Module: Sass::Script::Functions

Included in:
EvaluationContext
Defined in:
/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb

Overview

Methods in this module are accessible from the SassScript context. For example, you can write

$color: hsl(120deg, 100%, 50%)

and it will call #hsl.

The following functions are provided:

Note: These functions are described in more detail below.

RGB Functions

rgb($red, $green, $blue)
Creates a Color from red, green, and blue values.
rgba($red, $green, $blue, $alpha)
Creates a Color from red, green, blue, and alpha values.
red($color)
Gets the red component of a color.
green($color)
Gets the green component of a color.
blue($color)
Gets the blue component of a color.
mix($color1, $color2, [$weight])
Mixes two colors together.

HSL Functions

hsl($hue, $saturation, $lightness)
Creates a Color from hue, saturation, and lightness values.
hsla($hue, $saturation, $lightness, $alpha)
Creates a Color from hue, saturation, lightness, and alpha values.
hue($color)
Gets the hue component of a color.
saturation($color)
Gets the saturation component of a color.
lightness($color)
Gets the lightness component of a color.
adjust-hue($color, $degrees)
Changes the hue of a color.
lighten($color, $amount)
Makes a color lighter.
darken($color, $amount)
Makes a color darker.
saturate($color, $amount)
Makes a color more saturated.
desaturate($color, $amount)
Makes a color less saturated.
grayscale($color)
Converts a color to grayscale.
complement($color)
Returns the complement of a color.
invert($color)
Returns the inverse of a color.

Opacity Functions

alpha($color) / opacity($color)
Gets the alpha component (opacity) of a color.
rgba($color, $alpha)
Changes the alpha component for a color.
opacify($color, $amount) / fade-in($color, $amount)
Makes a color more opaque.
transparentize($color, $amount) / fade-out($color, $amount)
Makes a color more transparent.

Other Color Functions

adjust-color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])
Increases or decreases one or more components of a color.
scale-color($color, [$red], [$green], [$blue], [$saturation], [$lightness], [$alpha])
Fluidly scales one or more properties of a color.
change-color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])
Changes one or more properties of a color.
ie-hex-str($color)
Converts a color into the format understood by IE filters.

String Functions

unquote($string)
Removes quotes from a string.
quote($string)
Adds quotes to a string.
str-length($string)
Returns the number of characters in a string.
str-insert($string, $insert, $index)
Inserts $insert into $string at $index.
str-index($string, $substring)
Returns the index of the first occurance of $substring in $string.
str-slice($string, $start-at, [$end-at])
Extracts a substring from $string.
to-upper-case($string)
Converts a string to upper case.
to-lower-case($string)
Converts a string to lower case.

Number Functions

percentage($number)
Converts a unitless number to a percentage.
round($number)
Rounds a number to the nearest whole number.
ceil($number)
Rounds a number up to the next whole number.
floor($number)
Rounds a number down to the previous whole number.
abs($number)
Returns the absolute value of a number.
min($numbers…)
Finds the minimum of several numbers.
max($numbers…)
Finds the maximum of several numbers.
random([$limit])
Returns a random number.

List Functions

All list functions work for maps as well, treating them as lists of pairs.

length($list)
Returns the length of a list.
nth($list, $n)
Returns a specific item in a list.
join($list1, $list2, [$separator])
Joins together two lists into one.
append($list1, $val, [$separator])
Appends a single value onto the end of a list.
zip($lists…)
Combines several lists into a single multidimensional list.
index($list, $value)
Returns the position of a value within a list.
list-separator(#list)
Returns the separator of a list.

Map Functions

map-get($map, $key)
Returns the value in a map associated with a given key.
map-merge($map1, $map2)
Merges two maps together into a new map.
map-remove($map, $keys…)
Returns a new map with keys removed.
map-keys($map)
Returns a list of all keys in a map.
map-values($map)
Returns a list of all values in a map.
map-has-key($map, $key)
Returns whether a map has a value associated with a given key.
keywords($args)
Returns the keywords passed to a function that takes variable arguments.

Selector Functions

Selector functions are very liberal in the formats they support for selector arguments. They can take a plain string, a list of lists as returned by & or anything in between:

  • A plain sring, such as ".foo .bar, .baz .bang".
  • A space-separated list of strings such as (".foo" ".bar").
  • A comma-separated list of strings such as (".foo .bar", ".baz .bang").
  • A comma-separated list of space-separated lists of strings such as ((".foo" ".bar"), (".baz" ".bang")).

In general, selector functions allow placeholder selectors (%foo) but disallow parent-reference selectors (&).

selector-nest($selectors…)
Nests selector beneath one another like they would be nested in the stylesheet.
selector-append($selectors…)
Appends selectors to one another without spaces in between.
selector-extend($selector, $extendee, $extender)
Extends $extendee with $extender within $selector.
selector-replace($selector, $original, $replacement)
Replaces $original with $replacement within $selector.
selector-unify($selector1, $selector2)
Unifies two selectors to produce a selector that matches elements matched by both.
is-superselector($super, $sub)
Returns whether $super matches all the elements $sub does, and possibly more.
simple-selectors($selector)
Returns the simple selectors that comprise a compound selector.
selector-parse($selector)
Parses a selector into the format returned by &.

Introspection Functions

feature-exists($feature)
Returns whether a feature exists in the current Sass runtime.
variable-exists($name)
Returns whether a variable with the given name exists in the current scope.
global-variable-exists($name)
Returns whether a variable with the given name exists in the global scope.
function-exists($name)
Returns whether a function with the given name exists.
mixin-exists($name)
Returns whether a mixin with the given name exists.
inspect($value)
Returns the string representation of a value as it would be represented in Sass.
type-of($value)
Returns the type of a value.
unit($number)
Returns the unit(s) associated with a number.
unitless($number)
Returns whether a number has units.
comparable($number1, $number2)
Returns whether two numbers can be added, subtracted, or compared.
call($name, $args…)
Dynamically calls a Sass function.

Miscellaneous Functions

if($condition, $if-true, $if-false)
Returns one of two values, depending on whether or not $condition is true.
unique-id()
Returns a unique CSS identifier.

Adding Custom Functions

New Sass functions can be added by adding Ruby methods to this module. For example:

module Sass::Script::Functions
  def reverse(string)
    assert_type string, :String
    Sass::Script::Value::String.new(string.value.reverse)
  end
  declare :reverse, [:string]
end

Calling Functions.declare tells Sass the argument names for your function. If omitted, the function will still work, but will not be able to accept keyword arguments. Functions.declare can also allow your function to take arbitrary keyword arguments.

There are a few things to keep in mind when modifying this module. First of all, the arguments passed are Value objects. Value objects are also expected to be returned. This means that Ruby values must be unwrapped and wrapped.

Most Value objects support the value accessor for getting their Ruby values. Color objects, though, must be accessed using rgb, red, green, or blue.

Second, making Ruby functions accessible from Sass introduces the temptation to do things like database access within stylesheets. This is generally a bad idea; since Sass files are by default only compiled once, dynamic code is not a great fit.

If you really, really need to compile Sass on each request, first make sure you have adequate caching set up. Then you can use Engine to render the code, using the options parameter to pass in data that can be accessed from your Sass functions.

Within one of the functions in this module, methods of EvaluationContext can be used.

Caveats

When creating new Value objects within functions, be aware that it’s not safe to call #to_s (or other methods that use the string representation) on those objects without first setting the #options attribute.

Defined Under Namespace

Classes: EvaluationContext, Signature

Class Method Summary (collapse)

Instance Method Summary (collapse)

Class Method Details

+ declare(method_name, args, options = {})

Declare a Sass signature for a Ruby-defined function. This includes the names of the arguments, whether the function takes a variable number of arguments, and whether the function takes an arbitrary set of keyword arguments.

It’s not necessary to declare a signature for a function. However, without a signature it won’t support keyword arguments.

A single function can have multiple signatures declared as long as each one takes a different number of arguments. It’s also possible to declare multiple signatures that all take the same number of arguments, but none of them but the first will be used unless the user uses keyword arguments.

Examples:

declare :rgba, [:hex, :alpha]
declare :rgba, [:red, :green, :blue, :alpha]
declare :accepts_anything, [], :var_args => true, :var_kwargs => true
declare :some_func, [:foo, :bar, :baz], :var_kwargs => true

Parameters:

  • method_name (Symbol)

    The name of the method whose signature is being declared.

  • args (Array<Symbol>)

    The names of the arguments for the function signature.

  • options (Hash) (defaults to: {})

    a customizable set of options

Options Hash (options):

  • :var_args (Boolean) — default: false

    Whether the function accepts a variable number of (unnamed) arguments in addition to the named arguments.

  • :var_kwargs (Boolean) — default: false

    Whether the function accepts other keyword arguments in addition to those in :args. If this is true, the Ruby function will be passed a hash from strings to Values as the last argument. In addition, if this is true and :var_args is not, Sass will ensure that the last argument passed is a hash.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 396

def self.declare(method_name, args, options = {})
  delayed_args = []
  args = args.map do |a|
    a = a.to_s
    if a[0] == ?&
      a = a[1..-1]
      delayed_args << a
    end
    a
  end
  # We don't expose this functionality except to certain builtin methods.
  if delayed_args.any? && method_name != :if
    raise ArgumentError.new("Delayed arguments are not allowed for method #{method_name}")
  end
  @signatures[method_name] ||= []
  @signatures[method_name] << Signature.new(
    args,
    delayed_args,
    options[:var_args],
    options[:var_kwargs],
    options[:deprecated] && options[:deprecated].map {|a| a.to_s})
end

+ (Random) random_number_generator

Get Sass’s internal random number generator.

Returns:

  • (Random)


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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 470

def self.random_number_generator
  @random_number_generator ||= Sass::Util::CrossPlatformRandom.new
end

+ (Integer) random_seed=(seed)

Sets the random seed used by Sass’s internal random number generator.

This can be used to ensure consistent random number sequences which allows for consistent results when testing, etc.

Parameters:

  • seed (Integer)

Returns:

  • (Integer)

    The same seed.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 463

def self.random_seed=(seed)
  @random_number_generator = Sass::Util::CrossPlatformRandom.new(seed)
end

+ ({Symbol => Object}?) signature(method_name, arg_arity, kwarg_arity)

Determine the correct signature for the number of arguments passed in for a given function. If no signatures match, the first signature is returned for error messaging.

Parameters:

  • method_name (Symbol)

    The name of the Ruby function to be called.

  • arg_arity (Fixnum)

    The number of unnamed arguments the function was passed.

  • kwarg_arity (Fixnum)

    The number of keyword arguments the function was passed.

Returns:

  • ({Symbol => Object}, nil)

    The signature options for the matching signature, or nil if no signatures are declared for this function. See declare.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 430

def self.signature(method_name, arg_arity, kwarg_arity)
  return unless @signatures[method_name]
  @signatures[method_name].each do |signature|
    sig_arity = signature.args.size
    return signature if sig_arity == arg_arity + kwarg_arity
    next unless sig_arity < arg_arity + kwarg_arity

    # We have enough args.
    # Now we need to figure out which args are varargs
    # and if the signature allows them.
    t_arg_arity, t_kwarg_arity = arg_arity, kwarg_arity
    if sig_arity > t_arg_arity
      # we transfer some kwargs arity to args arity
      # if it does not have enough args -- assuming the names will work out.
      t_kwarg_arity -= (sig_arity - t_arg_arity)
      t_arg_arity = sig_arity
    end

    if   (t_arg_arity == sig_arity ||   t_arg_arity > sig_arity && signature.var_args) &&
       (t_kwarg_arity == 0         || t_kwarg_arity > 0         && signature.var_kwargs)
      return signature
    end
  end
  @signatures[method_name].first
end

Instance Method Details

- (Sass::Script::Value::Number) abs($number)

Returns the absolute value of a number.

Examples:

abs(10px) => 10px
abs(-10px) => 10px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1741

def abs(number)
  numeric_transformation(number) {|n| n.abs}
end

- (Sass::Script::Value::Color) adjust_color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])

Increases or decreases one or more properties of a color. This can change the red, green, blue, hue, saturation, value, and alpha properties. The properties are specified as keyword arguments, and are added to or subtracted from the color’s current value for that property.

All properties are optional. You can’t specify both RGB properties ($red, $green, $blue) and HSL properties ($hue, $saturation, $value) at the same time.

Examples:

adjust-color(#102030, $blue: 5) => #102035
adjust-color(#102030, $red: -5, $blue: 5) => #0b2035
adjust-color(hsl(25, 100%, 80%), $lightness: -30%, $alpha: -0.4) => hsla(25, 100%, 50%, 0.6)

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type or out-of bounds, or if RGB properties and HSL properties are adjusted at the same time



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1098

def adjust_color(color, kwargs)
  assert_type color, :Color, :color
  with = Sass::Util.map_hash(
      "red" => [-255..255, ""],
      "green" => [-255..255, ""],
      "blue" => [-255..255, ""],
      "hue" => nil,
      "saturation" => [-100..100, "%"],
      "lightness" => [-100..100, "%"],
      "alpha" => [-1..1, ""]
    ) do |name, (range, units)|

    val = kwargs.delete(name)
    next unless val
    assert_type val, :Number, name
    Sass::Util.check_range("$#{name}: Amount", range, val, units) if range
    adjusted = color.send(name) + val.value
    adjusted = [0, Sass::Util.restrict(adjusted, range)].max if range
    [name.to_sym, adjusted]
  end

  unless kwargs.empty?
    name, val = kwargs.to_a.first
    raise ArgumentError.new("Unknown argument $#{name} (#{val})")
  end

  color.with(with)
end

- (Sass::Script::Value::Color) adjust_hue($color, $degrees)

Changes the hue of a color. Takes a color and a number of degrees (usually between -360deg and 360deg), and returns a color with the hue rotated along the color wheel by that amount.

Examples:

adjust-hue(hsl(120, 30%, 90%), 60deg) => hsl(180, 30%, 90%)
adjust-hue(hsl(120, 30%, 90%), -60deg) => hsl(60, 30%, 90%)
adjust-hue(#811, 45deg) => #886a11

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if either parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1036

def adjust_hue(color, degrees)
  assert_type color, :Color, :color
  assert_type degrees, :Number, :degrees
  color.with(:hue => color.hue + degrees.value)
end

- (Sass::Script::Value::Number) alpha($color)

Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified.

This function also supports the proprietary Microsoft alpha(opacity=20) syntax as a special case.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 866

def alpha(*args)
  if args.all? do |a|
       a.is_a?(Sass::Script::Value::String) && a.type == :identifier &&
         a.value =~ /^[a-zA-Z]+\s*=/
     end
    # Support the proprietary MS alpha() function
    return identifier("alpha(#{args.map {|a| a.to_s}.join(", ")})")
  end

  raise ArgumentError.new("wrong number of arguments (#{args.size} for 1)") if args.size != 1

  assert_type args.first, :Color, :color
  number(args.first.alpha)
end

- (Sass::Script::Value::List) append($list, $val, $separator:auto)

Appends a single value onto the end of a list.

Unless the $separator argument is passed, if the list had only one item, the resulting list will be space-separated.

Examples:

append(10px 20px, 30px) => 10px 20px 30px
append((blue, red), green) => blue, red, green
append(10px 20px, 30px 40px) => 10px 20px (30px 40px)
append(10px, 20px, comma) => 10px, 20px
append((blue, red), green, space) => blue red green

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1909

def append(list, val, separator = identifier("auto"))
  assert_type separator, :String, :separator
  unless %w[auto space comma].include?(separator.value)
    raise ArgumentError.new("Separator name must be space, comma, or auto")
  end
  sep = if separator.value == 'auto'
          list.separator || :space
        else
          separator.value.to_sym
        end
  list(list.to_a + [val], sep)
end

- (Sass::Script::Value::Number) blue($color)

Gets the blue component of a color. Calculated from HSL where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 796

def blue(color)
  assert_type color, :Color, :color
  number(color.blue)
end

- call($name, $args...)

Dynamically calls a function. This can call user-defined functions, built-in functions, or plain CSS functions. It will pass along all arguments, including keyword arguments, to the called function.

Examples:

call(rgb, 10, 100, 255) => #0a64ff
call(scale-color, #0a64ff, $lightness: -10%) => #0058ef

$fn: nth;
call($fn, (a b c), 2) => b

Parameters:

  • $name (String)

    The name of the function to call.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2171

def call(name, *args)
  assert_type name, :String, :name
  kwargs = args.last.is_a?(Hash) ? args.pop : {}
  funcall = Sass::Script::Tree::Funcall.new(
    name.value,
    args.map {|a| Sass::Script::Tree::Literal.new(a)},
    Sass::Util.map_vals(kwargs) {|v| Sass::Script::Tree::Literal.new(v)},
    nil,
    nil)
  funcall.options = options
  perform(funcall)
end

- (Sass::Script::Value::Number) ceil($number)

Rounds a number up to the next whole number.

Examples:

ceil(10.4px) => 11px
ceil(10.6px) => 11px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1713

def ceil(number)
  numeric_transformation(number) {|n| n.ceil}
end

- (Sass::Script::Value::Color) change_color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])

Changes one or more properties of a color. This can change the red, green, blue, hue, saturation, value, and alpha properties. The properties are specified as keyword arguments, and replace the color’s current value for that property.

All properties are optional. You can’t specify both RGB properties ($red, $green, $blue) and HSL properties ($hue, $saturation, $value) at the same time.

Examples:

change-color(#102030, $blue: 5) => #102005
change-color(#102030, $red: 120, $blue: 5) => #782005
change-color(hsl(25, 100%, 80%), $lightness: 40%, $alpha: 0.8) => hsla(25, 100%, 40%, 0.8)

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type or out-of bounds, or if RGB properties and HSL properties are adjusted at the same time



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1240

def change_color(color, kwargs)
  assert_type color, :Color, :color
  with = Sass::Util.map_hash(
    'red' => ['Red value', 0..255],
    'green' => ['Green value', 0..255],
    'blue' => ['Blue value', 0..255],
    'hue' => [],
    'saturation' => ['Saturation', 0..100, '%'],
    'lightness' => ['Lightness', 0..100, '%'],
    'alpha' => ['Alpha channel', 0..1]
  ) do |name, (desc, range, unit)|
    val = kwargs.delete(name)
    next unless val
    assert_type val, :Number, name

    if range
      val = Sass::Util.check_range(desc, range, val, unit)
    else
      val = val.value
    end

    [name.to_sym, val]
  end

  unless kwargs.empty?
    name, val = kwargs.to_a.first
    raise ArgumentError.new("Unknown argument $#{name} (#{val})")
  end

  color.with(with)
end

- (Sass::Script::Value::Bool) comparable($number1, $number2)

Returns whether two numbers can added, subtracted, or compared.

Examples:

comparable(2px, 1px) => true
comparable(100px, 3em) => false
comparable(10cm, 3mm) => true

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if either parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1666

def comparable(number1, number2)
  assert_type number1, :Number, :number1
  assert_type number2, :Number, :number2
  bool(number1.comparable_to?(number2))
end

- (Sass::Script::Value::Color) complement($color)

Returns the complement of a color. This is identical to adjust-hue(color, 180deg).

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1359

def complement(color)
  adjust_hue color, number(180)
end

- (Sass::Script::Value::String) counter($args...)

This function only exists as a workaround for IE7‘s content: counter bug. It works identically to any other plain-CSS function, except it avoids adding spaces between the argument commas.

Examples:

counter(item, ".") => counter(item,".")

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2194

def counter(*args)
  identifier("counter(#{args.map {|a| a.to_s(options)}.join(',')})")
end

- (Sass::Script::Value::String) counters($args...)

This function only exists as a workaround for IE7‘s content: counter bug. It works identically to any other plain-CSS function, except it avoids adding spaces between the argument commas.

Examples:

counters(item, ".") => counters(item,".")

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2208

def counters(*args)
  identifier("counters(#{args.map {|a| a.to_s(options)}.join(',')})")
end

- (Sass::Script::Value::Color) darken($color, $amount)

Makes a color darker. Takes a color and a number between 0% and 100%, and returns a color with the lightness decreased by that amount.

Examples:

darken(hsl(25, 100%, 80%), 30%) => hsl(25, 100%, 50%)
darken(#800, 20%) => #200

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 975

def darken(color, amount)
  _adjust(color, amount, :lightness, 0..100, :-, "%")
end

- (Sass::Script::Value::Color) desaturate($color, $amount)

Makes a color less saturated. Takes a color and a number between 0% and 100%, and returns a color with the saturation decreased by that value.

Examples:

desaturate(hsl(120, 30%, 90%), 20%) => hsl(120, 10%, 90%)
desaturate(#855, 20%) => #726b6b

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1017

def desaturate(color, amount)
  _adjust(color, amount, :saturation, 0..100, :-, "%")
end

- (Sass::Script::Value::Bool) feature_exists($feature)

Returns whether a feature exists in the current Sass runtime.

The following features are supported:

  • global-variable-shadowing indicates that a local variable will shadow a global variable unless !global is used.

  • extend-selector-pseudoclass indicates that @extend will reach into selector pseudoclasses like :not.

  • units-level-3 indicates full support for unit arithmetic using units defined in the Values and Units Level 3 spec.

  • at-error indicates that the Sass @error directive is supported.

Examples:

feature-exists(some-feature-that-exists) => true
feature-exists(what-is-this-i-dont-know) => false

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $feature isn’t a string



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1614

def feature_exists(feature)
  assert_type feature, :String, :feature
  bool(Sass.has_feature?(feature.value))
end

- (Sass::Script::Value::Number) floor($number)

Rounds a number down to the previous whole number.

Examples:

floor(10.4px) => 10px
floor(10.6px) => 10px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1727

def floor(number)
  numeric_transformation(number) {|n| n.floor}
end

- (Sass::Script::Value::Bool) function_exists($name)

Check whether a function with the given name exists.

Examples:

function-exists(lighten) => true

@function myfunc { @return "something"; }
function-exists(myfunc) => true

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2268

def function_exists(name)
  assert_type name, :String, :name
  exists = Sass::Script::Functions.callable?(name.value.tr("-", "_"))
  exists ||= environment.function(name.value)
  bool(exists)
end

- (Sass::Script::Value::Bool) global_variable_exists($name)

Check whether a variable with the given name exists in the global scope (at the top level of the file).

Examples:

$a-false-value: false;
global-variable-exists(a-false-value) => true

.foo {
  $some-var: false;
  @if global-variable-exists(some-var) { /* false, doesn't run */ }
}

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2250

def global_variable_exists(name)
  assert_type name, :String, :name
  bool(environment.global_env.var(name.value))
end

- (Sass::Script::Value::Color) grayscale($color)

Converts a color to grayscale. This is identical to desaturate(color, 100%).

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1343

def grayscale(color)
  if color.is_a?(Sass::Script::Value::Number)
    return identifier("grayscale(#{color})")
  end
  desaturate color, number(100)
end

- (Sass::Script::Value::Number) green($color)

Gets the green component of a color. Calculated from HSL where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 780

def green(color)
  assert_type color, :Color, :color
  number(color.green)
end

- (Sass::Script::Value::Color) hsl($hue, $saturation, $lightness)

Creates a Color from hue, saturation, and lightness values. Uses the algorithm from the CSS3 spec.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $saturation or $lightness are out of bounds or any parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 712

def hsl(hue, saturation, lightness)
  hsla(hue, saturation, lightness, number(1))
end

- (Sass::Script::Value::Color) hsla($hue, $saturation, $lightness, $alpha)

Creates a Color from hue, saturation, lightness, and alpha values. Uses the algorithm from the CSS3 spec.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $saturation, $lightness, or $alpha are out of bounds or any parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 736

def hsla(hue, saturation, lightness, alpha)
  assert_type hue, :Number, :hue
  assert_type saturation, :Number, :saturation
  assert_type lightness, :Number, :lightness
  assert_type alpha, :Number, :alpha

  h = hue.value
  s = saturation.value
  l = lightness.value

  # Don't store the string representation for function-created colors, both
  # because it's not very useful and because some functions aren't supported
  # on older browsers.
  Sass::Script::Value::Color.new(
    :hue => h, :saturation => s, :lightness => l, :alpha => alpha.value)
end

- (Sass::Script::Value::Number) hue($color)

Returns the hue component of a color. See the CSS3 HSL specification. Calculated from RGB where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 814

def hue(color)
  assert_type color, :Color, :color
  number(color.hue, "deg")
end

- (Sass::Script::Value::String) ie_hex_str($color)

Converts a color into the format understood by IE filters.

Examples:

ie-hex-str(#abc) => #FFAABBCC
ie-hex-str(#3322BB) => #FF3322BB
ie-hex-str(rgba(0, 255, 0, 0.5)) => #8000FF00

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1054

def ie_hex_str(color)
  assert_type color, :Color, :color
  alpha = (color.alpha * 255).round.to_s(16).rjust(2, '0')
  identifier("##{alpha}#{color.send(:hex_str)[1..-1]}".upcase)
end

- (Sass::Script::Value::Base) if($condition, $if-true, $if-false)

Returns one of two values, depending on whether or not $condition is true. Just like in @if, all values other than false and null are considered to be true.

Examples:

if(true, 1px, 2px) => 1px
if(false, 1px, 2px) => 2px

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2132

def if(condition, if_true, if_false)
  if condition.to_bool
    perform(if_true)
  else
    perform(if_false)
  end
end

- (Sass::Script::Value::Number, Sass::Script::Value::Null) index($list, $value)

Returns the position of a value within a list. If the value isn’t found, returns null instead.

Note that unlike some languages, the first item in a Sass list is number 1, the second number 2, and so forth.

This can return the position of a pair in a map as well.

Examples:

index(1px solid red, solid) => 2
index(1px solid red, dashed) => null
index((width: 10px, height: 20px), (height 20px)) => 2

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1970

def index(list, value)
  index = list.to_a.index {|e| e.eq(value).to_bool}
  index ? number(index + 1) : null
end

- (Sass::Script::Value::String) inspect($value)

Return a string containing the value as its Sass representation.

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2300

def inspect(value)
  unquoted_string(value.to_sass)
end

- (Sass::Script::Value::Color) invert($color)

Returns the inverse (negative) of a color. The red, green, and blue values are inverted, while the opacity is left alone.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1371

def invert(color)
  if color.is_a?(Sass::Script::Value::Number)
    return identifier("invert(#{color})")
  end

  assert_type color, :Color, :color
  color.with(
    :red => (255 - color.red),
    :green => (255 - color.green),
    :blue => (255 - color.blue))
end

- (Sass::Script::Value::Bool) is_superselector($super, $sub)

Returns whether $super is a superselector of $sub. This means that $super matches all the elements that $sub matches, as well as possibly additional elements. In general, simpler selectors tend to be superselectors of more complex oned.

Examples:

is-superselector(".foo", ".foo.bar") => true
is-superselector(".foo.bar", ".foo") => false
is-superselector(".bar", ".foo .bar") => true
is-superselector(".foo .bar", ".bar") => false

Returns Whether $selector1 is a superselector of $selector2.

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2597

def is_superselector(sup, sub)
  sup = parse_selector(sup, :super)
  sub = parse_selector(sub, :sub)
  bool(sup.superselector?(sub))
end

- (Sass::Script::Value::List) join($list1, $list2, $separator:auto)

Joins together two lists into one.

Unless $separator is passed, if one list is comma-separated and one is space-separated, the first parameter’s separator is used for the resulting list. If both lists have fewer than two items, spaces are used for the resulting list.

Examples:

join(10px 20px, 30px 40px) => 10px 20px 30px 40px
join((blue, red), (#abc, #def)) => blue, red, #abc, #def
join(10px, 20px) => 10px 20px
join(10px, 20px, comma) => 10px, 20px
join((blue, red), (#abc, #def), space) => blue red #abc #def

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1876

def join(list1, list2, separator = identifier("auto"))
  assert_type separator, :String, :separator
  unless %w[auto space comma].include?(separator.value)
    raise ArgumentError.new("Separator name must be space, comma, or auto")
  end
  sep = if separator.value == 'auto'
          list1.separator || list2.separator || :space
        else
          separator.value.to_sym
        end
  list(list1.to_a + list2.to_a, sep)
end

- (Sass::Script::Value::Map) keywords($args)

Returns the map of named arguments passed to a function or mixin that takes a variable argument list. The argument names are strings, and they do not contain the leading $.

Examples:

@mixin foo($args...) {
  @debug keywords($args); //=> (arg1: val, arg2: val)
}

@include foo($arg1: val, $arg2: val);

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $args isn’t a variable argument list



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2113

def keywords(args)
  assert_type args, :ArgList, :args
  map(Sass::Util.map_keys(args.keywords.as_stored) {|k| Sass::Script::Value::String.new(k)})
end

- (Sass::Script::Value::Number) length($list)

Return the length of a list.

This can return the number of pairs in a map as well.

Examples:

length(10px) => 1
length(10px 20px 30px) => 3
length((width: 10px, height: 20px)) => 2

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1791

def length(list)
  number(list.to_a.size)
end

- (Sass::Script::Value::Color) lighten($color, $amount)

Makes a color lighter. Takes a color and a number between 0% and 100%, and returns a color with the lightness increased by that amount.

Examples:

lighten(hsl(0, 0%, 0%), 30%) => hsl(0, 0, 30)
lighten(#800, 20%) => #e00

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 956

def lighten(color, amount)
  _adjust(color, amount, :lightness, 0..100, :+, "%")
end

- (Sass::Script::Value::Number) lightness($color)

Returns the lightness component of a color. See the CSS3 HSL specification. Calculated from RGB where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 850

def lightness(color)
  assert_type color, :Color, :color
  number(color.lightness, "%")
end

- (Sass::Script::Value::String) list_separator($list)

Returns the separator of a list. If the list doesn’t have a separator due to having fewer than two elements, returns space.

Examples:

list-separator(1px 2px 3px) => space
list-separator(1px, 2px, 3px) => comma
list-separator('foo') => space

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1986

def list_separator(list)
  identifier((list.separator || :space).to_s)
end

- (Sass::Script::Value::Base) map_get($map, $key)

Returns the value in a map associated with the given key. If the map doesn’t have such a key, returns null.

Examples:

map-get(("foo": 1, "bar": 2), "foo") => 1
map-get(("foo": 1, "bar": 2), "bar") => 2
map-get(("foo": 1, "bar": 2), "baz") => null

Returns:

Raises:

  • (ArgumentError)

    if $map is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2004

def map_get(map, key)
  assert_type map, :Map, :map
  map.to_h[key] || null
end

- (Sass::Script::Value::Bool) map_has_key($map, $key)

Returns whether a map has a value associated with a given key.

Examples:

map-has-key(("foo": 1, "bar": 2), "foo") => true
map-has-key(("foo": 1, "bar": 2), "baz") => false

Returns:

Raises:

  • (ArgumentError)

    if $map is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2093

def map_has_key(map, key)
  assert_type map, :Map, :map
  bool(map.to_h.has_key?(key))
end

- (List) map_keys($map)

Returns a list of all keys in a map.

Examples:

map-keys(("foo": 1, "bar": 2)) => "foo", "bar"

Parameters:

  • $map (Map)

Returns:

  • (List)

    the list of keys, comma-separated

Raises:

  • (ArgumentError)

    if $map is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2061

def map_keys(map)
  assert_type map, :Map, :map
  list(map.to_h.keys, :comma)
end

- (Sass::Script::Value::Map) map_merge($map1, $map2)

Merges two maps together into a new map. Keys in $map2 will take precedence over keys in $map1.

This is the best way to add new values to a map.

All keys in the returned map that also appear in $map1 will have the same order as in $map1. New keys from $map2 will be placed at the end of the map.

Examples:

map-merge(("foo": 1), ("bar": 2)) => ("foo": 1, "bar": 2)
map-merge(("foo": 1, "bar": 2), ("bar": 3)) => ("foo": 1, "bar": 3)

Returns:

Raises:

  • (ArgumentError)

    if either parameter is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2027

def map_merge(map1, map2)
  assert_type map1, :Map, :map1
  assert_type map2, :Map, :map2
  map(map1.to_h.merge(map2.to_h))
end

- (Sass::Script::Value::Map) map_remove($map, $keys...)

Returns a new map with keys removed.

Examples:

map-remove(("foo": 1, "bar": 2), "bar") => ("foo": 1)
map-remove(("foo": 1, "bar": 2, "baz": 3), "bar", "baz") => ("foo": 1)
map-remove(("foo": 1, "bar": 2), "baz") => ("foo": 1, "bar": 2)

Returns:

Raises:

  • (ArgumentError)

    if $map is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2045

def map_remove(map, *keys)
  assert_type map, :Map, :map
  hash = map.to_h.dup
  hash.delete_if {|key, _| keys.include?(key)}
  map(hash)
end

- (List) map_values($map)

Returns a list of all values in a map. This list may include duplicate values, if multiple keys have the same value.

Examples:

map-values(("foo": 1, "bar": 2)) => 1, 2
map-values(("foo": 1, "bar": 2, "baz": 1)) => 1, 2, 1

Parameters:

  • $map (Map)

Returns:

  • (List)

    the list of values, comma-separated

Raises:

  • (ArgumentError)

    if $map is not a map



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2077

def map_values(map)
  assert_type map, :Map, :map
  list(map.to_h.values, :comma)
end

- (Sass::Script::Value::Number) max($numbers...)

Finds the maximum of several numbers. This function takes any number of arguments.

Examples:

max(1px, 4px) => 4px
max(5em, 3em, 4em) => 5em

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any argument isn’t a number, or if not all of the arguments have comparable units



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1774

def max(*values)
  values.each {|v| assert_type v, :Number}
  values.inject {|max, val| max.gt(val).to_bool ? max : val}
end

- (Sass::Script::Value::Number) min($numbers...)

Finds the minimum of several numbers. This function takes any number of arguments.

Examples:

min(1px, 4px) => 1px
min(5em, 3em, 4em) => 3em

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any argument isn’t a number, or if not all of the arguments have comparable units



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1757

def min(*numbers)
  numbers.each {|n| assert_type n, :Number}
  numbers.inject {|min, num| min.lt(num).to_bool ? min : num}
end

- (Sass::Script::Value::Color) mix($color1, $color2, $weight:50%)

Mixes two colors together. Specifically, takes the average of each of the RGB components, optionally weighted by the given percentage. The opacity of the colors is also considered when weighting the components.

The weight specifies the amount of the first color that should be included in the returned color. The default, 50%, means that half the first color and half the second color should be used. 25% means that a quarter of the first color and three quarters of the second color should be used.

Examples:

mix(#f00, #00f) => #7f007f
mix(#f00, #00f, 25%) => #3f00bf
mix(rgba(255, 0, 0, 0.5), #00f) => rgba(63, 0, 191, 0.75)

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $weight is out of bounds or any parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1295

def mix(color1, color2, weight = number(50))
  assert_type color1, :Color, :color1
  assert_type color2, :Color, :color2
  assert_type weight, :Number, :weight

  Sass::Util.check_range("Weight", 0..100, weight, '%')

  # This algorithm factors in both the user-provided weight (w) and the
  # difference between the alpha values of the two colors (a) to decide how
  # to perform the weighted average of the two RGB values.
  #
  # It works by first normalizing both parameters to be within [-1, 1],
  # where 1 indicates "only use color1", -1 indicates "only use color2", and
  # all values in between indicated a proportionately weighted average.
  #
  # Once we have the normalized variables w and a, we apply the formula
  # (w + a)/(1 + w*a) to get the combined weight (in [-1, 1]) of color1.
  # This formula has two especially nice properties:
  #
  #   * When either w or a are -1 or 1, the combined weight is also that number
  #     (cases where w * a == -1 are undefined, and handled as a special case).
  #
  #   * When a is 0, the combined weight is w, and vice versa.
  #
  # Finally, the weight of color1 is renormalized to be within [0, 1]
  # and the weight of color2 is given by 1 minus the weight of color1.
  p = (weight.value / 100.0).to_f
  w = p * 2 - 1
  a = color1.alpha - color2.alpha

  w1 = ((w * a == -1 ? w : (w + a) / (1 + w * a)) + 1) / 2.0
  w2 = 1 - w1

  rgba = color1.rgb.zip(color2.rgb).map {|v1, v2| v1 * w1 + v2 * w2}
  rgba << color1.alpha * p + color2.alpha * (1 - p)
  rgb_color(*rgba)
end

- (Sass::Script::Value::Bool) mixin_exists($name)

Check whether a mixin with the given name exists.

Examples:

mixin-exists(nonexistent) => false

@mixin red-text { color: red; }
mixin-exists(red-text) => true

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2288

def mixin_exists(name)
  assert_type name, :String, :name
  bool(environment.mixin(name.value))
end

- (Sass::Script::Value::Base) nth($list, $n)

Gets the nth item in a list.

Note that unlike some languages, the first item in a Sass list is number 1, the second number 2, and so forth.

This can return the nth pair in a map as well.

Negative index values address elements in reverse order, starting with the last element in the list.

Examples:

nth(10px 20px 30px, 1) => 10px
nth((Helvetica, Arial, sans-serif), 3) => sans-serif
nth((width: 10px, length: 20px), 2) => length, 20px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $n isn’t an integer between 1 and the length of $list



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1847

def nth(list, n)
  assert_type n, :Number, :n
  Sass::Script::Value::List.assert_valid_index(list, n)

  index = n.to_i > 0 ? n.to_i - 1 : n.to_i
  list.to_a[index]
end

- (Sass::Script::Value::Color) opacify($color, $amount) Also known as: fade_in

Makes a color more opaque. Takes a color and a number between 0 and 1, and returns a color with the opacity increased by that amount.

Examples:

opacify(rgba(0, 0, 0, 0.5), 0.1) => rgba(0, 0, 0, 0.6)
opacify(rgba(0, 0, 17, 0.8), 0.2) => #001

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 912

def opacify(color, amount)
  _adjust(color, amount, :alpha, 0..1, :+)
end

- (Sass::Script::Value::Number) opacity($color)

Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 889

def opacity(color)
  if color.is_a?(Sass::Script::Value::Number)
    return identifier("opacity(#{color})")
  end
  assert_type color, :Color, :color
  number(color.alpha)
end

- (Sass::Script::Value::Number) percentage($number)

Converts a unitless number to a percentage.

Examples:

percentage(0.2) => 20%
percentage(100px / 50px) => 200%

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a unitless number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1682

def percentage(number)
  unless number.is_a?(Sass::Script::Value::Number) && number.unitless?
    raise ArgumentError.new("$number: #{number.inspect} is not a unitless number")
  end
  number(number.value * 100, '%')
end

- (Sass::Script::Value::String) quote($string)

Add quotes to a string if the string isn’t quoted, or returns the same string if it is.

Examples:

quote("foo") => "foo"
quote(foo) => "foo"

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $string isn’t a string

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1415

def quote(string)
  assert_type string, :String, :string
  if string.type != :string
    quoted_string(string.value)
  else
    string
  end
end

- (Sass::Script::Value::Number) random - (Sass::Script::Value::Number) random($limit)

Overloads:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2314

def random(limit = nil)
  generator = Sass::Script::Functions.random_number_generator
  if limit
    assert_integer limit, "limit"
    if limit.value < 1
      raise ArgumentError.new("$limit #{limit} must be greater than or equal to 1")
    end
    number(1 + generator.rand(limit.value))
  else
    number(generator.rand)
  end
end

- (Sass::Script::Value::Number) red($color)

Gets the red component of a color. Calculated from HSL where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 764

def red(color)
  assert_type color, :Color, :color
  number(color.red)
end

- (Sass::Script::Value::Color) rgb($red, $green, $blue)

Creates a Color object from red, green, and blue values.

Parameters:

  • $red (Sass::Script::Value::Number)

    The amount of red in the color. Must be between 0 and 255 inclusive, or between 0% and 100% inclusive

  • $green (Sass::Script::Value::Number)

    The amount of green in the color. Must be between 0 and 255 inclusive, or between 0% and 100% inclusive

  • $blue (Sass::Script::Value::Number)

    The amount of blue in the color. Must be between 0 and 255 inclusive, or between 0% and 100% inclusive

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type or out of bounds

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 624

def rgb(red, green, blue)
  assert_type red, :Number, :red
  assert_type green, :Number, :green
  assert_type blue, :Number, :blue

  color_attrs = [[red, :red], [green, :green], [blue, :blue]].map do |(c, name)|
    if c.is_unit?("%")
      c.value * 255 / 100.0
    elsif c.unitless?
      c.value
    else
      raise ArgumentError.new("Expected #{c} to be unitless or have a unit of % but got #{c}")
    end
  end

  # Don't store the string representation for function-created colors, both
  # because it's not very useful and because some functions aren't supported
  # on older browsers.
  Sass::Script::Value::Color.new(color_attrs)
end

- (Sass::Script::Value::Color) rgba($red, $green, $blue, $alpha) - (Sass::Script::Value::Color) rgba($color, $alpha)

Creates a Color from red, green, blue, and alpha values.

Overloads:

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 677

def rgba(*args)
  case args.size
  when 2
    color, alpha = args

    assert_type color, :Color, :color
    assert_type alpha, :Number, :alpha

    color.with(:alpha => alpha.value)
  when 4
    red, green, blue, alpha = args
    rgba(rgb(red, green, blue), alpha)
  else
    raise ArgumentError.new("wrong number of arguments (#{args.size} for 4)")
  end
end

- (Sass::Script::Value::Number) round($number)

Rounds a number to the nearest whole number.

Examples:

round(10.4px) => 10px
round(10.6px) => 11px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1699

def round(number)
  numeric_transformation(number) {|n| n.round}
end

- (Sass::Script::Value::Color) saturate($color, $amount)

Makes a color more saturated. Takes a color and a number between 0% and 100%, and returns a color with the saturation increased by that amount.

Examples:

saturate(hsl(120, 30%, 90%), 20%) => hsl(120, 50%, 90%)
saturate(#855, 20%) => #9e3f3f

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 994

def saturate(color, amount = nil)
  # Support the filter effects definition of saturate.
  # https://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/index.html
  return identifier("saturate(#{color})") if amount.nil?
  _adjust(color, amount, :saturation, 0..100, :+, "%")
end

- (Sass::Script::Value::Number) saturation($color)

Returns the saturation component of a color. See the CSS3 HSL specification. Calculated from RGB where necessary via this algorithm.

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $color isn’t a color



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 832

def saturation(color)
  assert_type color, :Color, :color
  number(color.saturation, "%")
end

- (Sass::Script::Value::Color) scale_color($color, [$red], [$green], [$blue], [$saturation], [$lightness], [$alpha])

Fluidly scales one or more properties of a color. Unlike adjust-color, which changes a color’s properties by fixed amounts, scale-color fluidly changes them based on how high or low they already are. That means that lightening an already-light color with scale-color won’t change the lightness much, but lightening a dark color by the same amount will change it more dramatically. This has the benefit of making scale-color($color, ...) have a similar effect regardless of what $color is.

For example, the lightness of a color can be anywhere between 0% and 100%. If scale-color($color, $lightness: 40%) is called, the resulting color’s lightness will be 40% of the way between its original lightness and 100. If scale-color($color, $lightness: -40%) is called instead, the lightness will be 40% of the way between the original and 0.

This can change the red, green, blue, saturation, value, and alpha properties. The properties are specified as keyword arguments. All arguments should be percentages between 0% and 100%.

All properties are optional. You can’t specify both RGB properties ($red, $green, $blue) and HSL properties ($saturation, $value) at the same time.

Examples:

scale-color(hsl(120, 70%, 80%), $lightness: 50%) => hsl(120, 70%, 90%)
scale-color(rgb(200, 150%, 170%), $green: -40%, $blue: 70%) => rgb(200, 90, 229)
scale-color(hsl(200, 70%, 80%), $saturation: -90%, $alpha: -30%) => hsla(200, 7%, 80%, 0.7)

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type or out-of bounds, or if RGB properties and HSL properties are adjusted at the same time



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1171

def scale_color(color, kwargs)
  assert_type color, :Color, :color
  with = Sass::Util.map_hash(
      "red" => 255,
      "green" => 255,
      "blue" => 255,
      "saturation" => 100,
      "lightness" => 100,
      "alpha" => 1
    ) do |name, max|

    val = kwargs.delete(name)
    next unless val
    assert_type val, :Number, name
    assert_unit val, '%', name
    Sass::Util.check_range("$#{name}: Amount", -100..100, val, '%')

    current = color.send(name)
    scale = val.value / 100.0
    diff = scale > 0 ? max - current : current
    [name.to_sym, current + diff * scale]
  end

  unless kwargs.empty?
    name, val = kwargs.to_a.first
    raise ArgumentError.new("Unknown argument $#{name} (#{val})")
  end

  color.with(with)
end

- (Sass::Script::Value::List) selector_append($selectors...)

Return a new selector with all selectors in $selectors appended one another as though they had been nested in the stylesheet as $selector1 { &$selector2 { ... } }.

Examples:

selector-append(".foo", ".bar", ".baz") => .foo.bar.baz
selector-append(".a .foo", ".b .bar") => "a .foo.b .bar"
selector-append(".foo", "-suffix") => ".foo-suffix"

Returns A list of lists of strings representing the result of appending $selectors. This is in the same format as a selector returned by &.

Parameters:

Returns:

  • (Sass::Script::Value::List)

    A list of lists of strings representing the result of appending $selectors. This is in the same format as a selector returned by &.

Raises:

  • (ArgumentError)

    if a selector could not be appended.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2398

def selector_append(*selectors)
  if selectors.empty?
    raise ArgumentError.new("$selectors: At least one selector must be passed")
  end

  selectors.map {|sel| parse_selector(sel, :selectors)}.inject do |parent, child|
    child.members.each do |seq|
      sseq = seq.members.first
      unless sseq.is_a?(Sass::Selector::SimpleSequence)
        raise ArgumentError.new("Can't append \"#{seq}\" to \"#{parent}\"")
      end

      base = sseq.base
      case base
      when Sass::Selector::Universal
        raise ArgumentError.new("Can't append \"#{seq}\" to \"#{parent}\"")
      when Sass::Selector::Element
        unless base.namespace.nil?
          raise ArgumentError.new("Can't append \"#{seq}\" to \"#{parent}\"")
        end
        sseq.members[0] = Sass::Selector::Parent.new(base.name)
      else
        sseq.members.unshift Sass::Selector::Parent.new
      end
    end
    child.resolve_parent_refs(parent)
  end.to_sass_script
end

- (Sass::Script::Value::List) selector_extend($selector, $extendee, $extender)

Returns a new version of $selector with $extendee extended with $extender. This works just like the result of

$selector { ... }
$extender { @extend $extendee }

Examples:

selector-extend(".a .b", ".b", ".foo .bar") => .a .b, .a .foo .bar, .foo .a .bar

Returns A list of lists of strings representing the result of the extension. This is in the same format as a selector returned by &.

Parameters:

Returns:

  • (Sass::Script::Value::List)

    A list of lists of strings representing the result of the extension. This is in the same format as a selector returned by &.

Raises:

  • (ArgumentError)

    if the extension fails



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2455

def selector_extend(selector, extendee, extender)
  selector = parse_selector(selector, :selector)
  extendee = parse_selector(extendee, :extendee)
  extender = parse_selector(extender, :extender)

  extends = Sass::Util::SubsetMap.new
  begin
    extender.populate_extends(extends, extendee)
    selector.do_extend(extends).to_sass_script
  rescue Sass::SyntaxError => e
    raise ArgumentError.new(e.to_s)
  end
end

- (Sass::Script::Value::List) selector_nest($selectors...)

Return a new selector with all selectors in $selectors nested beneath one another as though they had been nested in the stylesheet as $selector1 { $selector2 { ... } }.

Unlike most selector functions, selector-nest allows the parent selector & to be used in any selector but the first.

Examples:

selector-nest(".foo", ".bar", ".baz") => .foo .bar .baz
selector-nest(".a .foo", ".b .bar") => .a .foo .b .bar
selector-nest(".foo", "&.bar") => .foo.bar

Returns A list of lists of strings representing the result of nesting $selectors. This is in the same format as a selector returned by &.

Parameters:

Returns:

  • (Sass::Script::Value::List)

    A list of lists of strings representing the result of nesting $selectors. This is in the same format as a selector returned by &.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2368

def selector_nest(*selectors)
  if selectors.empty?
    raise ArgumentError.new("$selectors: At least one selector must be passed")
  end

  parsed = [parse_selector(selectors.first, :selectors)]
  parsed += selectors[1..-1].map {|sel| parse_selector(sel, :selectors, !!:parse_parent_ref)}
  parsed.inject {|result, child| child.resolve_parent_refs(result)}.to_sass_script
end

- (Sass::Script::Value::List) selector_parse($selector)

Parses a user-provided selector into a list of lists of strings as returned by &.

Examples:

selector-parse(".foo .bar, .baz .bang") => ('.foo' '.bar', '.baz' '.bang')

Returns A list of lists of strings representing $selector. This is in the same format as a selector returned by &.

Parameters:

Returns:

  • (Sass::Script::Value::List)

    A list of lists of strings representing $selector. This is in the same format as a selector returned by &.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2342

def selector_parse(selector)
  parse_selector(selector, :selector).to_sass_script
end

- (Sass::Script::Value::List) selector_replace($selector, $original, $replacement)

Replaces all instances of $original with $replacement in $selector

This works by using @extend and throwing away the original selector. This means that it can be used to do very advanced replacements; see the examples below.

Examples:

selector-replace(".foo .bar", ".bar", ".baz") => ".foo .baz"
selector-replace(".foo.bar.baz", ".foo.baz", ".qux") => ".bar.qux"

Returns A list of lists of strings representing the result of the extension. This is in the same format as a selector returned by &.

Parameters:

Returns:

  • (Sass::Script::Value::List)

    A list of lists of strings representing the result of the extension. This is in the same format as a selector returned by &.

Raises:

  • (ArgumentError)

    if the replacement fails



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2498

def selector_replace(selector, original, replacement)
  selector = parse_selector(selector, :selector)
  original = parse_selector(original, :original)
  replacement = parse_selector(replacement, :replacement)

  extends = Sass::Util::SubsetMap.new
  begin
    replacement.populate_extends(extends, original)
    selector.do_extend(extends, [], !!:replace).to_sass_script
  rescue Sass::SyntaxError => e
    raise ArgumentError.new(e.to_s)
  end
end

- (Sass::Script::Value::List, Sass::Script::Value::Null) selector_unify($selector1, $selector2)

Unifies two selectors into a single selector that matches only elements matched by both input selectors. Returns null if there is no such selector.

Like the selector unification done for @extend, this doesn’t guarantee that the output selector will match all elements matched by both input selectors. For example, if .a .b is unified with .x .y, .a .x .b.y, .x .a .b.y will be returned, but .a.x .b.y will not. This avoids exponential output size while matching all elements that are likely to exist in practice.

Examples:

selector-unify(".a", ".b") => .a.b
selector-unify(".a .b", ".x .y") => .a .x .b.y, .x .a .b.y
selector-unify(".a.b", ".b.c") => .a.b.c
selector-unify("#a", "#b") => null

Returns A list of lists of strings representing the result of the unification, or null if no unification exists. This is in the same format as a selector returned by &.

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2544

def selector_unify(selector1, selector2)
  selector1 = parse_selector(selector1, :selector1)
  selector2 = parse_selector(selector2, :selector2)
  return null unless (unified = selector1.unify(selector2))
  unified.to_sass_script
end

- (Sass::Script::Value::List) set

Return a new list, based on the list provided, but with the nth element changed to the value given.

Note that unlike some languages, the first item in a Sass list is number 1, the second number 2, and so forth.

Negative index values address elements in reverse order, starting with the last element in the list.

Examples:

set-nth($list: 10px 20px 30px, $n: 2, $value: -20px) => 10px -20px 30px

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $n isn’t an integer between 1 and the length of $list



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1816

def set_nth(list, n, value)
  assert_type n, :Number, :n
  Sass::Script::Value::List.assert_valid_index(list, n)
  index = n.to_i > 0 ? n.to_i - 1 : n.to_i
  new_list = list.to_a.dup
  new_list[index] = value
  Sass::Script::Value::List.new(new_list, list.separator)
end

- (Sass::Script::Value::List) simple_selectors($selector)

Returns the simple selectors that comprise the compound selector $selector.

Note that $selector must be a compound selector. That means it cannot contain commas or spaces. It also means that unlike other selector functions, this takes only strings, not lists.

Examples:

simple-selectors(".foo.bar") => ".foo", ".bar"
simple-selectors(".foo.bar.baz") => ".foo", ".bar", ".baz"

Returns A list of simple selectors in the compound selector.

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2571

def simple_selectors(selector)
  selector = parse_compound_selector(selector, :selector)
  list(selector.members.map {|simple| unquoted_string(simple.to_s)}, :comma)
end

- (Sass::Script::Value::Number, Sass::Script::Value::Null) str_index($string, $substring)

Returns the index of the first occurrence of $substring in $string. If there is no such occurrence, returns null.

Note that unlike some languages, the first character in a Sass string is number 1, the second number 2, and so forth.

Examples:

str-index(abcd, a)  => 1
str-index(abcd, ab) => 1
str-index(abcd, X)  => null
str-index(abcd, c)  => 3

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1491

def str_index(string, substring)
  assert_type string, :String, :string
  assert_type substring, :String, :substring
  index = string.value.index(substring.value)
  index ? number(index + 1) : null
end

- (Sass::Script::Value::String) str_insert($string, $insert, $index)

Inserts $insert into $string at $index.

Note that unlike some languages, the first character in a Sass string is number 1, the second number 2, and so forth.

Examples:

str-insert("abcd", "X", 1) => "Xabcd"
str-insert("abcd", "X", 4) => "abcXd"
str-insert("abcd", "X", 5) => "abcdX"

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1459

def str_insert(original, insert, index)
  assert_type original, :String, :string
  assert_type insert, :String, :insert
  assert_integer index, :index
  assert_unit index, nil, :index
  insertion_point = if index.value > 0
                      [index.value - 1, original.value.size].min
                    else
                      [index.value, -original.value.size - 1].max
                    end
  result = original.value.dup.insert(insertion_point, insert.value)
  Sass::Script::Value::String.new(result, original.type)
end

- (Sass::Script::Value::Number) str_length($string)

Returns the number of characters in a string.

Examples:

str-length("foo") => 3

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $string isn’t a string



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1433

def str_length(string)
  assert_type string, :String, :string
  number(string.value.size)
end

- (Sass::Script::Value::String) str_slice($string, $start-at, $end-at:-1)

Extracts a substring from $string. The substring will begin at index $start-at and ends at index $end-at.

Note that unlike some languages, the first character in a Sass string is number 1, the second number 2, and so forth.

Examples:

str-slice("abcd", 2, 3)   => "bc"
str-slice("abcd", 2)      => "bcd"
str-slice("abcd", -3, -2) => "bc"
str-slice("abcd", 2, -2)  => "bc"

Returns The substring. This will be quoted if and only if $string was quoted

Parameters:

  • $start-at (Sass::Script::Value::Number)

    The index of the first character of the substring. If this is negative, it counts from the end of $string

  • $end-before (Sass::Script::Value::Number)

    The index of the last character of the substring. If this is negative, it counts from the end of $string. Defaults to -1

Returns:

Raises:

  • (ArgumentError)

    if any parameter is the wrong type



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1521

def str_slice(string, start_at, end_at = nil)
  assert_type string, :String, :string
  assert_unit start_at, nil, "start-at"

  end_at = number(-1) if end_at.nil?
  assert_unit end_at, nil, "end-at"

  return Sass::Script::Value::String.new("", string.type) if end_at.value == 0
  s = start_at.value > 0 ? start_at.value - 1 : start_at.value
  e = end_at.value > 0 ? end_at.value - 1 : end_at.value
  s = string.value.length + s if s < 0
  s = 0 if s < 0
  e = string.value.length + e if e < 0
  e = 0 if s < 0
  extracted = string.value.slice(s..e)
  Sass::Script::Value::String.new(extracted || "", string.type)
end

- (Sass::Script::Value::String) to_lower_case($string)

Convert a string to lower case,

Examples:

to-lower-case(ABCD) => abcd

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $string isn’t a string



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1565

def to_lower_case(string)
  assert_type string, :String, :string
  Sass::Script::Value::String.new(string.value.downcase, string.type)
end

- (Sass::Script::Value::String) to_upper_case($string)

Converts a string to upper case.

Examples:

to-upper-case(abcd) => ABCD

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $string isn’t a string



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1550

def to_upper_case(string)
  assert_type string, :String, :string
  Sass::Script::Value::String.new(string.value.upcase, string.type)
end

- (Sass::Script::Value::Color) transparentize($color, $amount) Also known as: fade_out

Makes a color more transparent. Takes a color and a number between 0 and 1, and returns a color with the opacity decreased by that amount.

Examples:

transparentize(rgba(0, 0, 0, 0.5), 0.1) => rgba(0, 0, 0, 0.4)
transparentize(rgba(0, 0, 0, 0.8), 0.2) => rgba(0, 0, 0, 0.6)

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $amount is out of bounds, or either parameter is the wrong type

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 934

def transparentize(color, amount)
  _adjust(color, amount, :alpha, 0..1, :-)
end

- (Sass::Script::Value::String) type_of($value)

Returns the type of a value.

Examples:

type-of(100px)  => number
type-of(asdf)   => string
type-of("asdf") => string
type-of(true)   => bool
type-of(#fff)   => color
type-of(blue)   => color

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1584

def type_of(value)
  identifier(value.class.name.gsub(/Sass::Script::Value::/, '').downcase)
end

- (Sass::Script::Value::String) unique_id

Returns a unique CSS identifier. The identifier is returned as an unquoted string. The identifier returned is only guaranteed to be unique within the scope of a single Sass run.



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2147

def unique_id
  generator = Sass::Script::Functions.random_number_generator
  Thread.current[:sass_last_unique_id] ||= generator.rand(36**8)
  # avoid the temptation of trying to guess the next unique value.
  value = (Thread.current[:sass_last_unique_id] += (generator.rand(10) + 1))
  # the u makes this a legal identifier if it would otherwise start with a number.
  identifier("u" + value.to_s(36).rjust(8, '0'))
end

- (Sass::Script::Value::String) unit($number)

Returns the unit(s) associated with a number. Complex units are sorted in alphabetical order by numerator and denominator.

Examples:

unit(100) => ""
unit(100px) => "px"
unit(3em) => "em"
unit(10px * 5em) => "em*px"
unit(10px * 5em / 30cm / 1rem) => "em*px/cm*rem"

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1634

def unit(number)
  assert_type number, :Number, :number
  quoted_string(number.unit_str)
end

- (Sass::Script::Value::Bool) unitless($number)

Returns whether a number has units.

Examples:

unitless(100) => true
unitless(100px) => false

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $number isn’t a number



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1649

def unitless(number)
  assert_type number, :Number, :number
  bool(number.unitless?)
end

- (Sass::Script::Value::String) unquote($string)

Removes quotes from a string. If the string is already unquoted, this will return it unmodified.

Examples:

unquote("foo") => foo
unquote(foo) => foo

Parameters:

Returns:

Raises:

  • (ArgumentError)

    if $string isn’t a string

See Also:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1395

def unquote(string)
  if string.is_a?(Sass::Script::Value::String) && string.type != :identifier
    identifier(string.value)
  else
    string
  end
end

- (Sass::Script::Value::Bool) variable_exists($name)

Check whether a variable with the given name exists in the current scope or in the global scope.

Examples:

$a-false-value: false;
variable-exists(a-false-value) => true

variable-exists(nonexistent) => false

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 2227

def variable_exists(name)
  assert_type name, :String, :name
  bool(environment.caller.var(name.value))
end

- (Sass::Script::Value::List) zip($lists...)

Combines several lists into a single multidimensional list. The nth value of the resulting list is a space separated list of the source lists’ nth values.

The length of the resulting list is the length of the shortest list.

Examples:

zip(1px 1px 3px, solid dashed solid, red green blue)
=> 1px solid red, 1px dashed green, 3px solid blue

Parameters:

Returns:



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# File '/home/nweiz/code/sass-site/.sass/lib/sass/script/functions.rb', line 1937

def zip(*lists)
  length = nil
  values = []
  lists.each do |list|
    array = list.to_a
    values << array.dup
    length = length.nil? ? array.length : [length, array.length].min
  end
  values.each do |value|
    value.slice!(length)
  end
  new_list_value = values.first.zip(*values[1..-1])
  list(new_list_value.map {|list| list(list, :space)}, :comma)
end