Module: Haml::Util

Extended by:
Util
Included in:
Buffer, Util, Version, Sass::Engine, Sass::Plugin, Sass::Script::Color
Defined in:
lib/haml/util.rb,
lib/haml/util/subset_map.rb

Overview

A module containing various useful functions.

Defined Under Namespace

Classes: StaticConditionalContext, SubsetMap

Constant Summary collapse

RUBY_VERSION =

An array of ints representing the Ruby version number.

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

We could automatically add in any non-ASCII-compatible encodings here, but there's not really a good way to do that without manually checking that each encoding encodes all ASCII characters properly, which takes long enough to affect the startup time of the CLI.

%w[UTF-8 UTF-16BE UTF-16LE UTF-32BE UTF-32LE]
CHARSET_REGEXPS = 
Hash.new do |h, e|
  h[e] =
    begin
      # /\A(?:\uFEFF)?@charset "(.*?)"|\A(\uFEFF)/
      Regexp.new(/\A(?:#{_enc("\uFEFF", e)})?#{
        _enc('@charset "', e)}(.*?)#{_enc('"', e)}|\A(#{
        _enc("\uFEFF", e)})/)
    rescue
      # /\A@charset "(.*?)"/
      Regexp.new(/\A#{_enc('@charset "', e)}(.*?)#{_enc('"', e)}/)
    end
end
@@silence_warnings = 
false

Instance Method Summary collapse

Instance Method Details

#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/haml/util.rb', line 306

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)

  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/haml/util.rb', line 295

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

#assert_html_safe!(text)

Assert that a given object (usually a String) is HTML safe according to Rails' XSS handling, if it's loaded.

Parameters:

  • text (Object)

Raises:



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# File 'lib/haml/util.rb', line 354

def assert_html_safe!(text)
  return unless rails_xss_safe? && text && !text.to_s.html_safe?
  raise Haml::Error.new("Expected #{text.inspect} to be HTML-safe.")
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/haml/util.rb', line 322

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

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

Returns information about the caller of the previous method.

Parameters:

  • entry (String) (defaults to: ) —

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

Returns:

  • ([String, Fixnum, (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/haml/util.rb', line 226

def caller_info(entry = caller[1])
  info = entry.scan(/^(.*?):(-?.*?)(?::.*`(.+)')?$/).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_encoding(str) {|msg| ... } ⇒ String

Checks that the encoding of a string is valid in Ruby 1.9 and cleans up potential encoding gotchas like the UTF-8 BOM. If it's not, yields an error string describing the invalid character and the line on which it occurrs.

Parameters:

  • str (String) —

    The string of which to check the encoding

Yields:

  • (msg) —

    A block in which an encoding error can be raised. Only yields if there is an encoding error

Yield Parameters:

  • msg (String) —

    The error message to be raised

Returns:

  • (String) —

    str, potentially with encoding gotchas like BOMs removed



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# File 'lib/haml/util.rb', line 407

def check_encoding(str)
  if ruby1_8?
    return str.gsub(/\A\xEF\xBB\xBF/, '') # Get rid of the UTF-8 BOM
  elsif str.valid_encoding?
    # Get rid of the Unicode BOM if possible
    if str.encoding.name =~ /^UTF-(8|16|32)(BE|LE)?$/
      return str.gsub(Regexp.new("\\A\uFEFF".encode(str.encoding.name)), '')
    else
      return str
    end
  end

  encoding = str.encoding
  newlines = Regexp.new("\r\n|\r|\n".encode(encoding).force_encoding("binary"))
  str.force_encoding("binary").split(newlines).each_with_index do |line, i|
    begin
      line.encode(encoding)
    rescue Encoding::UndefinedConversionError => e
      yield <<MSG.rstrip, i + 1
Invalid #{encoding.name} character #{e.error_char.dump}
MSG
    end
  end
  return str
end

#check_haml_encoding(str) {|msg| ... } ⇒ String

Like #check_encoding, but also checks for a Ruby-style -# coding: comment at the beginning of the template and uses that encoding if it exists.

The Sass encoding rules are simple. If a -# coding: comment exists, we assume that that's the original encoding of the document. Otherwise, we use whatever encoding Ruby has.

Haml uses the same rules for parsing coding comments as Ruby. This means that it can understand Emacs-style comments (e.g. -*- encoding: "utf-8" -*-), and also that it cannot understand non-ASCII-compatible encodings such as UTF-16 and UTF-32.

Parameters:

  • str (String) —

    The Haml template of which to check the encoding

Yields:

  • (msg) —

    A block in which an encoding error can be raised. Only yields if there is an encoding error

Yield Parameters:

  • msg (String) —

    The error message to be raised

Returns:

  • (String) —

    The original string encoded properly

Raises:

  • (ArgumentError) —

    if the document declares an unknown encoding



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# File 'lib/haml/util.rb', line 453

def check_haml_encoding(str, &block)
  return check_encoding(str, &block) if ruby1_8?
  str = str.dup if str.frozen?

  bom, encoding = parse_haml_magic_comment(str)
  if encoding; str.force_encoding(encoding)
  elsif bom; str.force_encoding("UTF-8")
  end

  return check_encoding(str, &block)
end

#check_sass_encoding(str) {|msg| ... } ⇒ (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.

The Sass encoding rules are simple. If a @charset declaration exists, we assume that that's the original encoding of the document. Otherwise, we use whatever encoding Ruby has. Then we convert that to UTF-8 to process internally. The UTF-8 end result is what's returned by this method.

Parameters:

  • str (String) —

    The string of which to check the encoding

Yields:

  • (msg) —

    A block in which an encoding error can be raised. Only yields if there is an encoding error

Yield Parameters:

  • msg (String) —

    The error message to be raised

Returns:

  • ((String, Encoding)) —

    The original string encoded as UTF-8, and the source encoding of the string (or nil under Ruby 1.8)

Raises:

  • (Encoding::UndefinedConversionError) —

    if the source encoding cannot be converted to UTF-8

  • (ArgumentError) —

    if the document uses an unknown encoding with @charset



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# File 'lib/haml/util.rb', line 484

def check_sass_encoding(str, &block)
  return check_encoding(str, &block), nil if ruby1_8?
  # We allow any printable ASCII characters but double quotes in the charset decl
  bin = str.dup.force_encoding("BINARY")
  encoding = Haml::Util::ENCODINGS_TO_CHECK.find do |enc|
    bin =~ Haml::Util::CHARSET_REGEXPS[enc]
  end
  charset, bom = $1, $2
  if charset
    charset = charset.force_encoding(encoding).encode("UTF-8")
    if endianness = encoding[/[BL]E$/]
      begin
        Encoding.find(charset + endianness)
        charset << endianness
      rescue ArgumentError # Encoding charset + endianness doesn't exist
      end
    end
    str.force_encoding(charset)
  elsif bom
    str.force_encoding(encoding)
  end

  str = check_encoding(str, &block)
  return str.encode("UTF-8"), str.encoding
end

#def_static_method(klass, name, args, *vars, erb)

This is used for methods in Buffer that need to be very fast, and take a lot of boolean parameters that are known at compile-time. Instead of passing the parameters in normally, a separate method is defined for every possible combination of those parameters; these are then called using #static_method_name.

To define a static method, an ERB template for the method is provided. All conditionals based on the static parameters are done as embedded Ruby within this template. For example:

def_static_method(Foo, :my_static_method, [:foo, :bar], :baz, :bang, <<RUBY)
  <% if baz && bang %>
    return foo + bar
  <% elsif baz || bang %>
    return foo - bar
  <% else %>
    return 17
  <% end %>
RUBY

#static_method_name can be used to call static methods.

Parameters:

  • klass (Module) —

    The class on which to define the static method

  • name (#to_s) —

    The (base) name of the static method

  • args (Array<Symbol>) —

    The names of the arguments to the defined methods (not to the ERB template)

  • vars (Array<Symbol>) —

    The names of the static boolean variables to be made available to the ERB template

  • erb (String) —

    The template for the method code



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# File 'lib/haml/util.rb', line 672

def def_static_method(klass, name, args, *vars)
  erb = vars.pop
  info = caller_info
  powerset(vars).each do |set|
    context = StaticConditionalContext.new(set).instance_eval {binding}
    klass.class_eval(<<METHOD, info[0], info[1])
def #{static_method_name(name, *vars.map {|v| set.include?(v)})}(#{args.join(', ')})
  #{ERB.new(erb).result(context)}
end
METHOD
  end
end

#enum_cons(enum, n) ⇒ Enumerator

A version of Enumerable#enum_cons that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

  • n (Fixnum) —

    The size of each cons

Returns:

  • (Enumerator) —

    The consed enumerator



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# File 'lib/haml/util.rb', line 568

def enum_cons(enum, n)
  ruby1_8? ? enum.enum_cons(n) : enum.each_cons(n)
end

#enum_slice(enum, n) ⇒ Enumerator

A version of Enumerable#enum_slice that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

  • n (Fixnum) —

    The size of each slice

Returns:

  • (Enumerator) —

    The consed enumerator



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

def enum_slice(enum, n)
  ruby1_8? ? enum.enum_slice(n) : enum.each_slice(n)
end

#enum_with_index(enum) ⇒ Enumerator

A version of Enumerable#enum_with_index that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

Returns:

  • (Enumerator) —

    The with-index enumerator



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# File 'lib/haml/util.rb', line 559

def enum_with_index(enum)
  ruby1_8? ? enum.enum_with_index : enum.each_with_index
end

#flatten(arr, n) ⇒ Array

Flattens the first n nested arrays in a cross-version manner.

Parameters:

  • arr (Array) —

    The array to flatten

  • n (Fixnum) —

    The number of levels to flatten

Returns:

  • (Array) —

    The flattened array



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# File 'lib/haml/util.rb', line 594

def flatten(arr, n)
  return arr.flatten(n) unless ruby1_8_6?
  return arr if n == 0
  arr.inject([]) {|res, e| e.is_a?(Array) ? res.concat(flatten(e, n - 1)) : res << e}
end

#haml_warn(msg)

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

Parameters:

  • msg (String) 


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# File 'lib/haml/util.rb', line 259

def haml_warn(msg)
  return if @@silence_warnings
  warn(msg)
end

#has?(attr, klass, method) ⇒ Boolean

Checks to see if a class has a given method. For example:

Haml::Util.has?(:public_instance_method, String, :gsub) #=> true

Method collections like Class#instance_methods return strings in Ruby 1.8 and symbols in Ruby 1.9 and on, so this handles checking for them in a compatible way.

Parameters:

  • attr (#to_s) —

    The (singular) name of the method-collection method (e.g. :instance_methods, :private_methods)

  • klass (Module) —

    The class to check the methods of which to check

  • method (String, Symbol) —

    The name of the method do check for

Returns:

  • (Boolean) —

    Whether or not the given collection has the given method



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# File 'lib/haml/util.rb', line 551

def has?(attr, klass, method)
  klass.send("#{attr}s").include?(ruby1_8? ? method.to_s : method.to_sym)
end

#html_safe(text) ⇒ String?

Returns the given text, marked as being HTML-safe. With older versions of the Rails XSS-safety mechanism, this destructively modifies the HTML-safety of text.

Parameters:

  • text (String, nil)

Returns:

  • (String, nil) —

    text, marked as HTML-safe



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# File 'lib/haml/util.rb', line 344

def html_safe(text)
  return unless text
  return text.html_safe if defined?(ActiveSupport::SafeBuffer)
  text.html_safe!
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/haml/util.rb', line 153

def intersperse(enum, val)
  enum.inject([]) {|a, e| a << e << val}[0...-1]
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/haml/util.rb', line 214

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. For example:

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/haml/util.rb', line 88

def map_hash(hash, &block)
  to_hash(hash.map(&block))
end

#map_keys(hash) {|key| ... } ⇒ Hash

Maps the keys in a hash according to a block. For example:

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/haml/util.rb', line 53

def map_keys(hash)
  to_hash(hash.map {|k, v| [yield(k), v]})
end

#map_vals(hash) {|value| ... } ⇒ Hash

Maps the values in a hash according to a block. For example:

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/haml/util.rb', line 70

def map_vals(hash)
  to_hash(hash.map {|k, v| [k, yield(v)]})
end

#merge_adjacent_strings(enum) ⇒ Array

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

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

Parameters:

  • enum (Enumerable)

Returns:

  • (Array) —

    The enumerable with strings merged



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# File 'lib/haml/util.rb', line 132

def merge_adjacent_strings(enum)
  enum.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

#ord(c) ⇒ Fixnum

Returns the ASCII code of the given character.

Parameters:

  • c (String) —

    All characters but the first are ignored.

Returns:

  • (Fixnum) —

    The ASCII code of c.



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# File 'lib/haml/util.rb', line 585

def ord(c)
  ruby1_8? ? c[0] : c.ord
end

#paths(arrs) ⇒ Array<Arrays>

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

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/haml/util.rb', line 197

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

#powerset(arr) ⇒ Set<Set>

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

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/haml/util.rb', line 101

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_env ⇒ String?

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/haml/util.rb', line 285

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

#rails_root ⇒ String?

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/haml/util.rb', line 271

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)
  return nil
end

#rails_safe_buffer_class ⇒ Class

The class for the Rails SafeBuffer XSS protection class. This varies depending on Rails version.

Returns:

  • (Class) 


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# File 'lib/haml/util.rb', line 363

def rails_safe_buffer_class
  # It's important that we check ActiveSupport first,
  # because in Rails 2.3.6 ActionView::SafeBuffer exists
  # but is a deprecated proxy object.
  return ActiveSupport::SafeBuffer if defined?(ActiveSupport::SafeBuffer)
  return ActionView::SafeBuffer
end

#rails_xss_safe? ⇒ Boolean

Whether or not ActionView's XSS protection is available and enabled, as is the default for Rails 3.0+, and optional for version 2.3.5+. Overridden in haml/template.rb if this is the case.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 334

def rails_xss_safe?
  false
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/haml/util.rb', line 119

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

#ruby1_8? ⇒ Boolean

Whether or not this is running under Ruby 1.8 or lower.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 385

def ruby1_8?
  Haml::Util::RUBY_VERSION[0] == 1 && Haml::Util::RUBY_VERSION[1] < 9
end

#ruby1_8_6? ⇒ Boolean

Whether or not this is running under Ruby 1.8.6 or lower. Note that lower versions are not officially supported.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 393

def ruby1_8_6?
  ruby1_8? && Haml::Util::RUBY_VERSION[2] < 7
end

#scope(file) ⇒ String

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

Parameters:

  • file (String) —

    The filename relative to the Haml root

Returns:

  • (String) —

    The filename relative to the the working directory



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# File 'lib/haml/util.rb', line 24

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

#set_eql?(set1, set2) ⇒ Boolean

Tests the hash-equality of two sets in a cross-version manner. Aggravatingly, this is order-dependent in Ruby 1.8.6.

Parameters:

  • set1 (Set)
  • set2 (Set)

Returns:

  • (Boolean) —

    Whether or not the sets are hashcode equal



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# File 'lib/haml/util.rb', line 616

def set_eql?(set1, set2)
  return set1.eql?(set2) unless ruby1_8_6?
  set1.to_a.uniq.sort_by {|e| e.hash}.eql?(set2.to_a.uniq.sort_by {|e| e.hash})
end

#set_hash(set) ⇒ Fixnum

Returns the hash code for a set in a cross-version manner. Aggravatingly, this is order-dependent in Ruby 1.8.6.

Parameters:

  • set (Set)

Returns:

  • (Fixnum) —

    The order-independent hashcode of set



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# File 'lib/haml/util.rb', line 605

def set_hash(set)
  return set.hash unless ruby1_8_6?
  set.map {|e| e.hash}.uniq.sort.hash
end

#silence_haml_warnings { ... }

Silences all Haml warnings within a block.

Yields:

  • A block in which no Haml warnings will be printed



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# File 'lib/haml/util.rb', line 248

def silence_haml_warnings
  old_silence_warnings = @@silence_warnings
  @@silence_warnings = true
  yield
ensure
  @@silence_warnings = old_silence_warnings
end

#silence_warnings { ... }

Silence all output to STDERR within a block.

Yields:

  • A block in which no output will be printed to STDERR



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

def silence_warnings
  the_real_stderr, $stderr = $stderr, StringIO.new
  yield
ensure
  $stderr = the_real_stderr
end

#static_method_name(name, *vars) ⇒ String

Computes the name for a method defined via #def_static_method.

Parameters:

  • name (String) —

    The base name of the static method

  • vars (Array<Boolean>) —

    The static variable assignment

Returns:

  • (String) —

    The real name of the static method



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# File 'lib/haml/util.rb', line 690

def static_method_name(name, *vars)
  "#{name}_#{vars.map {|v| !!v}.join('_')}"
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/haml/util.rb', line 180

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

#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/haml/util.rb', line 162

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

#to_hash(arr) ⇒ Hash

Converts an array of [key, value] pairs to a hash. For example:

to_hash([[:foo, "bar"], [:baz, "bang"]])
  #=> {:foo => "bar", :baz => "bang"}

Parameters:

  • arr (Array<(Object, Object)>) —

    An array of pairs

Returns:

  • (Hash) —

    A hash



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# File 'lib/haml/util.rb', line 36

def to_hash(arr)
  arr.compact.inject({}) {|h, (k, v)| h[k] = v; h}
end

#windows? ⇒ Boolean

Whether or not this is running on Windows.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 376

def windows?
  RbConfig::CONFIG['host_os'] =~ /mswin|windows/i
end