Class: GmailSearchSyntax::Tokenizer

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

Constant Summary collapse

OPERATORS = 
%w[
  from to cc bcc subject after before older newer older_than newer_than
  label category has list filename in is deliveredto size larger smaller
  rfc822msgid
].freeze
LOGICAL_OPERATORS = 
%w[OR AND AROUND].freeze

Instance Method Summary collapse

Constructor Details

#initialize(input) ⇒ Tokenizer

Returns a new instance of Tokenizer.



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# File 'lib/gmail_search_syntax/tokenizer.rb', line 29

def initialize(input)
  @input = input
  @position = 0
  @tokens = []
end

Instance Method Details

#tokenize ⇒ Object 



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# File 'lib/gmail_search_syntax/tokenizer.rb', line 35

def tokenize
  while @position < @input.length
    skip_whitespace

    break if @position >= @input.length

    char = current_char

    case char
    when "("
      add_token(:lparen, char)
      advance
    when ")"
      add_token(:rparen, char)
      advance
    when "{"
      add_token(:lbrace, char)
      advance
    when "}"
      add_token(:rbrace, char)
      advance
    when "-"
      next_char = peek_char
      prev_char = (@position > 0) ? @input[@position - 1] : nil
      # Negation requires: non-whitespace follows AND (start of input OR whitespace precedes)
      # Gmail behavior: "Coxlee-Gammage" → Coxlee AND Gammage (hyphen is word separator)
      #                 "Coxlee -Gammage" → Coxlee AND NOT Gammage (space+hyphen = negation)
      if next_char && next_char !~ /\s/ && (prev_char.nil? || prev_char =~ /\s/)
        add_token(:minus, char)
        advance
      elsif prev_char && prev_char !~ /\s/
        # Embedded hyphen (preceded by non-whitespace) - skip it as word separator
        advance
      else
        read_word
      end
    when "+"
      add_token(:plus, char)
      advance
    when '"'
      read_quoted_string
    when ":"
      add_token(:colon, char)
      advance
    else
      read_word
    end
  end

  add_token(:eof, nil)
  @tokens
end