class Sass::Script::Value::Number
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.
Constants
- CONVERSION_TABLE
A two-dimensional hash from two units to the conversion ratio between them. Multiply ‘X` by `CONVERSION_TABLE[Y]` to convert it to `Y`.
- MUTUALLY_CONVERTIBLE
A hash from each known unit to the set of units that it’s mutually convertible with.
- NO_UNITS
Used so we don’t allocate two new arrays for each new number.
- OPERATIONS
Attributes
A list of units in the denominator of the number. For example, ‘1px*em/in*cm` would return `[“in”, “cm”]` @return [Array<String>]
A list of units in the numerator of the number. For example, ‘1px*em/in*cm` would return `[“px”, “em”]` @return [Array<String>]
The original representation of this number. For example, although the result of ‘1px/2px` is `0.5`, the value of `#original` is `“1px/2px”`.
This is only non-nil when the original value should be used as the CSS
value, as in ‘font: 1px/2px`.
@return [Boolean, nil]
The Ruby value of the number.
@return [Numeric]
Public Class Methods
Used in checking equality of floating point numbers. Any numbers within an ‘epsilon` of each other are considered functionally equal. The value for epsilon is one tenth of the current numeric precision.
# File lib/sass/script/value/number.rb, line 60 def self.epsilon Thread.current[:sass_numeric_epsilon] ||= 1 / (precision_factor * 10) end
@param value [Numeric] The value of the number @param numerator_units
[::String, Array<::String>] See {#numerator_units} @param denominator_units
[::String, Array<::String>] See {#denominator_units}
Sass::Script::Value::Base::new
# File lib/sass/script/value/number.rb, line 70 def initialize(value, numerator_units = NO_UNITS, denominator_units = NO_UNITS) numerator_units = [numerator_units] if numerator_units.is_a?(::String) denominator_units = [denominator_units] if denominator_units.is_a?(::String) super(value) @numerator_units = numerator_units @denominator_units = denominator_units @options = nil normalize! end
# File lib/sass/script/value/number.rb, line 36 def self.precision Thread.current[:sass_numeric_precision] || Thread.main[:sass_numeric_precision] || 10 end
Sets the number of digits of precision For example, if this is ‘3`, `3.1415926` will be printed as `3.142`. The numeric precision is stored as a thread local for thread safety reasons. To set for all threads, be sure to set the precision on the main thread.
# File lib/sass/script/value/number.rb, line 45 def self.precision=(digits) Thread.current[:sass_numeric_precision] = digits.round Thread.current[:sass_numeric_precision_factor] = nil Thread.current[:sass_numeric_epsilon] = nil end
the precision factor used in numeric output it is derived from the ‘precision` method.
# File lib/sass/script/value/number.rb, line 53 def self.precision_factor Thread.current[:sass_numeric_precision_factor] ||= 10.0**precision end
Private Class Methods
Checks whether two numbers are within an epsilon of each other. @return [Boolean]
# File lib/sass/script/value/number.rb, line 408 def self.basically_equal?(num1, num2) (num1 - num2).abs < epsilon end
@private
# File lib/sass/script/value/number.rb, line 413 def self.round(num) if num.is_a?(Float) && (num.infinite? || num.nan?) num elsif basically_equal?(num % 1, 0.0) num.round else ((num * precision_factor).round / precision_factor).to_f end end
Public Instance Methods
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.
@param num_units [Array<String>] The numerator units to coerce this number into.
See {\#numerator\_units}
@param den_units [Array<String>] The denominator units to coerce this number into.
See {\#denominator\_units}
@return [Number] The number with the new units @raise [Sass::UnitConversionError] if the given units are incompatible with the number’s
current units
# File lib/sass/script/value/number.rb, line 367 def coerce(num_units, den_units) Number.new(if unitless? value else value * coercion_factor(@numerator_units, num_units) / coercion_factor(@denominator_units, den_units) end, num_units, den_units) end
@param other [Number] A number to decide if it can be compared with this number. @return [Boolean] Whether or not this number can be compared with the other.
# File lib/sass/script/value/number.rb, line 378 def comparable_to?(other) operate(other, :+) true rescue Sass::UnitConversionError false end
The SassScript ‘/` operation. Its functionality depends on the type of its argument:
{Number} : Divides this number by the other, converting units appropriately.
{Value} : See {Value::Base#div}.
@param other [Value] The right-hand side of the operator @return [Value] The result of the operation
Sass::Script::Value::Base#div
# File lib/sass/script/value/number.rb, line 172 def div(other) if other.is_a? Number res = operate(other, :/) if original && other.original res.original = "#{original}/#{other.original}" end res else super end end
The SassScript ‘==` operation.
@param other [Value] The right-hand side of the operator @return [Boolean] Whether this number is equal to the other object
# File lib/sass/script/value/number.rb, line 203 def eq(other) return Bool::FALSE unless other.is_a?(Sass::Script::Value::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 Bool::FALSE end Bool.new(basically_equal?(this.value, other.value)) end
Hash-equality works differently than ‘==` equality for numbers. Hash-equality must be transitive, so it just compares the exact value, numerator units, and denominator units.
# File lib/sass/script/value/number.rb, line 225 def eql?(other) basically_equal?(value, other.value) && numerator_units == other.numerator_units && denominator_units == other.denominator_units end
The SassScript ‘>` operation.
@param other [Number] The right-hand side of the operator @return [Boolean] Whether this number is greater than the other @raise [NoMethodError] if ‘other` is an invalid type
# File lib/sass/script/value/number.rb, line 235 def gt(other) raise NoMethodError.new(nil, :gt) unless other.is_a?(Number) operate(other, :>) end
The SassScript ‘>=` operation.
@param other [Number] The right-hand side of the operator @return [Boolean] Whether this number is greater than or equal to the other @raise [NoMethodError] if ‘other` is an invalid type
# File lib/sass/script/value/number.rb, line 245 def gte(other) raise NoMethodError.new(nil, :gte) unless other.is_a?(Number) operate(other, :>=) end
# File lib/sass/script/value/number.rb, line 218 def hash [value, numerator_units, denominator_units].hash end
Returns a readable representation of this number.
This representation is valid CSS
(and valid SassScript) as long as there is only one unit.
@return [String] The representation
# File lib/sass/script/value/number.rb, line 285 def inspect(opts = {}) return original if original value = self.class.round(self.value) str = value.to_s # Ruby will occasionally print in scientific notation if the number is # small enough. That's technically valid CSS, but it's not well-supported # and confusing. str = ("%0.#{self.class.precision}f" % value).gsub(/0*$/, '') if str.include?('e') # Sometimes numeric formatting will result in a decimal number with a trailing zero (x.0) if str =~ /(.*)\.0$/ str = $1 end # We omit a leading zero before the decimal point in compressed mode. if @options && options[:style] == :compressed str.sub!(/^(-)?0\./, '\1.') end unitless? ? str : "#{str}#{unit_str}" end
@return [Boolean] Whether or not this number is an integer.
# File lib/sass/script/value/number.rb, line 318 def int? basically_equal?(value % 1, 0.0) end
Checks whether the number has the numerator unit specified.
@example
number = Sass::Script::Value::Number.new(10, "px") number.is_unit?("px") => true number.is_unit?(nil) => false
@param unit [::String, nil] The unit the number should have or nil if the number
should be unitless.
@see Number#unitless?
The unitless? method may be more readable.
# File lib/sass/script/value/number.rb, line 337 def is_unit?(unit) if unit denominator_units.size == 0 && numerator_units.size == 1 && numerator_units.first == unit else unitless? end end
@return [Boolean] Whether or not this number has units that can be represented in CSS
(that is, zero or one \{#numerator\_units}).
# File lib/sass/script/value/number.rb, line 347 def legal_units? (@numerator_units.empty? || @numerator_units.size == 1) && @denominator_units.empty? end
The SassScript ‘<` operation.
@param other [Number] The right-hand side of the operator @return [Boolean] Whether this number is less than the other @raise [NoMethodError] if ‘other` is an invalid type
# File lib/sass/script/value/number.rb, line 255 def lt(other) raise NoMethodError.new(nil, :lt) unless other.is_a?(Number) operate(other, :<) end
The SassScript ‘<=` operation.
@param other [Number] The right-hand side of the operator @return [Boolean] Whether this number is less than or equal to the other @raise [NoMethodError] if ‘other` is an invalid type
# File lib/sass/script/value/number.rb, line 265 def lte(other) raise NoMethodError.new(nil, :lte) unless other.is_a?(Number) operate(other, :<=) end
The SassScript binary ‘-` operation (e.g. `$a - $b`). Its functionality depends on the type of its argument:
{Number} : Subtracts this number from the other, converting units if possible.
{Value} : See {Value::Base#minus}.
@param other [Value] The right-hand side of the operator @return [Value] The result of the operation @raise [Sass::UnitConversionError] if ‘other` is a number with incompatible units
Sass::Script::Value::Base#minus
# File lib/sass/script/value/number.rb, line 117 def minus(other) if other.is_a? Number operate(other, :-) else super end end
The SassScript ‘%` operation.
@param other [Number] The right-hand side of the operator @return [Number] This number modulo the other @raise [NoMethodError] if ‘other` is an invalid type @raise [Sass::UnitConversionError] if `other` has incompatible units
# File lib/sass/script/value/number.rb, line 190 def mod(other) if other.is_a?(Number) return Number.new(Float::NAN) if other.value == 0 operate(other, :%) else raise NoMethodError.new(nil, :mod) end end
The SassScript ‘+` operation. Its functionality depends on the type of its argument:
{Number} : Adds the two numbers together, converting units if possible.
{Color} : Adds this number to each of the RGB color channels.
{Value} : See {Value::Base#plus}.
@param other [Value] The right-hand side of the operator @return [Value] The result of the operation @raise [Sass::UnitConversionError] if ‘other` is a number with incompatible units
Sass::Script::Value::Base#plus
# File lib/sass/script/value/number.rb, line 95 def plus(other) if other.is_a? Number operate(other, :+) elsif other.is_a?(Color) other.plus(self) else super end end
The SassScript ‘*` operation. Its functionality depends on the type of its argument:
{Number} : Multiplies the two numbers together, converting units appropriately.
{Color} : Multiplies each of the RGB color channels by this number.
@param other [Number, Color] The right-hand side of the operator @return [Number, Color] The result of the operation @raise [NoMethodError] if ‘other` is an invalid type
# File lib/sass/script/value/number.rb, line 151 def times(other) if other.is_a? Number operate(other, :*) elsif other.is_a? Color other.times(self) else raise NoMethodError.new(nil, :times) end end
@return [Integer] The integer value of the number @raise [Sass::SyntaxError] if the number isn’t an integer
Sass::Script::Value::Base#to_i
# File lib/sass/script/value/number.rb, line 312 def to_i super unless int? value.to_i end
@return [String] The CSS
representation of this number @raise [Sass::SyntaxError] if this number has units that can’t be used in CSS
(e.g. `px*in`)
# File lib/sass/script/value/number.rb, line 273 def to_s(opts = {}) return original if original raise Sass::SyntaxError.new("#{inspect} isn't a valid CSS value.") unless legal_units? inspect end
The SassScript unary ‘-` operation (e.g. `-$a`).
@return [Number] The negative value of this number
# File lib/sass/script/value/number.rb, line 135 def unary_minus Number.new(-value, @numerator_units, @denominator_units) end
The SassScript unary ‘+` operation (e.g. `+$a`).
@return [Number] The value of this number
# File lib/sass/script/value/number.rb, line 128 def unary_plus self end
Returns a human readable representation of the units in this number. For complex units this takes the form of: numerator_unit1 * numerator_unit2 / denominator_unit1 * denominator_unit2 @return [String] a string that represents the units in this number
# File lib/sass/script/value/number.rb, line 389 def unit_str rv = @numerator_units.sort.join("*") if @denominator_units.any? rv << "/" rv << @denominator_units.sort.join("*") end rv end
@return [Boolean] Whether or not this number has no units.
# File lib/sass/script/value/number.rb, line 323 def unitless? @numerator_units.empty? && @denominator_units.empty? end
Private Instance Methods
@private @see Sass::Script::Number.basically_equal?
# File lib/sass/script/value/number.rb, line 402 def basically_equal?(num1, num2) self.class.basically_equal?(num1, num2) end
# File lib/sass/script/value/number.rb, line 445 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
# File lib/sass/script/value/number.rb, line 457 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
# File lib/sass/script/value/number.rb, line 540 def conversion_factor(from_unit, to_unit) CONVERSION_TABLE[from_unit][to_unit] end
# File lib/sass/script/value/number.rb, line 544 def convertable?(units) units = Array(units).to_set return true if units.empty? return false unless (mutually_convertible = MUTUALLY_CONVERTIBLE[units.first]) units.subset?(mutually_convertible) end
# File lib/sass/script/value/number.rb, line 470 def normalize! return if unitless? @numerator_units, @denominator_units = sans_common_units(@numerator_units, @denominator_units) @denominator_units.each_with_index do |d, i| next unless convertable?(d) && (u = @numerator_units.find {|n| convertable?([n, d])}) @value /= conversion_factor(d, u) @denominator_units.delete_at(i) @numerator_units.delete_at(@numerator_units.index(u)) end end
# File lib/sass/script/value/number.rb, line 425 def operate(other, operation) this = self if OPERATIONS.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
# File lib/sass/script/value/number.rb, line 551 def sans_common_units(units1, units2) units2 = units2.dup # Can't just use -, because we want px*px to coerce properly to px*mm units1 = units1.map do |u| j = units2.index(u) next u unless j units2.delete_at(j) nil end units1.compact! return units1, units2 end