The lexical environment for SassScript. This keeps track of variable, mixin, and function definitions.
A new environment is created for each level of Sass nesting. This allows variables to be lexically scoped. The new environment refers to the environment in the upper scope, so it has access to variables defined in enclosing scopes, but new variables are defined locally.
Environment also keeps track of the {Engine} options so that they can be made available to {Sass::Script::Functions}.
The enclosing environment, or nil if this is the global environment.
@return [Environment]
@param parent [Environment] See {#parent}
# File lib/sass/environment.rb, line 24 def initialize(parent = nil) @parent = parent unless parent @stack = [] @mixins_in_use = Set.new @files_in_use = Set.new end end
A set of names of files currently present in the stack.
@return [Set<String>] The filenames.
# File lib/sass/environment.rb, line 99 def files_in_use @files_in_use ||= @parent.files_in_use end
A set of names of mixins currently present in the stack.
@return [Set<String>] The mixin names.
# File lib/sass/environment.rb, line 92 def mixins_in_use @mixins_in_use ||= @parent.mixins_in_use end
The options hash. See {file:SASS_REFERENCE.md#sass_options the Sass options documentation}.
@return [{Symbol => Object}]
# File lib/sass/environment.rb, line 37 def options @options || parent_options || {} end
Pop a stack frame from the mixin/include stack.
# File lib/sass/environment.rb, line 75 def pop_frame pop_and_unuse if stack.last && stack.last[:prepared] pop_and_unuse end
Like {#push_frame}, but next time a stack frame is pushed, it will be merged with this frame.
@param frame_info [{Symbol => Object}] Same as for {#push_frame}.
# File lib/sass/environment.rb, line 70 def prepare_frame(frame_info) push_frame(frame_info.merge(:prepared => true)) end
Push a new stack frame onto the mixin/include stack.
@param frame_info [{Symbol => Object}]
Frame information has the following keys: `:filename` : The name of the file in which the lexical scope changed. `:mixin` : The name of the mixin in which the lexical scope changed, or `nil` if it wasn't within in a mixin. `:line` : The line of the file on which the lexical scope changed. Never nil.
# File lib/sass/environment.rb, line 55 def push_frame(frame_info) top_of_stack = stack.last if top_of_stack && top_of_stack.delete(:prepared) top_of_stack.merge!(frame_info) else stack.push(top_of_stack = frame_info) end mixins_in_use << top_of_stack[:mixin] if top_of_stack[:mixin] files_in_use << top_of_stack[:filename] if top_of_stack[:filename] end
A list of stack frames in the mixin/include stack. The last element in the list is the most deeply-nested frame.
@return [Array<{Symbol => Object}>] The stack frames,
of the form passed to \{#push\_frame}.
# File lib/sass/environment.rb, line 85 def stack @stack ||= @parent.stack end
# File lib/sass/environment.rb, line 103 def stack_trace trace = [] stack.reverse.each_with_index do |entry, i| msg = "#{i == 0 ? "on" : "from"} line #{entry[:line]}" msg << " of #{entry[:filename] || "an unknown file"}" msg << ", in `#{entry[:mixin]}'" if entry[:mixin] trace << msg end trace end