Module: Sass::Util

Extended by:
Util
Included in:
Util
Defined in:
lib/sass/util.rb,
lib/sass/util/test.rb,
lib/sass/util/subset_map.rb,
lib/sass/util/normalized_map.rb

Overview

A module containing various useful functions.

Defined Under Namespace

Modules: Test Classes: MultibyteStringScanner, NormalizedMap, StaticConditionalContext, SubsetMap

Constant Summary collapse

RUBY_VERSION_COMPONENTS =

An array of ints representing the Ruby version number.

RUBY_VERSION.split(".").map {|s| s.to_i}
RUBY_ENGINE =

The Ruby engine we're running under. Defaults to "ruby" if the top-level constant is undefined.

defined?(::RUBY_ENGINE) ? ::RUBY_ENGINE : "ruby"
CHARSET_REGEXP =
/\A@charset "([^"]+)"/
UTF_8_BOM =
bom.encode("UTF-8").force_encoding('BINARY')
UTF_16BE_BOM =
bom.encode("UTF-16BE").force_encoding('BINARY')
UTF_16LE_BOM =
bom.encode("UTF-16LE").force_encoding('BINARY')
VLQ_BASE_SHIFT =
5
VLQ_BASE =
1 << VLQ_BASE_SHIFT
VLQ_BASE_MASK =
VLQ_BASE - 1
VLQ_CONTINUATION_BIT =
VLQ_BASE
BASE64_DIGITS =
('A'..'Z').to_a + ('a'..'z').to_a + ('0'..'9').to_a + ['+', '/']
BASE64_DIGIT_MAP =
begin
  map = {}
  BASE64_DIGITS.each_with_index.map do |digit, i|
    map[digit] = i
  end
  map
end

Instance Method Summary collapse

Instance Method Details

#abstract(obj)

Throws a NotImplementedError for an abstract method.

Parameters:

  • obj (Object)

    self

Raises:

  • (NotImplementedError)


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# File 'lib/sass/util.rb', line 442

def abstract(obj)
  raise NotImplementedError.new("#{obj.class} must implement ##{caller_info[2]}")
end

#ap_geq?(version) ⇒ Boolean

Returns whether this environment is using ActionPack of a version greater than or equal to that specified.

Parameters:

  • version (String)

    The string version number to check against. Should be greater than or equal to Rails 3, because otherwise ActionPack::VERSION isn't autoloaded

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 516

def ap_geq?(version)
  # The ActionPack module is always loaded automatically in Rails >= 3
  return false unless defined?(ActionPack) && defined?(ActionPack::VERSION) &&
    defined?(ActionPack::VERSION::STRING)

  version_geq(ActionPack::VERSION::STRING, version)
end

#ap_geq_3?Boolean

Returns whether this environment is using ActionPack version 3.0.0 or greater.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 505

def ap_geq_3?
  ap_geq?("3.0.0.beta1")
end

#array_minus(minuend, subtrahend) ⇒ Array

Returns a sub-array of minuend containing only elements that are also in subtrahend. Ensures that the return value has the same order as minuend, even on Rubinius where that's not guaranteed by Array#-.

Parameters:

  • minuend (Array)
  • subtrahend (Array)

Returns:

  • (Array)


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# File 'lib/sass/util.rb', line 315

def array_minus(minuend, subtrahend)
  return minuend - subtrahend unless rbx?
  set = Set.new(minuend) - subtrahend
  minuend.select {|e| set.include?(e)}
end

#atomic_create_and_write_file(filename, perms = 0666) {|tmpfile| ... }

This creates a temp file and yields it for writing. When the write is complete, the file is moved into the desired location. The atomicity of this operation is provided by the filesystem's rename operation.

Parameters:

  • filename (String)

    The file to write to.

  • perms (Integer) (defaults to: 0666)

    The permissions used for creating this file. Will be masked by the process umask. Defaults to readable/writeable by all users however the umask usually changes this to only be writable by the process's user.

Yield Parameters:

  • tmpfile (Tempfile)

    The temp file that can be written to.

Returns:

  • The value returned by the block.



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# File 'lib/sass/util.rb', line 1005

def atomic_create_and_write_file(filename, perms = 0666)
  require 'tempfile'
  tmpfile = Tempfile.new(File.basename(filename), File.dirname(filename))
  tmpfile.binmode if tmpfile.respond_to?(:binmode)
  result = yield tmpfile
  tmpfile.close
  ATOMIC_WRITE_MUTEX.synchronize do
    begin
      File.chmod(perms & ~File.umask, tmpfile.path)
    rescue Errno::EPERM
      # If we don't have permissions to chmod the file, don't let that crash
      # the compilation. See issue 1215.
    end
    File.rename tmpfile.path, filename
  end
  result
ensure
  # close and remove the tempfile if it still exists,
  # presumably due to an error during write
  tmpfile.close if tmpfile
  tmpfile.unlink if tmpfile
end

#av_template_class(name)

Returns an ActionView::Template* class. In pre-3.0 versions of Rails, most of these classes were of the form ActionView::TemplateFoo, while afterwards they were of the form ActionView;:Template::Foo.

Parameters:

  • name (#to_s)

    The name of the class to get. For example, :Error will return ActionView::TemplateError or ActionView::Template::Error.



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# File 'lib/sass/util.rb', line 532

def av_template_class(name)
  return ActionView.const_get("Template#{name}") if ActionView.const_defined?("Template#{name}")
  ActionView::Template.const_get(name.to_s)
end

#caller_info(entry = nil) ⇒ [String, Integer, (String, nil)]

Returns information about the caller of the previous method.

Parameters:

  • entry (String) (defaults to: nil)

    An entry in the #caller list, or a similarly formatted string

Returns:

  • ([String, Integer, (String, nil)])

    An array containing the filename, line, and method name of the caller. The method name may be nil



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# File 'lib/sass/util.rb', line 390

def caller_info(entry = nil)
  # JRuby evaluates `caller` incorrectly when it's in an actual default argument.
  entry ||= caller[1]
  info = entry.scan(/^((?:[A-Za-z]:)?.*?):(-?.*?)(?::.*`(.+)')?$/).first
  info[1] = info[1].to_i
  # This is added by Rubinius to designate a block, but we don't care about it.
  info[2].sub!(/ \{\}\Z/, '') if info[2]
  info
end

#check_range(name, range, value, unit = '') ⇒ Numeric

Asserts that value falls within range (inclusive), leaving room for slight floating-point errors.

Parameters:

  • name (String)

    The name of the value. Used in the error message.

  • range (Range)

    The allowed range of values.

  • value (Numeric, Sass::Script::Value::Number)

    The value to check.

  • unit (String) (defaults to: '')

    The unit of the value. Used in error reporting.

Returns:

  • (Numeric)

    value adjusted to fall within range, if it was outside by a floating-point margin.

Raises:

  • (ArgumentError)


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# File 'lib/sass/util.rb', line 356

def check_range(name, range, value, unit = '')
  grace = (-0.00001..0.00001)
  str = value.to_s
  value = value.value if value.is_a?(Sass::Script::Value::Number)
  return value if range.include?(value)
  return range.first if grace.include?(value - range.first)
  return range.last if grace.include?(value - range.last)
  raise ArgumentError.new(
    "#{name} #{str} must be between #{range.first}#{unit} and #{range.last}#{unit}")
end

#check_sass_encoding(str) ⇒ (String, Encoding)

Like #check_encoding, but also checks for a @charset declaration at the beginning of the file and uses that encoding if it exists.

Sass follows CSS's decoding rules.

Parameters:

  • str (String)

    The string of which to check the encoding

Returns:

  • ((String, Encoding))

    The original string encoded as UTF-8, and the source encoding of the string

Raises:

  • (Encoding::UndefinedConversionError)

    if the source encoding cannot be converted to UTF-8

  • (ArgumentError)

    if the document uses an unknown encoding with @charset

  • (Sass::SyntaxError)

    If the document declares an encoding that doesn't match its contents, or it doesn't declare an encoding and its contents are invalid in the native encoding.



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# File 'lib/sass/util.rb', line 737

def check_sass_encoding(str)
  # Determine the fallback encoding following section 3.2 of CSS Syntax Level 3 and Encodings:
  # http://www.w3.org/TR/2013/WD-css-syntax-3-20130919/#determine-the-fallback-encoding
  # http://encoding.spec.whatwg.org/#decode
  binary = str.dup.force_encoding("BINARY")
  if binary.start_with?(UTF_8_BOM)
    binary.slice! 0, UTF_8_BOM.length
    str = binary.force_encoding('UTF-8')
  elsif binary.start_with?(UTF_16BE_BOM)
    binary.slice! 0, UTF_16BE_BOM.length
    str = binary.force_encoding('UTF-16BE')
  elsif binary.start_with?(UTF_16LE_BOM)
    binary.slice! 0, UTF_16LE_BOM.length
    str = binary.force_encoding('UTF-16LE')
  elsif binary =~ CHARSET_REGEXP
    charset = $1.force_encoding('US-ASCII')
    encoding = Encoding.find(charset)
    if encoding.name == 'UTF-16' || encoding.name == 'UTF-16BE'
      encoding = Encoding.find('UTF-8')
    end
    str = binary.force_encoding(encoding)
  elsif str.encoding.name == "ASCII-8BIT"
    # Normally we want to fall back on believing the Ruby string
    # encoding, but if that's just binary we want to make sure
    # it's valid UTF-8.
    str = str.force_encoding('utf-8')
  end

  find_encoding_error(str) unless str.valid_encoding?

  begin
    # If the string is valid, preprocess it according to section 3.3 of CSS Syntax Level 3.
    return str.encode("UTF-8").gsub(/\r\n?|\f/, "\n").tr("\u0000", "�"), str.encoding
  rescue EncodingError
    find_encoding_error(str)
  end
end

#cleanpath(path) ⇒ Pathname

Like Pathname#cleanpath, but normalizes Windows paths to always use backslash separators. Normally, Pathname#cleanpath actually does the reverse -- it will convert backslashes to forward slashes, which can break Pathname#relative_path_from.

Parameters:

  • path (String, Pathname)

Returns:

  • (Pathname)


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# File 'lib/sass/util.rb', line 613

def cleanpath(path)
  path = Pathname.new(path) unless path.is_a?(Pathname)
  pathname(path.cleanpath.to_s)
end

#deprecated(obj, message = nil)

Prints a deprecation warning for the caller method.

Parameters:

  • obj (Object)

    self

  • message (String) (defaults to: nil)

    A message describing what to do instead.



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# File 'lib/sass/util.rb', line 450

def deprecated(obj, message = nil)
  obj_class = obj.is_a?(Class) ? "#{obj}." : "#{obj.class}#"
  full_message = "DEPRECATION WARNING: #{obj_class}#{caller_info[2]} " +
    "will be removed in a future version of Sass.#{("\n" + message) if message}"
  Sass::Util.sass_warn full_message
end

#destructure(val) ⇒ Object

Prepare a value for a destructuring assignment (e.g. a, b = val). This works around a performance bug when using ActiveSupport, and only needs to be called when val is likely to be nil reasonably often.

See this bug report.

Parameters:

  • val (Object)

Returns:

  • (Object)


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# File 'lib/sass/util.rb', line 698

def destructure(val)
  val || []
end

#downcase(string)

Like String.downcase, but only ever downcases ASCII letters.



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# File 'lib/sass/util.rb', line 303

def downcase(string)
  return string.downcase unless ruby2_4?
  string.downcase(:ascii)
end

#encode_vlq(value) ⇒ String

Encodes value as VLQ (http://en.wikipedia.org/wiki/VLQ).

Parameters:

  • value (Integer)

Returns:

  • (String)

    The encoded value



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# File 'lib/sass/util.rb', line 952

def encode_vlq(value)
  if value < 0
    value = ((-value) << 1) | 1
  else
    value <<= 1
  end

  result = ''
  begin
    digit = value & VLQ_BASE_MASK
    value >>= VLQ_BASE_SHIFT
    if value > 0
      digit |= VLQ_CONTINUATION_BIT
    end
    result << BASE64_DIGITS[digit]
  end while value > 0
  result
end

#extract!(array) {|el| ... } ⇒ Array

Destructively removes all elements from an array that match a block, and returns the removed elements.

Parameters:

  • array (Array)

    The array from which to remove elements.

Yields:

  • (el)

    Called for each element.

Yield Parameters:

  • el (*)

    The element to test.

Yield Returns:

  • (Boolean)

    Whether or not to extract the element.

Returns:

  • (Array)

    The extracted elements.



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# File 'lib/sass/util.rb', line 783

def extract!(array)
  out = []
  array.reject! do |e|
    next false unless yield e
    out << e
    true
  end
  out
end

#extract_values(arr) ⇒ (String, Array)

Extracts the non-string vlaues from an array containing both strings and non-strings. These values are replaced with escape sequences. This can be undone using #inject_values.

This is useful e.g. when we want to do string manipulation on an interpolated string.

The precise format of the resulting string is not guaranteed. However, it is guaranteed that newlines and whitespace won't be affected.

Parameters:

  • arr (Array)

    The array from which values are extracted.

Returns:

  • ((String, Array))

    The resulting string, and an array of extracted values.



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# File 'lib/sass/util.rb', line 837

def extract_values(arr)
  values = []
  mapped = arr.map do |e|
    next e.gsub('{', '{{') if e.is_a?(String)
    values << e
    next "{#{values.count - 1}}"
  end
  return mapped.join, values
end

#file_uri_from_path(path) ⇒ String

Converts path to a "file:" URI. This handles Windows paths correctly.

Parameters:

  • path (String, Pathname)

Returns:

  • (String)


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# File 'lib/sass/util.rb', line 664

def file_uri_from_path(path)
  path = path.to_s if path.is_a?(Pathname)
  path = path.tr('\\', '/') if windows?
  path = URI::DEFAULT_PARSER.escape(path)
  return path.start_with?('/') ? "file://" + path : path unless windows?
  return "file:///" + path.tr("\\", "/") if path =~ %r{^[a-zA-Z]:[/\\]}
  return "file:" + path.tr("\\", "/") if path =~ %r{\\\\[^\\]+\\[^\\/]+}
  path.tr("\\", "/")
end

#flatten_vertically(arrs) ⇒ Array

Flattens the first level of nested arrays in arrs. Unlike Array#flatten, this orders the result by taking the first values from each array in order, then the second, and so on.

Parameters:

  • arrs (Array)

    The array to flatten.

Returns:

  • (Array)

    The flattened array.



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# File 'lib/sass/util.rb', line 799

def flatten_vertically(arrs)
  result = []
  arrs = arrs.map {|sub| sub.is_a?(Array) ? sub.dup : Array(sub)}
  until arrs.empty?
    arrs.reject! do |arr|
      result << arr.shift
      arr.empty?
    end
  end
  result
end

#glob(path)

Like Dir.glob, but works with backslash-separated paths on Windows.

Parameters:

  • path (String)


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# File 'lib/sass/util.rb', line 584

def glob(path)
  path = path.tr('\\', '/') if windows?
  if block_given?
    Dir.glob(path) {|f| yield(f)}
  else
    Dir.glob(path)
  end
end

#inject_values(str, values) ⇒ Array

Undoes #extract_values by transforming a string with escape sequences into an array of strings and non-string values.

Parameters:

  • str (String)

    The string with escape sequences.

  • values (Array)

    The array of values to inject.

Returns:

  • (Array)

    The array of strings and values.



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# File 'lib/sass/util.rb', line 853

def inject_values(str, values)
  return [str.gsub('{{', '{')] if values.empty?
  # Add an extra { so that we process the tail end of the string
  result = (str + '{{').scan(/(.*?)(?:(\{\{)|\{(\d+)\})/m).map do |(pre, esc, n)|
    [pre, esc ? '{' : '', n ? values[n.to_i] : '']
  end.flatten(1)
  result[-2] = '' # Get rid of the extra {
  merge_adjacent_strings(result).reject {|s| s == ''}
end

#inspect_obj(obj) ⇒ String

Like Object#inspect, but preserves non-ASCII characters rather than escaping them under Ruby 1.9.2. This is necessary so that the precompiled Haml template can be #encoded into @options[:encoding] before being evaluated.

Parameters:

  • obj (Object)

Returns:

  • (String)


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# File 'lib/sass/util.rb', line 818

def inspect_obj(obj)
  return obj.inspect unless version_geq(RUBY_VERSION, "1.9.2")
  return ':' + inspect_obj(obj.to_s) if obj.is_a?(Symbol)
  return obj.inspect unless obj.is_a?(String)
  '"' + obj.gsub(/[\x00-\x7F]+/) {|s| s.inspect[1...-1]} + '"'
end

#intersperse(enum, val) ⇒ Array

Intersperses a value in an enumerable, as would be done with Array#join but without concatenating the array together afterwards.

Parameters:

  • enum (Enumerable)
  • val

Returns:

  • (Array)


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# File 'lib/sass/util.rb', line 215

def intersperse(enum, val)
  enum.inject([]) {|a, e| a << e << val}[0...-1]
end

#ironruby?Boolean

Whether or not this is running on IronRuby.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 553

def ironruby?
  return @ironruby if defined?(@ironruby)
  @ironruby = RUBY_ENGINE == "ironruby"
end

#jruby?Boolean

Whether or not this is running on JRuby.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 569

def jruby?
  return @jruby if defined?(@jruby)
  @jruby = RUBY_PLATFORM =~ /java/
end

#jruby_versionArray<Integer>

Returns an array of ints representing the JRuby version number.

Returns:

  • (Array<Integer>)


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# File 'lib/sass/util.rb', line 577

def jruby_version
  @jruby_version ||= ::JRUBY_VERSION.split(".").map {|s| s.to_i}
end

#json_escape_string(s) ⇒ String

Escapes certain characters so that the result can be used as the JSON string value. Returns the original string if no escaping is necessary.

Parameters:

  • s (String)

    The string to be escaped

Returns:

  • (String)

    The escaped string



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# File 'lib/sass/util.rb', line 891

def json_escape_string(s)
  return s if s !~ /["\\\b\f\n\r\t]/

  result = ""
  s.split("").each do |c|
    case c
    when '"', "\\"
      result << "\\" << c
    when "\n" then result << "\\n"
    when "\t" then result << "\\t"
    when "\r" then result << "\\r"
    when "\f" then result << "\\f"
    when "\b" then result << "\\b"
    else
      result << c
    end
  end
  result
end

#json_value_of(v) ⇒ String

Converts the argument into a valid JSON value.

Parameters:

  • v (Integer, String, Array, Boolean, nil)

Returns:

  • (String)


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# File 'lib/sass/util.rb', line 915

def json_value_of(v)
  case v
  when Integer
    v.to_s
  when String
    "\"" + json_escape_string(v) + "\""
  when Array
    "[" + v.map {|x| json_value_of(x)}.join(",") + "]"
  when NilClass
    "null"
  when TrueClass
    "true"
  when FalseClass
    "false"
  else
    raise ArgumentError.new("Unknown type: #{v.class.name}")
  end
end

#lcs(x, y) {|a, b| ... } ⇒ Array

Computes a single longest common subsequence for x and y. If there are more than one longest common subsequences, the one returned is that which starts first in x.

Parameters:

  • x (Array)
  • y (Array)

Yields:

  • (a, b)

    An optional block to use in place of a check for equality between elements of x and y.

Yield Returns:

  • (Object, nil)

    If the two values register as equal, this will return the value to use in the LCS array.

Returns:

  • (Array)

    The LCS



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# File 'lib/sass/util.rb', line 289

def lcs(x, y, &block)
  x = [nil, *x]
  y = [nil, *y]
  block ||= proc {|a, b| a == b && a}
  lcs_backtrace(lcs_table(x, y, &block), x, y, x.size - 1, y.size - 1, &block)
end

#map_hash(hash) {|key, value| ... } ⇒ Hash

Maps the key-value pairs of a hash according to a block.

Examples:

map_hash({:foo => "bar", :baz => "bang"}) {|k, v| [k.to_s, v.to_sym]}
  #=> {"foo" => :bar, "baz" => :bang}

Parameters:

  • hash (Hash)

    The hash to map

Yields:

  • (key, value)

    A block in which the key-value pairs are transformed

Yield Parameters:

  • The (key)

    hash key

  • The (value)

    hash value

Yield Returns:

  • ((Object, Object))

    The new value for the [key, value] pair

Returns:

  • (Hash)

    The mapped hash

See Also:



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# File 'lib/sass/util.rb', line 88

def map_hash(hash)
  # Copy and modify is more performant than mapping to an array and using
  # to_hash on the result.
  rv = hash.class.new
  hash.each do |k, v|
    new_key, new_value = yield(k, v)
    new_key = hash.denormalize(new_key) if hash.is_a?(NormalizedMap) && new_key == k
    rv[new_key] = new_value
  end
  rv
end

#map_keys(hash) {|key| ... } ⇒ Hash

Maps the keys in a hash according to a block.

Examples:

map_keys({:foo => "bar", :baz => "bang"}) {|k| k.to_s}
  #=> {"foo" => "bar", "baz" => "bang"}

Parameters:

  • hash (Hash)

    The hash to map

Yields:

  • (key)

    A block in which the keys are transformed

Yield Parameters:

  • key (Object)

    The key that should be mapped

Yield Returns:

  • (Object)

    The new value for the key

Returns:

  • (Hash)

    The mapped hash

See Also:



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# File 'lib/sass/util.rb', line 48

def map_keys(hash)
  map_hash(hash) {|k, v| [yield(k), v]}
end

#map_vals(hash) {|value| ... } ⇒ Hash

Maps the values in a hash according to a block.

Examples:

map_values({:foo => "bar", :baz => "bang"}) {|v| v.to_sym}
  #=> {:foo => :bar, :baz => :bang}

Parameters:

  • hash (Hash)

    The hash to map

Yields:

  • (value)

    A block in which the values are transformed

Yield Parameters:

  • value (Object)

    The value that should be mapped

Yield Returns:

  • (Object)

    The new value for the value

Returns:

  • (Hash)

    The mapped hash

See Also:



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# File 'lib/sass/util.rb', line 64

def map_vals(hash)
  # We don't delegate to map_hash for performance here
  # because map_hash does more than is necessary.
  rv = hash.class.new
  hash = hash.as_stored if hash.is_a?(NormalizedMap)
  hash.each do |k, v|
    rv[k] = yield(v)
  end
  rv
end

#max(val1, val2)

Returns the maximum of val1 and val2. We use this over Array.max to avoid unnecessary garbage collection.



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# File 'lib/sass/util.rb', line 323

def max(val1, val2)
  val1 > val2 ? val1 : val2
end

#merge_adjacent_strings(arr) ⇒ Array

Concatenates all strings that are adjacent in an array, while leaving other elements as they are.

Examples:

merge_adjacent_strings([1, "foo", "bar", 2, "baz"])
  #=> [1, "foobar", 2, "baz"]

Parameters:

  • arr (Array)

Returns:

  • (Array)

    The enumerable with strings merged



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# File 'lib/sass/util.rb', line 155

def merge_adjacent_strings(arr)
  # Optimize for the common case of one element
  return arr if arr.size < 2
  arr.inject([]) do |a, e|
    if e.is_a?(String)
      if a.last.is_a?(String)
        a.last << e
      else
        a << e.dup
      end
    else
      a << e
    end
    a
  end
end

#min(val1, val2)

Returns the minimum of val1 and val2. We use this over Array.min to avoid unnecessary garbage collection.



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# File 'lib/sass/util.rb', line 329

def min(val1, val2)
  val1 <= val2 ? val1 : val2
end

#pathname(path) ⇒ Pathname

Like Pathname.new, but normalizes Windows paths to always use backslash separators.

Pathname#relative_path_from can break if the two pathnames aren't consistent in their slash style.

Parameters:

  • path (String)

Returns:

  • (Pathname)


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# File 'lib/sass/util.rb', line 601

def pathname(path)
  path = path.tr("/", "\\") if windows?
  Pathname.new(path)
end

#paths(arrs) ⇒ Array<Arrays>

Return an array of all possible paths through the given arrays.

Examples:

paths([[1, 2], [3, 4], [5]]) #=>
  # [[1, 3, 5],
  #  [2, 3, 5],
  #  [1, 4, 5],
  #  [2, 4, 5]]

Parameters:

  • arrs (Array<Array>)

Returns:

  • (Array<Arrays>)


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# File 'lib/sass/util.rb', line 272

def paths(arrs)
  arrs.inject([[]]) do |paths, arr|
    arr.map {|e| paths.map {|path| path + [e]}}.flatten(1)
  end
end

#powerset(arr) ⇒ Set<Set>

Computes the powerset of the given array. This is the set of all subsets of the array.

Examples:

powerset([1, 2, 3]) #=>
  Set[Set[], Set[1], Set[2], Set[3], Set[1, 2], Set[2, 3], Set[1, 3], Set[1, 2, 3]]

Parameters:

  • arr (Enumerable)

Returns:

  • (Set<Set>)

    The subsets of arr



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# File 'lib/sass/util.rb', line 108

def powerset(arr)
  arr.inject([Set.new].to_set) do |powerset, el|
    new_powerset = Set.new
    powerset.each do |subset|
      new_powerset << subset
      new_powerset << subset + [el]
    end
    new_powerset
  end
end

#rails_envString?

Returns the environment of the Rails application, if this is running in a Rails context. Returns nil if no such environment is defined.

Returns:

  • (String, nil)


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# File 'lib/sass/util.rb', line 495

def rails_env
  return ::Rails.env.to_s if defined?(::Rails.env)
  return RAILS_ENV.to_s if defined?(RAILS_ENV)
  nil
end

#rails_rootString?

Returns the root of the Rails application, if this is running in a Rails context. Returns nil if no such root is defined.

Returns:

  • (String, nil)


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# File 'lib/sass/util.rb', line 481

def rails_root
  if defined?(::Rails.root)
    return ::Rails.root.to_s if ::Rails.root
    raise "ERROR: Rails.root is nil!"
  end
  return RAILS_ROOT.to_s if defined?(RAILS_ROOT)
  nil
end

#rbx?Boolean

Whether or not this is running on Rubinius.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 561

def rbx?
  return @rbx if defined?(@rbx)
  @rbx = RUBY_ENGINE == "rbx"
end

#realpath(path) ⇒ Pathname

Returns path with all symlinks resolved.

Parameters:

  • path (String, Pathname)

Returns:

  • (Pathname)


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# File 'lib/sass/util.rb', line 622

def realpath(path)
  path = Pathname.new(path) unless path.is_a?(Pathname)

  # Explicitly DON'T run #pathname here. We don't want to convert
  # to Windows directory separators because we're comparing these
  # against the paths returned by Listen, which use forward
  # slashes everywhere.
  begin
    path.realpath
  rescue SystemCallError
    # If [path] doesn't actually exist, don't bail, just
    # return the original.
    path
  end
end

#relative_path_from(path, from) ⇒ Pathname?

Returns path relative to from.

This is like Pathname#relative_path_from except it accepts both strings and pathnames, it handles Windows path separators correctly, and it throws an error rather than crashing if the paths use different encodings (https://github.com/ruby/ruby/pull/713).

Parameters:

  • path (String, Pathname)
  • from (String, Pathname)

Returns:

  • (Pathname?)


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# File 'lib/sass/util.rb', line 648

def relative_path_from(path, from)
  pathname(path.to_s).relative_path_from(pathname(from.to_s))
rescue NoMethodError => e
  raise e unless e.name == :zero?

  # Work around https://github.com/ruby/ruby/pull/713.
  path = path.to_s
  from = from.to_s
  raise ArgumentError("Incompatible path encodings: #{path.inspect} is #{path.encoding}, " +
    "#{from.inspect} is #{from.encoding}")
end

#replace_subseq(arr, subseq, replacement) ⇒ Array

Non-destructively replaces all occurrences of a subsequence in an array with another subsequence.

Examples:

replace_subseq([1, 2, 3, 4, 5], [2, 3], [:a, :b])
  #=> [1, :a, :b, 4, 5]

Parameters:

  • arr (Array)

    The array whose subsequences will be replaced.

  • subseq (Array)

    The subsequence to find and replace.

  • replacement (Array)

    The sequence that subseq will be replaced with.

Returns:

  • (Array)

    arr with subseq replaced with replacement.



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# File 'lib/sass/util.rb', line 183

def replace_subseq(arr, subseq, replacement)
  new = []
  matched = []
  i = 0
  arr.each do |elem|
    if elem != subseq[i]
      new.push(*matched)
      matched = []
      i = 0
      new << elem
      next
    end

    if i == subseq.length - 1
      matched = []
      i = 0
      new.push(*replacement)
    else
      matched << elem
      i += 1
    end
  end
  new.push(*matched)
  new
end

#restrict(value, range) ⇒ Numeric

Restricts a number to falling within a given range. Returns the number if it falls within the range, or the closest value in the range if it doesn't.

Parameters:

  • value (Numeric)
  • range (Range<Numeric>)

Returns:

  • (Numeric)


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# File 'lib/sass/util.rb', line 126

def restrict(value, range)
  [[value, range.first].max, range.last].min
end

#retry_on_windows { ... }

Retries a filesystem operation if it fails on Windows. Windows has weird and flaky locking rules that can cause operations to fail.

Yields:

  • [] The filesystem operation.



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# File 'lib/sass/util.rb', line 678

def retry_on_windows
  return yield unless windows?

  begin
    yield
  rescue SystemCallError
    sleep 0.1
    yield
  end
end

#round(value) ⇒ Numeric

Like [Fixnum.round], but leaves rooms for slight floating-point differences.

Parameters:

  • value (Numeric)

Returns:

  • (Numeric)


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# File 'lib/sass/util.rb', line 135

def round(value)
  # If the number is within epsilon of X.5, round up (or down for negative
  # numbers).
  mod = value % 1
  mod_is_half = (mod - 0.5).abs < Script::Value::Number.epsilon
  if value > 0
    !mod_is_half && mod < 0.5 ? value.floor : value.ceil
  else
    mod_is_half || mod < 0.5 ? value.floor : value.ceil
  end
end

#ruby2_4?Boolean

Whether or not this is running under Ruby 2.4 or higher.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 713

def ruby2_4?
  return @ruby2_4 if defined?(@ruby2_4)
  @ruby2_4 =
    if RUBY_VERSION_COMPONENTS[0] == 2
      RUBY_VERSION_COMPONENTS[1] >= 4
    else
      RUBY_VERSION_COMPONENTS[0] > 2
    end
end

#sass_warn(msg)

The same as Kernel#warn, but is silenced by #silence_sass_warnings.

Parameters:

  • msg (String)


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# File 'lib/sass/util.rb', line 470

def sass_warn(msg)
  Sass.logger.warn("#{msg}\n")
end

#scope(file) ⇒ String

Returns the path of a file relative to the Sass root directory.

Parameters:

  • file (String)

    The filename relative to the Sass root

Returns:

  • (String)

    The filename relative to the the working directory



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# File 'lib/sass/util.rb', line 32

def scope(file)
  File.join(Sass::ROOT_DIR, file)
end

#silence_sass_warnings { ... }

Silences all Sass warnings within a block.

Yields:

  • A block in which no Sass warnings will be printed



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# File 'lib/sass/util.rb', line 460

def silence_sass_warnings
  old_level, Sass.logger.log_level = Sass.logger.log_level, :error
  yield
ensure
  Sass.logger.log_level = old_level
end

#slice_by(enum)



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# File 'lib/sass/util.rb', line 219

def slice_by(enum)
  results = []
  enum.each do |value|
    key = yield(value)
    if !results.empty? && results.last.first == key
      results.last.last << value
    else
      results << [key, [value]]
    end
  end
  results
end

#sourcemap_name(css) ⇒ String

Builds a sourcemap file name given the generated CSS file name.

Parameters:

  • css (String)

    The generated CSS file name.

Returns:

  • (String)

    The source map file name.



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# File 'lib/sass/util.rb', line 881

def sourcemap_name(css)
  css + ".map"
end

#strip_string_array(arr) ⇒ Array

Destructively strips whitespace from the beginning and end of the first and last elements, respectively, in the array (if those elements are strings).

Parameters:

  • arr (Array)

Returns:

  • (Array)

    arr



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# File 'lib/sass/util.rb', line 255

def strip_string_array(arr)
  arr.first.lstrip! if arr.first.is_a?(String)
  arr.last.rstrip! if arr.last.is_a?(String)
  arr
end

#subsequence?(seq1, seq2) ⇒ Boolean

Returns whether or not seq1 is a subsequence of seq2. That is, whether or not seq2 contains every element in seq1 in the same order (and possibly more elements besides).

Parameters:

  • seq1 (Array)
  • seq2 (Array)

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 374

def subsequence?(seq1, seq2)
  i = j = 0
  loop do
    return true if i == seq1.size
    return false if j == seq2.size
    i += 1 if seq1[i] == seq2[j]
    j += 1
  end
end

#substitute(ary, from, to)

Substitutes a sub-array of one array with another sub-array.

Parameters:

  • ary (Array)

    The array in which to make the substitution

  • from (Array)

    The sequence of elements to replace with to

  • to (Array)

    The sequence of elements to replace from with



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# File 'lib/sass/util.rb', line 237

def substitute(ary, from, to)
  res = ary.dup
  i = 0
  while i < res.size
    if res[i...i + from.size] == from
      res[i...i + from.size] = to
    end
    i += 1
  end
  res
end

#undefined_conversion_error_char(e) ⇒ String

Returns a string description of the character that caused an Encoding::UndefinedConversionError.

Parameters:

  • e (Encoding::UndefinedConversionError)

Returns:

  • (String)


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# File 'lib/sass/util.rb', line 338

def undefined_conversion_error_char(e)
  # Rubinius (as of 2.0.0.rc1) pre-quotes the error character.
  return e.error_char if rbx?
  # JRuby (as of 1.7.2) doesn't have an error_char field on
  # Encoding::UndefinedConversionError.
  return e.error_char.dump unless jruby?
  e.message[/^"[^"]+"/] # "
end

#upcase(string)

Like String.upcase, but only ever upcases ASCII letters.



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# File 'lib/sass/util.rb', line 297

def upcase(string)
  return string.upcase unless ruby2_4?
  string.upcase(:ascii)
end

#version_geq(v1, v2) ⇒ Boolean

Returns whether one version string represents the same or a more recent version than another.

Parameters:

  • v1 (String)

    A version string.

  • v2 (String)

    Another version string.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 434

def version_geq(v1, v2)
  version_gt(v1, v2) || !version_gt(v2, v1)
end

#version_gt(v1, v2) ⇒ Boolean

Returns whether one version string represents a more recent version than another.

Parameters:

  • v1 (String)

    A version string.

  • v2 (String)

    Another version string.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 405

def version_gt(v1, v2)
  # Construct an array to make sure the shorter version is padded with nil
  Array.new([v1.length, v2.length].max).zip(v1.split("."), v2.split(".")) do |_, p1, p2|
    p1 ||= "0"
    p2 ||= "0"
    release1 = p1 =~ /^[0-9]+$/
    release2 = p2 =~ /^[0-9]+$/
    if release1 && release2
      # Integer comparison if both are full releases
      p1, p2 = p1.to_i, p2.to_i
      next if p1 == p2
      return p1 > p2
    elsif !release1 && !release2
      # String comparison if both are prereleases
      next if p1 == p2
      return p1 > p2
    else
      # If only one is a release, that one is newer
      return release1
    end
  end
end

#windows?Boolean

Whether or not this is running on Windows.

Returns:

  • (Boolean)


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# File 'lib/sass/util.rb', line 545

def windows?
  return @windows if defined?(@windows)
  @windows = (RbConfig::CONFIG['host_os'] =~ /mswin|windows|mingw/i)
end

#with_extracted_values(arr) {|str| ... } ⇒ Array

Allows modifications to be performed on the string form of an array containing both strings and non-strings.

Parameters:

  • arr (Array)

    The array from which values are extracted.

Yields:

  • (str)

    A block in which string manipulation can be done to the array.

Yield Parameters:

  • str (String)

    The string form of arr.

Yield Returns:

  • (String)

    The modified string.

Returns:

  • (Array)

    The modified, interpolated array.



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# File 'lib/sass/util.rb', line 871

def with_extracted_values(arr)
  str, vals = extract_values(arr)
  str = yield str
  inject_values(str, vals)
end