Class: Sass::Tree::Visitors::Perform

Inherits:
Base
  • Object
show all
Defined in:
/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb

Overview

A visitor for converting a dynamic Sass tree into a static Sass tree.

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods inherited from Base

node_name

Constructor Details

- (Perform) initialize(env) (protected)

Returns a new instance of Perform



153
154
155
156
157
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 153

def initialize(env)
  @environment = env
  @in_keyframes = false
  @at_root_without_rule = false
end

Class Method Details

+ perform_arguments(callable, args, splat, environment)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 16

def perform_arguments(callable, args, splat, environment)
  desc = "#{callable.type.capitalize} #{callable.name}"
  downcase_desc = "#{callable.type} #{callable.name}"

  # All keywords are contained in splat.keywords for consistency,
  # even if there were no splats passed in.
  old_keywords_accessed = splat.keywords_accessed
  keywords = splat.keywords
  splat.keywords_accessed = old_keywords_accessed

  begin
    unless keywords.empty?
      unknown_args = Sass::Util.array_minus(keywords.keys,
        callable.args.map {|var| var.first.underscored_name})
      if callable.splat && unknown_args.include?(callable.splat.underscored_name)
        raise Sass::SyntaxError.new("Argument $#{callable.splat.name} of #{downcase_desc} " +
                                    "cannot be used as a named argument.")
      elsif unknown_args.any?
        description = unknown_args.length > 1 ? 'the following arguments:' : 'an argument named'
        raise Sass::SyntaxError.new("#{desc} doesn't have #{description} " +
                                    "#{unknown_args.map {|name| "$#{name}"}.join ', '}.")
      end
    end
  rescue Sass::SyntaxError => keyword_exception
  end

  # If there's no splat, raise the keyword exception immediately. The actual
  # raising happens in the ensure clause at the end of this function.
  return if keyword_exception && !callable.splat

  splat_sep = :comma
  if splat
    args += splat.to_a
    splat_sep = splat.separator
  end

  if args.size > callable.args.size && !callable.splat
    extra_args_because_of_splat = splat && args.size - splat.to_a.size <= callable.args.size

    takes = callable.args.size
    passed = args.size
    message = "#{desc} takes #{takes} argument#{'s' unless takes == 1} " +
      "but #{passed} #{passed == 1 ? 'was' : 'were'} passed."
    raise Sass::SyntaxError.new(message) unless extra_args_because_of_splat
    # TODO: when the deprecation period is over, make this an error.
    Sass::Util.sass_warn("WARNING: #{message}\n" +
      environment.stack.to_s.gsub(/^/m, " " * 8) + "\n" +
      "This will be an error in future versions of Sass.")
  end

  env = Sass::Environment.new(callable.environment)
  callable.args.zip(args[0...callable.args.length]) do |(var, default), value|
    if value && keywords.has_key?(var.name)
      raise Sass::SyntaxError.new("#{desc} was passed argument $#{var.name} " +
                                  "both by position and by name.")
    end

    value ||= keywords.delete(var.name)
    value ||= default && default.perform(env)
    raise Sass::SyntaxError.new("#{desc} is missing argument #{var.inspect}.") unless value
    env.set_local_var(var.name, value)
  end

  if callable.splat
    rest = args[callable.args.length..-1] || []
    arg_list = Sass::Script::Value::ArgList.new(rest, keywords, splat_sep)
    arg_list.options = env.options
    env.set_local_var(callable.splat.name, arg_list)
  end

  yield env
rescue StandardError => e
ensure
  # If there's a keyword exception, we don't want to throw it immediately,
  # because the invalid keywords may be part of a glob argument that should be
  # passed on to another function. So we only raise it if we reach the end of
  # this function *and* the keywords attached to the argument list glob object
  # haven't been accessed.
  #
  # The keyword exception takes precedence over any Sass errors, but not over
  # non-Sass exceptions.
  if keyword_exception &&
      !(arg_list && arg_list.keywords_accessed) &&
      (e.nil? || e.is_a?(Sass::SyntaxError))
    raise keyword_exception
  elsif e
    raise e
  end
end

+ (Sass::Script::Value::ArgList) perform_splat(splat, performed_keywords, kwarg_splat, environment)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 108

def perform_splat(splat, performed_keywords, kwarg_splat, environment)
  args, kwargs, separator = [], nil, :comma

  if splat
    splat = splat.perform(environment)
    separator = splat.separator || separator
    if splat.is_a?(Sass::Script::Value::ArgList)
      args = splat.to_a
      kwargs = splat.keywords
    elsif splat.is_a?(Sass::Script::Value::Map)
      kwargs = arg_hash(splat)
    else
      args = splat.to_a
    end
  end
  kwargs ||= Sass::Util::NormalizedMap.new
  kwargs.update(performed_keywords)

  if kwarg_splat
    kwarg_splat = kwarg_splat.perform(environment)
    unless kwarg_splat.is_a?(Sass::Script::Value::Map)
      raise Sass::SyntaxError.new("Variable keyword arguments must be a map " +
                                  "(was #{kwarg_splat.inspect}).")
    end
    kwargs.update(arg_hash(kwarg_splat))
  end

  Sass::Script::Value::ArgList.new(args, kwargs, separator)
end

+ (Tree::Node) visit(root, environment = nil)

Returns The resulting tree of static nodes.

Parameters:

  • root (Tree::Node)

    The root node of the tree to visit.

  • environment (Sass::Environment) (defaults to: nil)

    The lexical environment.

Returns:

  • (Tree::Node)

    The resulting tree of static nodes.



9
10
11
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 9

def visit(root, environment = nil)
  new(environment).send(:visit, root)
end

Instance Method Details

- visit(node) (protected)

If an exception is raised, this adds proper metadata to the backtrace.



160
161
162
163
164
165
166
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 160

def visit(node)
  return super(node.dup) unless @environment
  @environment.stack.with_base(node.filename, node.line) {super(node.dup)}
rescue Sass::SyntaxError => e
  e.modify_backtrace(:filename => node.filename, :line => node.line)
  raise e
end

- visit_atroot(node) (protected)

Sets a variable that indicates that the first level of rule nodes shouldn't include the parent selector by default.



454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 454

def visit_atroot(node)
  if node.query
    parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
      node.filename, node.options[:importer], node.line)
    node.resolved_type, node.resolved_value = parser.parse_static_at_root_query
  else
    node.resolved_type, node.resolved_value = :without, ['rule']
  end

  old_at_root_without_rule = @at_root_without_rule
  old_in_keyframes = @in_keyframes
  @at_root_without_rule = true if node.exclude?('rule')
  @in_keyframes = false if node.exclude?('keyframes')
  yield
ensure
  @in_keyframes = old_in_keyframes
  @at_root_without_rule = old_at_root_without_rule
end

- visit_children(parent) (protected)

Keeps track of the current environment.



169
170
171
172
173
174
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 169

def visit_children(parent)
  with_environment Sass::Environment.new(@environment, parent.options) do
    parent.children = super.flatten
    parent
  end
end

- visit_comment(node) (protected)

Removes this node from the tree if it's a silent comment.



197
198
199
200
201
202
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 197

def visit_comment(node)
  return [] if node.invisible?
  node.resolved_value = run_interp_no_strip(node.value)
  node.resolved_value.gsub!(/\\([\\#])/, '\1')
  node
end

- visit_content(node) (protected)



377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 377

def visit_content(node)
  content, content_env = @environment.content
  return [] unless content
  @environment.stack.with_mixin(node.filename, node.line, '@content') do
    trace_node = Sass::Tree::TraceNode.from_node('@content', node)
    content_env = Sass::Environment.new(content_env)
    content_env.caller = Sass::Environment.new(@environment)
    with_environment(content_env) do
      trace_node.children = content.map {|c| visit(c.dup)}.flatten
    end
    trace_node
  end
rescue Sass::SyntaxError => e
  e.modify_backtrace(:mixin => '@content', :line => node.line)
  e.add_backtrace(:line => node.line)
  raise e
end

- visit_cssimport(node) (protected)



537
538
539
540
541
542
543
544
545
546
547
548
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 537

def visit_cssimport(node)
  node.resolved_uri = run_interp([node.uri])
  if node.query && !node.query.empty?
    parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
      node.filename, node.options[:importer], node.line)
    node.resolved_query ||= parser.parse_media_query_list
  end
  if node.supports_condition
    node.supports_condition.perform(@environment)
  end
  yield
end

- visit_debug(node) (protected)

Prints the expression to STDERR.



205
206
207
208
209
210
211
212
213
214
215
216
217
218
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 205

def visit_debug(node)
  res = node.expr.perform(@environment)
  if res.is_a?(Sass::Script::Value::String)
    res = res.value
  else
    res = res.to_sass
  end
  if node.filename
    Sass::Util.sass_warn "#{node.filename}:#{node.line} DEBUG: #{res}"
  else
    Sass::Util.sass_warn "Line #{node.line} DEBUG: #{res}"
  end
  []
end

- visit_directive(node) (protected)



513
514
515
516
517
518
519
520
521
522
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 513

def visit_directive(node)
  node.resolved_value = run_interp(node.value)
  old_in_keyframes, @in_keyframes = @in_keyframes, node.normalized_name == "@keyframes"
  with_environment Sass::Environment.new(@environment) do
    node.children = node.children.map {|c| visit(c)}.flatten
    node
  end
ensure
  @in_keyframes = old_in_keyframes
end

- visit_each(node) (protected)

Runs the child nodes once for each value in the list.



232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 232

def visit_each(node)
  list = node.list.perform(@environment)

  with_environment Sass::SemiGlobalEnvironment.new(@environment) do
    list.to_a.map do |value|
      if node.vars.length == 1
        @environment.set_local_var(node.vars.first, value)
      else
        node.vars.zip(value.to_a) do |(var, sub_value)|
          @environment.set_local_var(var, sub_value || Sass::Script::Value::Null.new)
        end
      end
      node.children.map {|c| visit(c)}
    end.flatten
  end
end

- visit_error(node) (protected)

Throws the expression as an error.

Raises:



221
222
223
224
225
226
227
228
229
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 221

def visit_error(node)
  res = node.expr.perform(@environment)
  if res.is_a?(Sass::Script::Value::String)
    res = res.value
  else
    res = res.to_sass
  end
  raise Sass::SyntaxError.new(res)
end

- visit_extend(node) (protected)

Runs SassScript interpolation in the selector, and then parses the result into a Selector::CommaSequence.



251
252
253
254
255
256
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 251

def visit_extend(node)
  parser = Sass::SCSS::StaticParser.new(run_interp(node.selector),
    node.filename, node.options[:importer], node.line)
  node.resolved_selector = parser.parse_selector
  node
end

- visit_for(node) (protected)

Runs the child nodes once for each time through the loop, varying the variable each time.



259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 259

def visit_for(node)
  from = node.from.perform(@environment)
  to = node.to.perform(@environment)
  from.assert_int!
  to.assert_int!

  to = to.coerce(from.numerator_units, from.denominator_units)
  direction = from.to_i > to.to_i ? -1 : 1
  range = Range.new(direction * from.to_i, direction * to.to_i, node.exclusive)

  with_environment Sass::SemiGlobalEnvironment.new(@environment) do
    range.map do |i|
      @environment.set_local_var(node.var,
        Sass::Script::Value::Number.new(direction * i,
          from.numerator_units, from.denominator_units))
      node.children.map {|c| visit(c)}
    end.flatten
  end
end

- visit_function(node) (protected)

Loads the function into the environment.



280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 280

def visit_function(node)
  env = Sass::Environment.new(@environment, node.options)

  if node.normalized_name == 'calc' || node.normalized_name == 'element' ||
      node.name == 'expression' || node.name == 'url'
    @@function_name_deprecation.warn(node.filename, node.line, <<WARNING)
Naming a function "#{node.name}" is disallowed and will be an error in future versions of Sass.
This name conflicts with an existing CSS function with special parse rules.
WARNING
  end

  @environment.set_local_function(node.name,
    Sass::Callable.new(node.name, node.args, node.splat, env,
                       node.children, false, "function", :stylesheet))
  []
end

- visit_if(node) (protected)

Runs the child nodes if the conditional expression is true; otherwise, tries the else nodes.



299
300
301
302
303
304
305
306
307
308
309
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 299

def visit_if(node)
  if node.expr.nil? || node.expr.perform(@environment).to_bool
    with_environment Sass::SemiGlobalEnvironment.new(@environment) do
      node.children.map {|c| visit(c)}
    end.flatten
  elsif node.else
    visit(node.else)
  else
    []
  end
end

- visit_import(node) (protected)

Returns a static DirectiveNode if this is importing a CSS file, or parses and includes the imported Sass file.



313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 313

def visit_import(node)
  if (path = node.css_import?)
    resolved_node = Sass::Tree::CssImportNode.resolved("url(#{path})")
    resolved_node.options = node.options
    resolved_node.source_range = node.source_range
    return resolved_node
  end
  file = node.imported_file
  if @environment.stack.frames.any? {|f| f.is_import? && f.filename == file.options[:filename]}
    handle_import_loop!(node)
  end

  begin
    @environment.stack.with_import(node.filename, node.line) do
      root = file.to_tree
      Sass::Tree::Visitors::CheckNesting.visit(root)
      node.children = root.children.map {|c| visit(c)}.flatten
      node
    end
  rescue Sass::SyntaxError => e
    e.modify_backtrace(:filename => node.imported_file.options[:filename])
    e.add_backtrace(:filename => node.filename, :line => node.line)
    raise e
  end
end

- visit_media(node) (protected)



524
525
526
527
528
529
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 524

def visit_media(node)
  parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
    node.filename, node.options[:importer], node.line)
  node.resolved_query ||= parser.parse_media_query_list
  yield
end

- visit_mixin(node) (protected)

Runs a mixin.



349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 349

def visit_mixin(node)
  @environment.stack.with_mixin(node.filename, node.line, node.name) do
    mixin = @environment.mixin(node.name)
    raise Sass::SyntaxError.new("Undefined mixin '#{node.name}'.") unless mixin

    if node.children.any? && !mixin.has_content
      raise Sass::SyntaxError.new(%(Mixin "#{node.name}" does not accept a content block.))
    end

    args = node.args.map {|a| a.perform(@environment)}
    keywords = Sass::Util.map_vals(node.keywords) {|v| v.perform(@environment)}
    splat = self.class.perform_splat(node.splat, keywords, node.kwarg_splat, @environment)

    self.class.perform_arguments(mixin, args, splat, @environment) do |env|
      env.caller = Sass::Environment.new(@environment)
      env.content = [node.children, @environment] if node.has_children

      trace_node = Sass::Tree::TraceNode.from_node(node.name, node)
      with_environment(env) {trace_node.children = mixin.tree.map {|c| visit(c)}.flatten}
      trace_node
    end
  end
rescue Sass::SyntaxError => e
  e.modify_backtrace(:mixin => node.name, :line => node.line)
  e.add_backtrace(:line => node.line)
  raise e
end

- visit_mixindef(node) (protected)

Loads a mixin into the environment.



340
341
342
343
344
345
346
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 340

def visit_mixindef(node)
  env = Sass::Environment.new(@environment, node.options)
  @environment.set_local_mixin(node.name,
    Sass::Callable.new(node.name, node.args, node.splat, env,
                       node.children, node.has_content, "mixin", :stylesheet))
  []
end

- visit_prop(node) (protected)

Runs any SassScript that may be embedded in a property.



396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 396

def visit_prop(node)
  node.resolved_name = run_interp(node.name)

  # If the node's value is just a variable or similar, we may get a useful
  # source range from evaluating it.
  if node.value.length == 1 && node.value.first.is_a?(Sass::Script::Tree::Node)
    result = node.value.first.perform(@environment)
    node.resolved_value = result.to_s
    node.value_source_range = result.source_range if result.source_range
  elsif node.custom_property?
    node.resolved_value = run_interp_no_strip(node.value)
  else
    node.resolved_value = run_interp(node.value)
  end

  yield
end

- visit_return(node) (protected)

Returns the value of the expression.



415
416
417
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 415

def visit_return(node)
  throw :_sass_return, node.expr.perform(@environment)
end

- visit_root(node) (protected)

Sets the options on the environment if this is the top-level root.



189
190
191
192
193
194
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 189

def visit_root(node)
  yield
rescue Sass::SyntaxError => e
  e.sass_template ||= node.template
  raise e
end

- visit_rule(node) (protected)

Runs SassScript interpolation in the selector, and then parses the result into a Selector::CommaSequence.



421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 421

def visit_rule(node)
  old_at_root_without_rule = @at_root_without_rule
  parser = Sass::SCSS::StaticParser.new(run_interp(node.rule),
    node.filename, node.options[:importer], node.line)
  if @in_keyframes
    keyframe_rule_node = Sass::Tree::KeyframeRuleNode.new(parser.parse_keyframes_selector)
    keyframe_rule_node.options = node.options
    keyframe_rule_node.line = node.line
    keyframe_rule_node.filename = node.filename
    keyframe_rule_node.source_range = node.source_range
    keyframe_rule_node.has_children = node.has_children
    with_environment Sass::Environment.new(@environment, node.options) do
      keyframe_rule_node.children = node.children.map {|c| visit(c)}.flatten
    end
    keyframe_rule_node
  else
    @at_root_without_rule = false
    node.parsed_rules ||= parser.parse_selector
    node.resolved_rules = node.parsed_rules.resolve_parent_refs(
      @environment.selector, !old_at_root_without_rule)
    node.stack_trace = @environment.stack.to_s if node.options[:trace_selectors]
    with_environment Sass::Environment.new(@environment, node.options) do
      @environment.selector = node.resolved_rules
      node.children = node.children.map {|c| visit(c)}.flatten
    end
    node
  end
ensure
  @at_root_without_rule = old_at_root_without_rule
end

- visit_supports(node) (protected)



531
532
533
534
535
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 531

def visit_supports(node)
  node.condition = node.condition.deep_copy
  node.condition.perform(@environment)
  yield
end

- visit_variable(node) (protected)

Loads the new variable value into the environment.



474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 474

def visit_variable(node)
  env = @environment
  env = env.global_env if node.global
  if node.guarded
    var = env.var(node.name)
    return [] if var && !var.null?
  end

  val = node.expr.perform(@environment)
  if node.expr.source_range
    val.source_range = node.expr.source_range
  else
    val.source_range = node.source_range
  end
  env.set_var(node.name, val)
  []
end

- visit_warn(node) (protected)

Prints the expression to STDERR with a stylesheet trace.



493
494
495
496
497
498
499
500
501
502
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 493

def visit_warn(node)
  res = node.expr.perform(@environment)
  res = res.value if res.is_a?(Sass::Script::Value::String)
  @environment.stack.with_directive(node.filename, node.line, "@warn") do
    msg = "WARNING: #{res}\n         "
    msg << @environment.stack.to_s.gsub("\n", "\n         ") << "\n"
    Sass::Util.sass_warn msg
  end
  []
end

- visit_while(node) (protected)

Runs the child nodes until the continuation expression becomes false.



505
506
507
508
509
510
511
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 505

def visit_while(node)
  children = []
  with_environment Sass::SemiGlobalEnvironment.new(@environment) do
    children += node.children.map {|c| visit(c)} while node.expr.perform(@environment).to_bool
  end
  children.flatten
end

- (Object) with_environment(env) { ... } (protected)

Runs a block of code with the current environment replaced with the given one.

Parameters:

Yields:

  • A block in which the environment is set to env.

Returns:

  • (Object)

    The return value of the block.



181
182
183
184
185
186
# File '/home/nweiz/code/sass-site/.sass/lib/sass/tree/visitors/perform.rb', line 181

def with_environment(env)
  old_env, @environment = @environment, env
  yield
ensure
  @environment = old_env
end