class YARD::Parser::Ruby::Legacy::RubyLex::BufferedReader

Read an input stream character by character. We allow for unlimited ungetting of characters just read.

We simplify the implementation greatly by reading the entire input into a buffer initially, and then simply traversing it using pointers.

We also have to allow for the here document diversion. This little gem comes about when the lexer encounters a here document. At this point we effectively need to split the input stream into two parts: one to read the body of the here document, the other to read the rest of the input line where the here document was initially encountered. For example, we might have

do_something("  stuff
  for
", "  stuff
  for
")

When the lexer encounters the <<A, it reads until the end of the line, and keeps it around for later. It then reads the body of the here document. Once complete, it needs to read the rest of the original line, but then skip the here document body.

@private

Attributes

line_num[R]

Public Class Methods

new(content) click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 365
def initialize(content)
  if /\t/ =~ content
    tab_width = 2
    content = content.split(/\n/).map do |line|
      1 while line.gsub!(/\t+/) { ' ' * (tab_width*$&.length - $`.length % tab_width)}  && $~ #`
      line
    end .join("\n")
  end
  @content   = content
  @content << "\n" unless @content[-1,1] == "\n"
  @size      = @content.size
  @offset    = 0
  @hwm       = 0
  @line_num  = 1
  @read_back_offset = 0
  @last_newline = 0
  @newline_pending = false
end

Public Instance Methods

column() click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 384
def column
  @offset - @last_newline
end
divert_read_from(reserve) click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 438
def divert_read_from(reserve)
  @content[@offset, 0] = reserve
  @size      = @content.size
end
get_read() click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 419
def get_read
  res = @content[@read_back_offset...@offset]
  @read_back_offset = @offset
  res
end
getc() click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 388
def getc
  return nil if @offset >= @size
  ch = @content[@offset, 1]

  @offset += 1
  @hwm = @offset if @hwm < @offset

  if @newline_pending
    @line_num += 1
    @last_newline = @offset - 1
    @newline_pending = false
  end

  if ch == "\n"
    @newline_pending = true
  end
  ch
end
getc_already_read() click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 407
def getc_already_read
  getc
end
peek(at) click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 425
def peek(at)
  pos = @offset + at
  if pos >= @size
    nil
  else
    @content[pos, 1]
  end
end
peek_equal(str) click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 434
def peek_equal(str)
  @content[@offset, str.length] == str
end
ungetc(ch) click to toggle source
# File lib/yard/parser/ruby/legacy/ruby_lex.rb, line 411
def ungetc(ch)
  raise "unget past beginning of file" if @offset <= 0
  @offset -= 1
  if @content[@offset] == ?\n
    @newline_pending = false
  end
end