Class: Cataract::Backends::PureImpl Private

Inherits:
Object
  • Object
show all
Defined in:
lib/cataract/pure.rb,
lib/cataract/pure/parser.rb,
lib/cataract/pure/flatten.rb,
lib/cataract/pure/serializer.rb,
lib/cataract/pure/specificity.rb,
lib/cataract/pure/declarations.rb,
lib/cataract/pure/byte_constants.rb

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

Defined Under Namespace

Classes: FlattenImpl, Parser, Serializer

Constant Summary collapse

PURE_RUBY_LOADED =

Flag to indicate the pure Ruby backend is loaded

true
IMPLEMENTATION =

Implementation type constant

:ruby
COMPILE_FLAGS =

Compile flags (mimic C version)

{
  debug: false,
  str_buf_optimization: false,
  pure_ruby: true
}.freeze
Flatten =

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

A frozen singleton, same rationale as Pure itself (see pure.rb) - none of FlattenImpl's methods touch instance state, so one shared instance is as safe as the bare module this replaces.

FlattenImpl.new.freeze
PSEUDO_ELEMENT_KEYWORDS =

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

Legacy CSS2 pseudo-elements written with a single colon (e.g. :before) that must still be counted as pseudo-elements, not pseudo-classes.

%w[before after first-line first-letter selection].freeze
BYTE_SPACE =

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

Whitespace bytes

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BYTE_TAB =

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

' '

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BYTE_NEWLINE =

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

'\t'

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BYTE_CR =

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

'\n'

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BYTE_AT =

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

CSS structural characters

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BYTE_LBRACE =

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

'@'

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BYTE_RBRACE =

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

'{'

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BYTE_LPAREN =

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

'}'

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BYTE_RPAREN =

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

'('

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BYTE_LBRACKET =

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

')'

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BYTE_RBRACKET =

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

'['

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BYTE_SEMICOLON =

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

']'

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BYTE_COLON =

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

';'

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BYTE_COMMA =

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

':'

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BYTE_SLASH =

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

Comment characters

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BYTE_STAR =

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

'/'

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BYTE_SQUOTE =

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

Quote characters

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BYTE_DQUOTE =

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

"'"

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BYTE_HASH =

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

Selector characters

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BYTE_DOT =

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

'#'

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BYTE_GT =

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

'.'

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BYTE_PLUS =

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

'>'

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BYTE_TILDE =

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

'+'

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BYTE_ASTERISK =

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

'~'

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BYTE_AMPERSAND =

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

'*'

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BYTE_HYPHEN =

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

Other

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BYTE_UNDERSCORE =

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

'-'

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BYTE_BACKSLASH =

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

'_'

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BYTE_BANG =

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

'\'

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BYTE_PERCENT =

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

'!'

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BYTE_EQUALS =

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

'%'

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BYTE_CARET =

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

'='

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BYTE_DOLLAR =

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

'^'

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BYTE_PIPE =

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

'$'

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BYTE_LOWER_U =

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

Specific lowercase letters (for keyword matching)

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BYTE_LOWER_R =

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

'u'

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BYTE_LOWER_L =

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

'r'

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BYTE_LOWER_D =

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

'l'

100
BYTE_LOWER_T =

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

'd'

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BYTE_LOWER_N =

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

't'

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BYTE_UPPER_U =

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

Specific uppercase letters (for case-insensitive matching)

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BYTE_UPPER_R =

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

'U'

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BYTE_UPPER_L =

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

'R'

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BYTE_UPPER_D =

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

'L'

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BYTE_UPPER_T =

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

'D'

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BYTE_UPPER_N =

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

'T'

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BYTE_LOWER_A =

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

Letter ranges (a-z, A-Z)

97
BYTE_LOWER_Z =

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

'a'

122
BYTE_UPPER_A =

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

'z'

65
BYTE_UPPER_Z =

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

'A'

90
BYTE_CASE_DIFF =

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

'Z'

32
BYTE_DIGIT_0 =

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

Digit range (0-9)

48
BYTE_DIGIT_9 =

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

'0'

57
NESTING_STYLE_IMPLICIT =

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

Nesting styles (for CSS nesting support)

0
NESTING_STYLE_EXPLICIT =

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

Implicit nesting: .parent { .child { ... } } => .parent .child

1

Instance Method Summary collapse

Instance Method Details

#calculate_specificity(selector) ⇒ Integer

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.

Calculate CSS specificity for a selector

Specificity calculation (per CSS spec):

  • Count IDs (#id) - each worth 100
  • Count classes/attributes/pseudo-classes (.class, [attr], :pseudo) - each worth 10
  • Count elements/pseudo-elements (div, ::before) - each worth 1

Parameters:

  • selector (String) —

    CSS selector

Returns:

  • (Integer) —

    Specificity value



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# File 'lib/cataract/pure/specificity.rb', line 39

def calculate_specificity(selector)
  return 0 if selector.nil? || selector.empty?

  # Counters for specificity components
  id_count = 0
  class_count = 0
  attr_count = 0
  pseudo_class_count = 0
  pseudo_element_count = 0
  element_count = 0

  i = 0
  len = selector.length

  while i < len
    byte = selector.getbyte(i)

    if byte == BYTE_HASH
      id_count += 1
      i = skip_identifier(selector, i + 1, len)
    elsif byte == BYTE_DOT
      class_count += 1
      i = skip_identifier(selector, i + 1, len)
    elsif byte == BYTE_LBRACKET
      attr_count += 1
      i = skip_attribute_selector(selector, i, len)
    elsif byte == BYTE_COLON
      i, is_not, not_content, counts_as_element = parse_pseudo(selector, i, len)
      if not_content
        # :not() doesn't count itself, but its content does
        not_specificity = calculate_specificity(not_content)
        id_count += not_specificity / 100
        class_count += (not_specificity % 100) / 10
        element_count += not_specificity % 10
      elsif !is_not
        if counts_as_element
          pseudo_element_count += 1
        else
          pseudo_class_count += 1
        end
      end
    elsif letter?(byte)
      element_count += 1
      i = skip_identifier(selector, i + 1, len)
    else
      # Whitespace, combinators, and the universal selector (*) all have
      # zero specificity - just skip a single byte.
      i += 1
    end
  end

  # Calculate specificity using W3C formula
  (id_count * 100) +
    ((class_count + attr_count + pseudo_class_count) * 10) +
    ((element_count + pseudo_element_count) * 1)
end

#expand_shorthand(decl) ⇒ Array<Declaration>

Expand a single shorthand declaration into longhand declarations. Called by Rule#expanded_declarations - not meant for direct use.

Parameters:

Returns:

  • (Array<Declaration>) —

    Array of expanded longhand declarations



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# File 'lib/cataract/pure.rb', line 100

def expand_shorthand(decl)
  Flatten.expand_shorthand(decl)
end

#flatten(stylesheet) ⇒ Stylesheet

Flatten stylesheet rules according to CSS cascade rules

Parameters:

  • stylesheet (Stylesheet) —

    Stylesheet to flatten

Returns:

  • (Stylesheet) —

    New stylesheet with flattened rules



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# File 'lib/cataract/pure.rb', line 91

def flatten(stylesheet)
  Flatten.flatten(stylesheet, mutate: false)
end

#parse(css_string, parser_options = {}) ⇒ Hash

Parse CSS string and return hash with rules, media_index, charset, etc. Called by Stylesheet#add_block - not meant for direct use.

}

Parameters:

  • css_string (String) —

    CSS to parse

  • parser_options (Hash) (defaults to: {}) —

    Parser configuration options

Options Hash (parser_options):

  • :selector_lists (Boolean) — default: true —

    Track selector lists

Returns:

  • (Hash) —

    { rules: Array, # Flat array of Rule/AtRule structs _media_index: Hash, # Symbol => Array of rule IDs charset: String|nil, # @charset value if present _has_nesting: Boolean # Whether any nested rules exist



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# File 'lib/cataract/pure.rb', line 82

def parse(css_string, parser_options = {})
  parser = Parser.new(css_string, parser_options: parser_options)
  parser.parse
end

#parse_declarations(str) ⇒ Array<Declaration>

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.

Parse a standalone CSS declaration-list string ("color: red; margin: 10px") into an array of Declaration structs.

Parameters:

  • str (String) —

    CSS declarations, optionally wrapped in { ... }

Returns:



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# File 'lib/cataract/pure/declarations.rb', line 24

def parse_declarations(str)
  fin = str.bytesize
  pos = 0

  # Strip outer braces and whitespace (css_parser compatibility)
  pos += 1 while pos < fin && (decl_whitespace?(str.getbyte(pos)) || str.getbyte(pos) == BYTE_LBRACE)
  fin -= 1 while fin > pos && (decl_whitespace?(str.getbyte(fin - 1)) || str.getbyte(fin - 1) == BYTE_RBRACE)

  declarations = []

  while pos < fin
    pos += 1 while pos < fin && (decl_whitespace?(str.getbyte(pos)) || str.getbyte(pos) == BYTE_SEMICOLON)
    break if pos >= fin

    span = scan_one_declaration(str, pos, fin)
    break unless span # No colon found - stop parsing entirely

    pos = span[:next_pos]
    next unless span[:val_end] > span[:val_start] # Skip if value is empty

    property = str.byteslice(span[:prop_start], span[:prop_end] - span[:prop_start])
                  .force_encoding(Encoding::US_ASCII).downcase
    value = str.byteslice(span[:val_start], span[:val_end] - span[:val_start]).force_encoding(Encoding::UTF_8)

    declarations << Declaration.new(property, value, span[:important])
  end

  declarations
end

#stylesheet_to_formatted_s(rules, charset, has_nesting, selector_lists = {}, media_queries = [], media_query_lists = {}) ⇒ String

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.

Serialize stylesheet to formatted CSS string (with indentation).

Parameters:

  • rules (Array<Rule>) —

    Array of rules

  • charset (String, nil) —

    @charset value

  • has_nesting (Boolean) —

    Whether any nested rules exist

  • selector_lists (Hash) (defaults to: {}) —

    Selector list ID => array of rule IDs (for grouping)

  • media_queries (Array<MediaQuery>) (defaults to: []) —

    Array of MediaQuery objects

  • media_query_lists (Hash) (defaults to: {}) —

    List ID => array of MediaQuery IDs (for comma-separated queries)

Returns:

  • (String) —

    Formatted CSS string



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# File 'lib/cataract/pure/serializer.rb', line 654

def stylesheet_to_formatted_s(rules, charset, has_nesting, selector_lists = {}, media_queries = [],
                              media_query_lists = {})
  Serializer.new(rules, charset, has_nesting, selector_lists, media_queries, media_query_lists,
                 formatted: true).to_s
end

#stylesheet_to_s(rules, charset, has_nesting, selector_lists = {}, media_queries = [], media_query_lists = {}) ⇒ String

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.

Serialize stylesheet to compact CSS string.

Parameters:

  • rules (Array<Rule>) —

    Array of rules

  • charset (String, nil) —

    @charset value

  • has_nesting (Boolean) —

    Whether any nested rules exist

  • selector_lists (Hash) (defaults to: {}) —

    Selector list ID => array of rule IDs (for grouping)

  • media_queries (Array<MediaQuery>) (defaults to: []) —

    Array of MediaQuery objects

  • media_query_lists (Hash) (defaults to: {}) —

    List ID => array of MediaQuery IDs (for comma-separated queries)

Returns:

  • (String) —

    Compact CSS string



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# File 'lib/cataract/pure/serializer.rb', line 641

def stylesheet_to_s(rules, charset, has_nesting, selector_lists = {}, media_queries = [], media_query_lists = {})
  Serializer.new(rules, charset, has_nesting, selector_lists, media_queries, media_query_lists, formatted: false).to_s
end