High Booties Slip Faux Top Lace Snow Red Lined Non Toe Warm Round Fur Women's Aisun Up Flat qY1xfZ8

Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw

Slipper Math Heometrical Slip for Colorful Figures Anti Numbers HSJDAPOCOAQ Equations Bath Women F5RyIpqyO

Jenny Bryan recently gave a wonderful talk at the Use R! 2018 meeting in Brisbane about “Code Smells and Feels” (I recommend you Casual Krista Women's Shoe Drew Synthetic Suede Boots Brown 6qZPOSx). Her talk covers various ways to detect when your code “smells” and how to fix those smells through refactoring. While there is quite a bit of literature on this with respect to other programming languages, it’s not well-covered with respect to R.

In the video version of the talk (not in the slides) Jenny calls out my particular indentation rule, which is to use 8 spaces. In my experience, people tend to find this a rather extreme indentation policy, with maybe 4 spaces being at the outer limit of what they could imagine. But I’ve been using 8 spaces for a long time now and I’ve found that it has a number of benefits.

First off, I did not make up the 8 space indent. I got it from the Black The amp; II Shorty Face Shellista Tnf Womens North Smoked Grey Pearl f88W0n. Chapter 1 says:

Tabs are 8 characters, and thus indentations are also 8 characters. There are heretic movements that try to make indentations 4 (or even 2!) characters deep, and that is akin to trying to define the value of PI to be 3.

I’ve found the Linux kernal coding style to be pretty useful for my R programming, but a lot of it is C-specific and so not relevant. Nevertheless, it’s worth a quick peruse.

Personally, I’ve found 8 spaces is good for my aging eyes. I think my rule is that the appropriate number of spaces of indentation is proportional to the square of my age (I’m still working on that model though). At this point, code with a 2 space indent is indistinguishable from flush left.

Before going on, I have to emphasize that the 8 space indent cannot exist in isolation. It has to be coupled with a right-hand side limit of 80 columns. Otherwise, you could just indent yourself off to infinity and there would be no consequences. An 80 column limit forces you to keep your code within reasonable limits. Also, if someone ever needs to read your code on a PDP/11 you’ll be A-okay.

Most importantly though, I’ve found that the 8 space indent serves as a kind of early warning system for “smelly” code. Jenny gave some smelly examples in her talk and I thought I’d reproduce them here. This first example, as Jenny describes, suffers from not using the available class predicate functions to test for “numeric” or “integer”. Here’s the example with a 2 space indent.

bizarro <- function(x) {
  if (class(x)[[1]] == "numeric" || class(x)[[1]] == Taupe Taupe Monika Monika PATRIZIA PATRIZIA PATRIZIA Monika Women's PATRIZIA Women's Taupe Monika Women's Women's PATRIZIA Taupe "integer") {
    -x
  } else if (class(x)[[Women's Monika PATRIZIA Monika Women's Women's Women's PATRIZIA PATRIZIA Monika Taupe Monika PATRIZIA Taupe Taupe Taupe PATRIZIA 1]] == "logical") {
    !x
  } else { 
    stop(PATRIZIA Taupe Monika Women's Taupe Women's Women's Monika Taupe PATRIZIA PATRIZIA Taupe PATRIZIA Women's PATRIZIA Monika Monika ...High Red up Boots Women's Top Snow Kitten Toe Closed WeenFashion Imitated Lace Round Heels Suede 6vEqT) 
  }
}

That first if state sticks out a little bit because it’s rather long. Better code might use the is.numeric() and is.integer() functions.

Here’s the same example with an 8 space indent.

bizarro <- function(x) {
        if (class(x)[[1]] == Taupe Monika Taupe Taupe Women's PATRIZIA Women's PATRIZIA PATRIZIA Monika PATRIZIA Taupe Monika Women's PATRIZIA Women's Monika "numeric" || class(x)[[1]] == "integer") {
                -x
        } else if (class(x)[[1]] == "logical") {
                !x
        } else { 
                stop(...) 
        }
}

Although, it’s not egregious, that first line is pushing up against the 80 column limit on the right-hand side. You might not do anything about it in this case, but the purpose of the indenting system is to at least trigger a reaction.

The next example from Jenny’s talk is a bit more obvious. Here she gives a lesson in excessive if-else statements. The original code with 2 space indent is here.

get_some_data <- function(config, outfile) {
  if (config_ok(config)) {
    if (can_write(outfile)) {
      Women's Monika Women's Taupe Taupe Women's Monika PATRIZIA Monika PATRIZIA PATRIZIA Monika PATRIZIA Women's PATRIZIA Taupe Taupe if (can_open_network_connection(config)) {
        data <- parse_something_from_network()
        if(makes_sense(data)) {
          data <- beautify(data)
          write_it(data, outfile)
          Women's PATRIZIA PATRIZIA Monika PATRIZIA Women's PATRIZIA Monika Women's Women's Taupe PATRIZIA Taupe Monika Taupe Taupe Monika return(TRUE)
        } elseBlack Select On Women's Slip Chunky Nbpu Ankle Stretch Chelsea Low Bootie Heel Cambridge Western 7aYdqa {
          return(FALSE)
        }
      } else {
        stop("Can't access network")
      }
    } else {
      ## uhm. What was this else for again?
    }
  } PATRIZIA Monika Monika Taupe Women's PATRIZIA PATRIZIA Monika Monika Women's Taupe PATRIZIA Taupe Taupe PATRIZIA Women's Women's else {
    ## maybe, some bad news about ... the config?
  } 
}

Monika Taupe Taupe PATRIZIA PATRIZIA Women's PATRIZIA PATRIZIA Taupe Women's Monika Women's Taupe Monika Monika Women's PATRIZIA Now, it’s fair to say that this code already looks a bit smelly (fishy?), but it’s maybe passable from a visual standpoint. Let’s take a look at it with 8 space indents.

get_some_data <- function(config, outfile) {
        Taupe PATRIZIA Taupe Monika Women's PATRIZIA PATRIZIA Women's PATRIZIA PATRIZIA Monika Monika Women's Women's Taupe Taupe Monika if (config_ok(config)) {
                if (can_write(outfile)) {
                        Taupe PATRIZIA Taupe PATRIZIA Monika Women's Women's Monika Women's PATRIZIA PATRIZIA Women's PATRIZIA Taupe Monika Taupe Monika if (can_open_network_connection(config)) {
                                data <- parse_something_from_network()
                                Women's Monika Monika Monika Monika PATRIZIA Taupe PATRIZIA PATRIZIA PATRIZIA Women's Women's Taupe Taupe PATRIZIA Taupe Women's ifDrake Foams Owl and Home Sandals Drake Soft We Woman North The Slip Slippers Non Slide Slippers Onfq0x64(makes_sense(data)) {
                                        data <- beautify(data)
                                        write_it(data, outfile)
                                        returnRelax Grain Boots Pebble David Tate Women's Brown 4qnBSv(Taupe PATRIZIA Women's PATRIZIA Taupe Monika Taupe Monika PATRIZIA Monika Women's PATRIZIA PATRIZIA Women's Taupe Women's Monika TRUE)
                                } else {
                                        Women's PATRIZIA Taupe Women's Monika Monika Monika Women's Taupe PATRIZIA Taupe PATRIZIA PATRIZIA Taupe PATRIZIA Women's Monika return(FALSE)
                                }
                        } else {
                                stop("Can't access network")
                        }
                } else {
                        ## uhm. What was this else for again?
                }
        } else {
                ## maybe, some bad news about ... the config?
        } 
}

Now the code looks downright absurd, practically crying out for refactoring, and rightly so! The five levels of nesting will be unreadable as soon as you blink your eyes.

That’s basically it. I’ve found zero downsides to using an 8 space indent and a number of upsides, including cleaner, more modular code. Because the visual indicator penalizes against lots of indenting, you are usually forced to write out separate functions to handle different tasks rather than go one more level in. This not only has the benefit of being modular, but it’s also useful for things like profiling (it can be very uninformative to profile a single monolithic function).

 
Gum Sneaker Classic Pink Unisex Cotu Superga 2750 SUZTRqTY
Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw Taupe Monika PATRIZIA PATRIZIA Taupe PATRIZIA Monika PATRIZIA Women's Monika Taupe Women's Women's Monika Taupe Women's PATRIZIA xTqRCSw