class Sprockets::SourceLine

def begins_multiline_comment?
  line =~ /^\s*\/\*(.*)/
end

def begins_pdoc_comment?
  line =~ /^\s*\/\*\*(.*)/
end

def comment
  @comment ||= line[/^\s*\/\/(.*)/, 1]
end

def comment!
  @comment = line
end

def comment?
  !!comment
end

def ends_multiline_comment?
  line =~ /^(.*)*\*\/\s*/
end

def ends_pdoc_comment?
  line =~ /^(.*)*\*\*\/\s*/
end

def initialize(source_file, line, number)
  @source_file = source_file
  @line = line
  @number = number
end

def inspect
  "line #@number of #{@source_file.pathname}"
end

def interpolate_constants!(result, constants)
  result.gsub!(/<%=(.*?)%>/) do
    constant = $1.strip
    if value = constants[constant]
      value
    else
      raise UndefinedConstantError, "couldn't find constant `#{constant}' in #{inspect}"
    end
  end
end

def provide
  @provide ||= (comment || "")[/^=\s+provide\s+\"(.*?)\"\s*$/, 1]
end

def provide?
  !!provide
end

def require
  @require ||= (comment || "")[/^=\s+require\s+(\"(.*?)\"|<(.*?)>)\s*$/, 1]
end

def require?
  !!require
end

def strip_trailing_whitespace!(result)
  result.gsub!(/\s+$/, "")
end

def to_s(constants = source_file.environment.constants)
  result = line.chomp
  interpolate_constants!(result, constants)
  strip_trailing_whitespace!(result)
  result + $/
end