module).

The value of the constant is returned if a definition is found, otherwise a NameError is raised.

Math.const_get(:PI)   #=> 3.14159265358979

This method will recursively look up constant names if a namespaced class name is provided. For example:

module Foo; class Bar; end end
Object.const_get 'Foo::Bar'

The inherit flag is respected on each lookup. For example:

module Foo
  class Bar
    VAL = 10
  end

  class Baz < Bar; end
end

Object.const_get 'Foo::Baz::VAL'         # => 10
Object.const_get 'Foo::Baz::VAL', false  # => NameError

If the argument is not a valid constant name a NameError will be raised with a warning “wrong constant name”.

Object.const_get 'foobar' #=> NameError: wrong constant name foobar

Create an HTTP header block as a string.

Includes the empty line that ends the header block.

content_type_string

If this form is used, this string is the Content-Type

headers_hash

A Hash of header values. The following header keys are recognized:

type

The Content-Type header. Defaults to “text/html”

charset

The charset of the body, appended to the Content-Type header.

nph

A boolean value. If true, prepend protocol string and status code, and date; and sets default values for “server” and “connection” if not explicitly set.

status

The HTTP status code as a String, returned as the Status header. The values are:

OK

200 OK

PARTIAL_CONTENT

206 Partial Content

MULTIPLE_CHOICES

300 Multiple Choices

MOVED

301 Moved Permanently

REDIRECT

302 Found

NOT_MODIFIED

304 Not Modified

BAD_REQUEST

400 Bad Request

AUTH_REQUIRED

401 Authorization Required

FORBIDDEN

403 Forbidden

NOT_FOUND

404 Not Found

METHOD_NOT_ALLOWED

405 Method Not Allowed

NOT_ACCEPTABLE

406 Not Acceptable

LENGTH_REQUIRED

411 Length Required

PRECONDITION_FAILED

412 Precondition Failed

SERVER_ERROR

500 Internal Server Error

NOT_IMPLEMENTED

501 Method Not Implemented

BAD_GATEWAY

502 Bad Gateway

VARIANT_ALSO_VARIES

506 Variant Also Negotiates

server

The server software, returned as the Server header.

connection

The connection type, returned as the Connection header (for instance, “close”.

length

The length of the content that will be sent, returned as the Content-Length header.

language

The language of the content, returned as the Content-Language header.

expires

The time on which the current content expires, as a Time object, returned as the Expires header.

cookie

A cookie or cookies, returned as one or more Set-Cookie headers. The value can be the literal string of the cookie; a CGI::Cookie object; an Array of literal cookie strings or Cookie objects; or a hash all of whose values are literal cookie strings or Cookie objects.

These cookies are in addition to the cookies held in the @output_cookies field.

Other headers can also be set; they are appended as key: value.

Examples:

http_header
  # Content-Type: text/html

http_header("text/plain")
  # Content-Type: text/plain

http_header("nph"        => true,
            "status"     => "OK",  # == "200 OK"
              # "status"     => "200 GOOD",
            "server"     => ENV['SERVER_SOFTWARE'],
            "connection" => "close",
            "type"       => "text/html",
            "charset"    => "iso-2022-jp",
              # Content-Type: text/html; charset=iso-2022-jp
            "length"     => 103,
            "language"   => "ja",
            "expires"    => Time.now + 30,
            "cookie"     => [cookie1, cookie2],
            "my_header1" => "my_value",
            "my_header2" => "my_value")

This method does not perform charset conversion.

Returns true if the arguments define a valid commercial date, false otherwise:

Date.valid_commercial?(2001, 5, 6) # => true
Date.valid_commercial?(2001, 5, 8) # => false

See Date.commercial.

See argument start.

Related: Date.jd, Date.commercial.

Erases the line at the cursor corresponding to mode. mode may be either: 0: after cursor 1: before and cursor 2: entire line

You must require ‘io/console’ to use this method.

Erases the screen at the cursor corresponding to mode. mode may be either: 0: after cursor 1: before and cursor 2: entire screen

You must require ‘io/console’ to use this method.

Attempts to convert object into an IO object via method to_io; returns the new IO object if successful, or nil otherwise:

IO.try_convert(STDOUT)   # => #<IO:<STDOUT>>
IO.try_convert(ARGF)     # => #<IO:<STDIN>>
IO.try_convert('STDOUT') # => nil

Closes the stream for reading if open for reading; returns nil. See Open and Closed Streams.

If the stream was opened by IO.popen and is also closed for writing, sets global variable $? (child exit status).

Example:

IO.popen('ruby', 'r+') do |pipe|
  puts pipe.closed?
  pipe.close_write
  puts pipe.closed?
  pipe.close_read
  puts $?
  puts pipe.closed?
end

Output:

false
false
pid 14748 exit 0
true

Related: IO#close, IO#close_write, IO#closed?.

Closes the stream for writing if open for writing; returns nil. See Open and Closed Streams.

Flushes any buffered writes to the operating system before closing.

If the stream was opened by IO.popen and is also closed for reading, sets global variable $? (child exit status).

IO.popen('ruby', 'r+') do |pipe|
  puts pipe.closed?
  pipe.close_read
  puts pipe.closed?
  pipe.close_write
  puts $?
  puts pipe.closed?
end

Output:

false
false
pid 15044 exit 0
true

Related: IO#close, IO#close_read, IO#closed?.