class Sprockets::SassProcessor

def self.cache_key 

def self.cache_key
  instance.cache_key
end

def self.call(input) 

def self.call(input)
  instance.call(input)
end

def self.instance

Returns SassProcessor object.

Public: Return singleton instance with default options. 
def self.instance
  @instance ||= new
end

def self.syntax

may override it.
Internal: Defines default sass syntax to use. Exposed so the ScssProcessor 
def self.syntax
  :sass
end

def build_cache_store(input, version)

Sprockets cache.
Override this method if you need to use a different cache than the

version - the cache version.
input - the input hash.

Public: Build the cache store to be used by the Sass engine. 
def build_cache_store(input, version)
  CacheStore.new(input[:cache], version)
end

def call(input) 

def call(input)
  context = input[:environment].context_class.new(input)
  engine_options = merge_options({
    filename: input[:filename],
    syntax: self.class.syntax,
    cache_store: build_cache_store(input, @cache_version),
    load_paths: context.environment.paths.map { |p| @importer_class.new(p.to_s) },
    importer: @importer_class.new(Pathname.new(context.filename).to_s),
    sprockets: {
      context: context,
      environment: input[:environment],
      dependencies: context.metadata[:dependencies]
    }
  })
  engine = Autoload::Sass::Engine.new(input[:data], engine_options)
  css, map = Utils.module_include(Autoload::Sass::Script::Functions, @functions) do
    engine.render_with_sourcemap('')
  end
  css = css.sub("\n/*# sourceMappingURL= */\n", '')
  map = SourceMapUtils.combine_source_maps(
    input[:metadata][:map],
    SourceMapUtils.decode_json_source_map(map.to_json(css_uri: '', type: :inline))["mappings"]
  )
  # Track all imported files
  sass_dependencies = Set.new([input[:filename]])
  engine.dependencies.map do |dependency|
    sass_dependencies << dependency.options[:filename]
    context.metadata[:dependencies] << URIUtils.build_file_digest_uri(dependency.options[:filename])
  end
  context.metadata.merge(data: css, sass_dependencies: sass_dependencies, map: map)
end

def initialize(options = {}, &block)


change after code changes are made to Sass Functions.
cache_version - String custom cache version. Used to force a cache
options - Hash

Public: Initialize template with custom options. 
def initialize(options = {}, &block)
  @cache_version = options[:cache_version]
  @cache_key = "#{self.class.name}:#{VERSION}:#{Autoload::Sass::VERSION}:#{@cache_version}".freeze
  @importer_class = options[:importer] || Sass::Importers::Filesystem
  @sass_config = options[:sass_config] || {}
  @functions = Module.new do
    include Functions
    include options[:functions] if options[:functions]
    class_eval(&block) if block_given?
  end
end

def merge_options(options) 

def merge_options(options)
  defaults = @sass_config.dup
  if load_paths = defaults.delete(:load_paths)
    options[:load_paths] += load_paths
  end
  options.merge!(defaults)
  options
end