Class: YARD::Parser::Ruby::Legacy::RubyLex::BufferedReader Private

Do not use. This class is for internal use only.

Relationships & Source Files
Inherits:	Object
Defined in:	lib/yard/parser/ruby/legacy/ruby_lex.rb

Overview

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(<<-A, <<-B) stuff for A stuff for B

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.

Class Method Summary

.new(content) ⇒ BufferedReader constructor Internal use only

Instance Attribute Summary

#line_num readonly Internal use only

Instance Method Summary

#column Internal use only
#divert_read_from(reserve) Internal use only
#get_read Internal use only
#getc Internal use only
#getc_already_read Internal use only
#peek(at) Internal use only
#peek_equal(str) Internal use only
#ungetc(_ch) Internal use only

Instance Attribute Details

#line_num (readonly)

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 344


attr_reader :line_num

Instance Method Details

#column

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 365


def column
  @offset - @last_newline
end

#divert_read_from(reserve)

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 419


def divert_read_from(reserve)
  @content[@offset, 0] = reserve
  @size = @content.size
end

#get_read

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 400


def get_read
  res = @content[@read_back_offset...@offset]
  @read_back_offset = @offset
  res
end

#getc

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 369


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

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 388


def getc_already_read
  getc
end

#peek(at)

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 406


def peek(at)
  pos = @offset + at
  if pos >= @size
    nil
  else
    @content[pos, 1]
  end
end

#peek_equal(str)

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 415


def peek_equal(str)
  @content[@offset, str.length] == str
end

#ungetc(_ch)

[ GitHub ]

# File 'lib/yard/parser/ruby/legacy/ruby_lex.rb', line 392


def ungetc(_ch)
  raise "unget past beginning of file" if @offset <= 0
  @offset -= 1
  if @content[@offset] == ?\n
    @newline_pending = false
  end
end