class Byebug::ListCommand

Implements byebug “list” command.

def description 

def description
  %{l[ist]\t\tlist forward
    l[ist] -\tlist backward
    l[ist] =\tlist current line
    l[ist] nn-mm\tlist given lines
    * NOTE - to turn on autolist, use 'set autolist'}
end

def display_list(b, e, lines, current)


otherwise we return the previous line @state.previous_line.
current line number. If we can show from B to E then we return B,
Show file lines in LINES from line B to line E where CURRENT is the
# 
def display_list(b, e, lines, current)
  width = e.to_s.size
  b.upto(e) do |n|
    if n > 0 && lines[n-1]
      if n == current
        print "=> %#{width}d: %s\n", n, lines[n-1].chomp
      else
        print "   %#{width}d: %s\n", n, lines[n-1].chomp
      end
    end
  end
  print "\n"
  return e == lines.size ? @state.previous_line : b
end

def execute 

def execute
  Byebug.source_reload if Command.settings[:autoreload]
  lines = LineCache::getlines @state.file, Command.settings[:autoreload]
  if !lines
    errmsg "No sourcefile available for #{@state.file}\n"
    return @state.previous_line
  end
  b, e = set_line_range(Command.settings[:listsize], lines.size)
  return @state.previous_line if b < 0
  print "\n[#{b}, #{e}] in #{@state.file}\n"
  @state.previous_line = display_list(b, e, lines, @state.line)
end

def names 

def names
  %w(list)
end

def regexp 

def regexp
  /^\s* l(?:ist)? (?:\s*([-=])|\s+(\S+))? \s*$/x
end

def set_line_range(listsize, maxline)

Parameters:
  • maxline () -- - max line number that can be printed
  • listsize () -- - number of lines to be printed 
def set_line_range(listsize, maxline)
  if !@match || !(@match[1] || @match[2])
    b = @state.previous_line ?
    @state.previous_line + listsize : @state.line - (listsize/2)
  elsif @match[1] == '-'
    b = if @state.previous_line
          if  @state.previous_line > 0
            @state.previous_line - listsize
          else
            @state.previous_line
          end
        else
          @state.line - (listsize/2)
        end
  elsif @match[1] == '='
    @state.previous_line = nil
    b = @state.line - (listsize/2)
  else
    b, e = @match[2].split(/[-,]/)
    if e
      b = b.to_i
      e = e.to_i
    else
      b = b.to_i - (listsize/2)
    end
  end
  if b > maxline
    errmsg "Invalid line range"
    return [ -1, -1 ]
  end
  b = [1, b].max
  e ||=  b + listsize - 1
  if e > maxline
    e = maxline
    b = e - listsize + 1
    b = [1, b].max
  end
  return [ b, e ]
end