Class: Sass::Environment

Inherits:
Object
  • Object
show all
Defined in:
lib/sass/environment.rb

Overview

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 Script::Functions.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent = nil) ⇒ Environment

Returns a new instance of Environment.

Parameters:



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# 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

Instance Attribute Details

#options ⇒ {Symbol => Object}

The options hash. See the Sass options documentation.

Returns:

  • ({Symbol => Object}) 


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# File 'lib/sass/environment.rb', line 37

def options
  @options || parent_options || {}
end

#parent ⇒ Environment (readonly)

The enclosing environment, or nil if this is the global environment.

Returns:



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# File 'lib/sass/environment.rb', line 20

def parent
  @parent
end

Instance Method Details

#files_in_use ⇒ Set<String>

A set of names of files currently present in the stack.

Returns:

  • (Set<String>) —

    The filenames.



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# File 'lib/sass/environment.rb', line 99

def files_in_use
  @files_in_use ||= @parent.files_in_use
end

#mixins_in_use ⇒ Set<String>

A set of names of mixins currently present in the stack.

Returns:

  • (Set<String>) —

    The mixin names.



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# File 'lib/sass/environment.rb', line 92

def mixins_in_use
  @mixins_in_use ||= @parent.mixins_in_use
end

#pop_frame

Pop a stack frame from the mixin/include stack.



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# File 'lib/sass/environment.rb', line 75

def pop_frame
  pop_and_unuse if stack.last && stack.last[:prepared]
  pop_and_unuse
end

#prepare_frame(frame_info)

Like #push_frame, but next time a stack frame is pushed, it will be merged with this frame.

Parameters:

  • frame_info ({Symbol => Object}) —

    Same as for #push_frame.



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# File 'lib/sass/environment.rb', line 70

def prepare_frame(frame_info)
  push_frame(frame_info.merge(:prepared => true))
end

#push_frame(frame_info)

Push a new stack frame onto the mixin/include stack.

Parameters:

  • 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.



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# 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

#stack ⇒ Array<{Symbol => Object}>

A list of stack frames in the mixin/include stack. The last element in the list is the most deeply-nested frame.

Returns:

  • (Array<{Symbol => Object}>) —

    The stack frames, of the form passed to #push_frame.



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# File 'lib/sass/environment.rb', line 85

def stack
  @stack ||= @parent.stack
end

#stack_trace 



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# 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