Class: Sass::Script::Number

Inherits:
Literal show all
Defined in:
lib/sass/script/number.rb

Overview

A SassScript object representing a number. SassScript numbers can have decimal values, and can also have units. For example, 12, 1px, and 10.45em are all valid values.

Numbers can also have more complex units, such as 1px*em/in. These cannot be inputted directly in Sass code at the moment.

Constant Summary collapse

PRECISION =

The precision with which numbers will be printed to CSS files. For example, if this is 1000.0, 3.1415926 will be printed as 3.142.

1000.0
CONVERTABLE_UNITS =

A hash of unit names to their index in the conversion table

{"in" => 0,        "cm" => 1,    "pc" => 2,    "mm" => 3,   "pt" => 4}
CONVERSION_TABLE =

in

[[ 1,                2.54,         6,            25.4,        72        ], # in
[ nil,              1,            2.36220473,   10,          28.3464567], # cm
[ nil,              nil,          1,            4.23333333,  12        ], # pc
[ nil,              nil,          nil,          1,           2.83464567], # mm
[ nil,              nil,          nil,          nil,         1         ]]

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Literal

#==, #and, #assert_int!, #comma, #concat, #neq, #or, #perform, #to_bool, #unary_div, #unary_not

Methods inherited from Node

#perform

Constructor Details

#initialize(value, numerator_units = [], denominator_units = []) ⇒ Number

Returns a new instance of Number.

Parameters:



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# File 'lib/sass/script/number.rb', line 36

def initialize(value, numerator_units = [], denominator_units = [])
  super(value)
  @numerator_units = numerator_units
  @denominator_units = denominator_units
  normalize!
end

Instance Attribute Details

#denominator_units ⇒ Array<String> (readonly)

A list of units in the denominator of the number. For example, 1px*em/in*cm would return ["in", "cm"]

Returns:



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# File 'lib/sass/script/number.rb', line 26

def denominator_units
  @denominator_units
end

#numerator_units ⇒ Array<String> (readonly)

A list of units in the numerator of the number. For example, 1px*em/in*cm would return ["px", "em"]

Returns:



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# File 'lib/sass/script/number.rb', line 21

def numerator_units
  @numerator_units
end

#value ⇒ Numeric (readonly)

The Ruby value of the number.

Returns:

  • (Numeric) 


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# File 'lib/sass/script/number.rb', line 16

def value
  @value
end

Instance Method Details

#coerce(num_units, den_units) ⇒ Number

Returns this number converted to other units. The conversion takes into account the relationship between e.g. mm and cm, as well as between e.g. in and cm.

If this number has no units, it will simply return itself with the given units.

An incompatible coercion, e.g. between px and cm, will raise an error.

Parameters:

Returns:

  • (Number) —

    The number with the new units

Raises:



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# File 'lib/sass/script/number.rb', line 278

def coerce(num_units, den_units)
  Number.new(if unitless?
               self.value
             else
               self.value * coercion_factor(self.numerator_units, num_units) /
                 coercion_factor(self.denominator_units, den_units)
             end, num_units, den_units)
end

#coercion_factor(from_units, to_units) ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 309

def coercion_factor(from_units, to_units)
  # get a list of unmatched units
  from_units, to_units = sans_common_units(from_units, to_units)

  if from_units.size != to_units.size || !convertable?(from_units | to_units)
    raise Sass::UnitConversionError.new("Incompatible units: '#{from_units.join('*')}' and '#{to_units.join('*')}'.")
  end

  from_units.zip(to_units).inject(1) {|m,p| m * conversion_factor(p[0], p[1]) }
end

#compute_units(this, other, operation) ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 320

def compute_units(this, other, operation)
  case operation
  when :*
    [this.numerator_units + other.numerator_units, this.denominator_units + other.denominator_units]
  when :/
    [this.numerator_units + other.denominator_units, this.denominator_units + other.numerator_units]
  else  
    [this.numerator_units, this.denominator_units]
  end
end

#conversion_factor(from_unit, to_unit) ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 361

def conversion_factor(from_unit, to_unit)
  res = CONVERSION_TABLE[CONVERTABLE_UNITS[from_unit]][CONVERTABLE_UNITS[to_unit]]
  return 1.0 / conversion_factor(to_unit, from_unit) if res.nil?
  res
end

#convertable?(units) ⇒ Boolean (protected)

Returns:

  • (Boolean) 


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# File 'lib/sass/script/number.rb', line 367

def convertable?(units)
  Array(units).all?(&CONVERTABLE_UNITS.method(:include?))
end

#div(other) ⇒ Literal

The SassScript / operation. Its functionality depends on the type of its argument:

Sass::Script::Number : Divides this number by the other, converting units appropriately.

Literal : See Literal#div.

Parameters:

  • other (Literal) —

    The right-hand side of the operator

Returns:

  • (Literal) —

    The result of the operation



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# File 'lib/sass/script/number.rb', line 128

def div(other)
  if other.is_a? Number
    operate(other, :/)
  else
    super
  end
end

#eq(other) ⇒ Boolean

The SassScript == operation.

Parameters:

  • other (Literal) —

    The right-hand side of the operator

Returns:

  • (Boolean) —

    Whether this number is equal to the other object



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# File 'lib/sass/script/number.rb', line 157

def eq(other)
  return Sass::Script::Bool.new(false) unless other.is_a?(Sass::Script::Number)
  this = self
  begin
    if unitless?
      this = this.coerce(other.numerator_units, other.denominator_units)
    else
      other = other.coerce(numerator_units, denominator_units)
    end
  rescue Sass::UnitConversionError
    return Sass::Script::Bool.new(false)
  end

  Sass::Script::Bool.new(this.value == other.value)
end

#gt(other) ⇒ Boolean

The SassScript > operation.

Parameters:

  • other (Number) —

    The right-hand side of the operator

Returns:

  • (Boolean) —

    Whether this number is greater than the other

Raises:

  • (NoMethodError) —

    if other is an invalid type



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# File 'lib/sass/script/number.rb', line 178

def gt(other)
  raise NoMethodError.new(nil, :gt) unless other.is_a?(Number)
  operate(other, :>)
end

#gte(other) ⇒ Boolean

The SassScript >= operation.

Parameters:

  • other (Number) —

    The right-hand side of the operator

Returns:

  • (Boolean) —

    Whether this number is greater than or equal to the other

Raises:

  • (NoMethodError) —

    if other is an invalid type



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# File 'lib/sass/script/number.rb', line 188

def gte(other)
  raise NoMethodError.new(nil, :gte) unless other.is_a?(Number)
  operate(other, :>=)
end

#inspect ⇒ String

Returns a readable representation of this number.

This representation is valid CSS (and valid SassScript) as long as there is only one unit.

Returns:

  • (String) —

    The representation



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# File 'lib/sass/script/number.rb', line 227

def inspect
  value =
    if self.value.is_a?(Float) && (self.value.infinite? || self.value.nan?)
      self.value
    elsif int?
      self.value.to_i
    else
      (self.value * PRECISION).round / PRECISION
    end
  "#{value}#{unit_str}"
end

#int? ⇒ Boolean

Returns Whether or not this number is an integer.

Returns:

  • (Boolean) —

    Whether or not this number is an integer.



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# File 'lib/sass/script/number.rb', line 247

def int?
  value % 1 == 0.0
end

#legal_units? ⇒ Boolean

Returns Whether or not this number has units that can be represented in CSS (that is, zero or one #numerator_units).

Returns:

  • (Boolean) —

    Whether or not this number has units that can be represented in CSS (that is, zero or one #numerator_units).



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# File 'lib/sass/script/number.rb', line 258

def legal_units?
  (numerator_units.empty? || numerator_units.size == 1) && denominator_units.empty?
end

#lt(other) ⇒ Boolean

The SassScript < operation.

Parameters:

  • other (Number) —

    The right-hand side of the operator

Returns:

  • (Boolean) —

    Whether this number is less than the other

Raises:

  • (NoMethodError) —

    if other is an invalid type



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# File 'lib/sass/script/number.rb', line 198

def lt(other)
  raise NoMethodError.new(nil, :lt) unless other.is_a?(Number)
  operate(other, :<)
end

#lte(other) ⇒ Boolean

The SassScript <= operation.

Parameters:

  • other (Number) —

    The right-hand side of the operator

Returns:

  • (Boolean) —

    Whether this number is less than or equal to the other

Raises:

  • (NoMethodError) —

    if other is an invalid type



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# File 'lib/sass/script/number.rb', line 208

def lte(other)
  raise NoMethodError.new(nil, :lte) unless other.is_a?(Number)
  operate(other, :<=)
end

#minus(other) ⇒ Literal

The SassScript binary - operation (e.g. !a - !b). Its functionality depends on the type of its argument:

Sass::Script::Number : Subtracts this number from the other, converting units if possible.

Literal : See Literal#minus.

Parameters:

  • other (Literal) —

    The right-hand side of the operator

Returns:

  • (Literal) —

    The result of the operation

Raises:



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# File 'lib/sass/script/number.rb', line 80

def minus(other)
  if other.is_a? Number
    operate(other, :-)
  else
    super
  end
end

#mod(other) ⇒ Number

The SassScript % operation.

Parameters:

  • other (Number) —

    The right-hand side of the operator

Returns:

  • (Number) —

    This number modulo the other

Raises:



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# File 'lib/sass/script/number.rb', line 142

def mod(other)
  if other.is_a?(Number)
    unless other.unitless?
      raise Sass::UnitConversionError.new("Cannot modulo by a number with units: #{other.inspect}.")
    end
    operate(other, :%)
  else
    raise NoMethodError.new(nil, :mod)
  end
end

#normalize! ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 340

def normalize!
  return if unitless?
  @numerator_units, @denominator_units = sans_common_units(numerator_units, denominator_units)

  @denominator_units.each_with_index do |d, i|
    if convertable?(d) && (u = @numerator_units.detect(&method(:convertable?)))
      @value /= conversion_factor(d, u)
      @denominator_units.delete_at(i)
      @numerator_units.delete_at(@numerator_units.index(u))
    end
  end
end

#operate(other, operation) ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 289

def operate(other, operation)
  this = self
  if [:+, :-, :<=, :<, :>, :>=].include?(operation)
    if unitless?
      this = this.coerce(other.numerator_units, other.denominator_units)
    else
      other = other.coerce(numerator_units, denominator_units)
    end
  end
  # avoid integer division
  value = (:/ == operation) ? this.value.to_f : this.value
  result = value.send(operation, other.value)

  if result.is_a?(Numeric)
    Number.new(result, *compute_units(this, other, operation))
  else # Boolean op
    Bool.new(result)
  end
end

#plus(other) ⇒ Literal

The SassScript + operation. Its functionality depends on the type of its argument:

Sass::Script::Number : Adds the two numbers together, converting units if possible.

Color : Adds this number to each of the RGB color channels.

Literal : See Literal#plus.

Parameters:

  • other (Literal) —

    The right-hand side of the operator

Returns:

  • (Literal) —

    The result of the operation

Raises:



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# File 'lib/sass/script/number.rb', line 58

def plus(other)
  if other.is_a? Number
    operate(other, :+)
  elsif other.is_a?(Color)
    other.plus(self)
  else
    super
  end
end

#sans_common_units(units1, units2) ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 371

def sans_common_units(units1, units2)
  units2 = units2.dup
  # Can't just use -, because we want px*px to coerce properly to px*mm
  return units1.map do |u|
    next u unless j = units2.index(u)
    units2.delete_at(j)
    nil
  end.compact, units2
end

#times(other) ⇒ Number, Color

The SassScript * operation. Its functionality depends on the type of its argument:

Sass::Script::Number : Multiplies the two numbers together, converting units appropriately.

Color : Multiplies each of the RGB color channels by this number.

Parameters:

  • other (Number, Color) —

    The right-hand side of the operator

Returns:

Raises:

  • (NoMethodError) —

    if other is an invalid type



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# File 'lib/sass/script/number.rb', line 107

def times(other)
  if other.is_a? Number
    self.operate(other, :*)
  elsif other.is_a? Color
    other.times(self)
  else
    raise NoMethodError.new(nil, :times)
  end
end

#to_i ⇒ Fixnum

Returns The integer value of the number.

Returns:

  • (Fixnum) —

    The integer value of the number

Raises:



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# File 'lib/sass/script/number.rb', line 241

def to_i
  super unless int?
  return value
end

#to_s ⇒ String

Returns The CSS representation of this number.

Returns:

  • (String) —

    The CSS representation of this number

Raises:

  • (Sass::SyntaxError) —

    if this number has units that can't be used in CSS (e.g. px*in)



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# File 'lib/sass/script/number.rb', line 216

def to_s
  raise Sass::SyntaxError.new("#{inspect} isn't a valid CSS value.") unless legal_units?
  inspect
end

#unary_minus ⇒ Number

The SassScript unary - operation (e.g. -!a).

Returns:

  • (Number) —

    The negative value of this number



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# File 'lib/sass/script/number.rb', line 91

def unary_minus
  Number.new(-value, numerator_units, denominator_units)
end

#unit_str ⇒ Object (protected) 



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# File 'lib/sass/script/number.rb', line 331

def unit_str
  rv = numerator_units.join("*")
  if denominator_units.any?
    rv << "/"
    rv << denominator_units.join("*")
  end
  rv
end

#unitless? ⇒ Boolean

Returns Whether or not this number has no units.

Returns:

  • (Boolean) —

    Whether or not this number has no units.



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# File 'lib/sass/script/number.rb', line 252

def unitless?
  numerator_units.empty? && denominator_units.empty?
end