Class: Itonoko::CSS::Tokenizer

Inherits:
Object
  • Object
show all
Defined in:
lib/itonoko/css/tokenizer.rb

Overview

Produces a flat array of tokens from a CSS selector string.

Defined Under Namespace

Classes: Token

Constant Summary collapse

IDENT_RE = 
/[a-zA-Z_\-][a-zA-Z0-9_\-]*/
IDENT_STAR_RE = 
/[a-zA-Z_\-*][a-zA-Z0-9_\-]*/

Instance Method Summary collapse

Instance Method Details

#tokenize(str) ⇒ Object 



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# File 'lib/itonoko/css/tokenizer.rb', line 14

def tokenize(str)
  scanner = StringScanner.new(str.to_s.strip)
  tokens  = []

  until scanner.eos?
    if scanner.scan(/\s*,\s*/)
      tokens << Token.new(:comma, ",")

    elsif scanner.scan(/\s*>\s*/)
      tokens << Token.new(:combinator, ">")

    elsif scanner.scan(/\s*\+\s*/)
      tokens << Token.new(:combinator, "+")

    elsif scanner.scan(/\s*~\s*/)
      tokens << Token.new(:combinator, "~")

    elsif scanner.scan(/\s+/)
      # Descendant combinator (whitespace) — only emit if meaningful
      tokens << Token.new(:combinator, " ") unless tokens.empty? || tokens.last.type == :comma

    elsif scanner.scan(/\*/)
      tokens << Token.new(:universal, "*")

    elsif scanner.scan(/#(#{IDENT_RE})/o)
      tokens << Token.new(:id, scanner[1])

    elsif scanner.scan(/\.(#{IDENT_RE})/o)
      tokens << Token.new(:class, scanner[1])

    elsif scanner.scan(/:not\(/i)
      inner = scan_balanced_paren(scanner)
      tokens << Token.new(:pseudo, "not(#{inner})")

    elsif scanner.scan(/::?(#{IDENT_RE}(?:\([^)]*\))?)/o)
      tokens << Token.new(:pseudo, scanner[1])

    elsif scanner.scan(/\[/)
      attr_token = scan_attribute(scanner)
      tokens << attr_token

    elsif scanner.scan(/(#{IDENT_STAR_RE})/o)
      tokens << Token.new(:tag, scanner[1])

    else
      scanner.getch  # skip unknown char
    end
  end

  tokens
end