Module: IRB::NestingParser

Defined in:
lib/irb/nesting_parser.rb

Defined Under Namespace

Classes: NestingElem, NestingVisitor

Class Method Summary collapse

Class Method Details

.open_nestings(parse_lex_result) ⇒ Object

Return a list of open nesting elements at EOF position



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# File 'lib/irb/nesting_parser.rb', line 345

def open_nestings(parse_lex_result)
  parse_by_line(parse_lex_result).last[1]
end

.parse_by_line(parse_lex_result) ⇒ Object

Calculates nesting information [prev_opens, next_opens, min_depth] for each line. Example code

["hello
world"+(

First line

prev_opens: []
next_opens: [lbracket, tstring_beg]
min_depth:  0 (minimum at beginning of line)

Second line

prev_opens: [lbracket, tstring_beg]
next_opens: [lbracket, lparen]
min_depth:  1 (minimum just after tstring_end)



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# File 'lib/irb/nesting_parser.rb', line 362

def parse_by_line(parse_lex_result)
  visitor = NestingVisitor.new
  node, tokens = parse_lex_result.value
  node.accept(visitor)
  tokens.each do |token,|
    case token.type
    when :EMBDOC_BEGIN
      visitor.open_location(token.location, :on_embdoc_beg, '=begin')
    when :EMBDOC_END
      visitor.close_location_start(token.location)
    end
  end
  nestings = visitor.nestings
  last_nesting = nestings.last || []

  num_lines = parse_lex_result.source.source.lines.size
  num_lines.times.map do |i|
    prev_opens = i == 0 ? [] : nestings[i - 1] || last_nesting
    opens = nestings[i] || last_nesting
    min_depth = prev_opens.zip(opens).take_while { |s, e| s == e }.size
    [prev_opens, opens, min_depth]
  end
end