Class: Jsonerino::Lexer

Inherits:
Object
  • Object
show all
Defined in:
lib/jsonerino/lexer.rb

Constant Summary collapse

SIMPLE_TOKENS_MATCHER = 
[
  ['{', Token::TOKEN_LCURLY],
  ['}', Token::TOKEN_RCURLY],
  ['[', Token::TOKEN_LBRACKET],
  [']', Token::TOKEN_RBRACKET],
  [':', Token::TOKEN_COLON],
  [',', Token::TOKEN_COMMA]
].freeze
SIMPLE_ESCAPE_SEQUENCES_MATCHER = 
['"', '"'],
  ['b', "\b"],
  ['f', "\f"],
  ['r', "\r"],
  %W[n \n],
  %W[t \t]
].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(contents) ⇒ Lexer

Returns a new instance of Lexer.



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# File 'lib/jsonerino/lexer.rb', line 26

def initialize(contents)
  @contents = contents
  @i = 0
  @l = 1 # Line number (row)
  @li = 1 # Character in current line (column)
  @c = contents[@i]
end

Instance Attribute Details

#i ⇒ Object (readonly)

Returns the value of attribute i.



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# File 'lib/jsonerino/lexer.rb', line 24

def i
  @i
end

Instance Method Details

#next_token ⇒ Object 



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# File 'lib/jsonerino/lexer.rb', line 34

def next_token
  skip_whitespace

  while more_content?

    v = collect_simple_token
    return v if v

    # Numbers in JSON are only allowed to start with a minus sign
    return collect_number if number?

    return collect_string if @c == '"'

    return collect_id if Helpers.alphanumeric?(@c)

    raise "Unexpected character '#{@c}'"
  end
  nil
end