Programming languages vary a lot, but some things are always difficult, one of these is to name variables and functions.
You probably follow some kind of code convention, like the ones for Ruby, Python, Scala, or Haskell. However, they seldom offer advice about which names to use. Here I offer you some rules I follow and a list of my preferred words (Warning: some are less than… ahem… conventional, but they work really fine).
- Frequent variables and functions should have short names or standard abbreviations, also, try to keep the same number of letters;
- A lot of things happens in pairs, have symmetric names for them;
- Symmetric names should have the same number of letters when possible (believe me, it makes a difference);
- Words frequently used to compose names (like input_file, output_file) should have short names (4 letters) or standard abbreviations (2 or 3 letters).
Below are the suggested names, on the left-hand side are the names that usually come to mind. On the right-hand side are alternatives, I make bold the ones I like most.
input, output => abbrev: inp, out (I prefer source/target)
in, out => enter, leave
from, to => since, until or enter, leave
source, target => abbrev: src, tgt
read, write => load, save
produce, consume or producer, consumer => abbrev: prd, cns
start, finish/stop => rush, stop / depart, cancel, arrive (this has 3 states)
enter, exit => enter, leave
begin, end => begin, cease (it’s odd until you get use to it)
open, close => open, shut
up, down => abbrev: up, dn (side note: “dn” is “up” upside down) ;p
create, destroy => create, update, delete (3 states) / born, wake, rest, slay (those are 4 states, I like them for workers)
send, receive or sender, receiver => abbrev: snd, rec (I prefer “pull, push”, “throw, catch”, or “producer, consumer”)
throw, catch (they are reserved in Java and probably other languages)
black, white, green, amber, rouge, brown, ashes
top, bottom => north, south
left, right => west, east
width, height => wide, tall
Single Names for very short functions/methods
Those are useful for really short functions and methods, like 1 to 3 lines, or sometimes as argument names when the method is short AND generic (the classic “helper methods”.)
result => abbrev: rslt (I prefer it over “accumulator” or “acc” or any kind of “I’m building something and I’ll return it”)
channel => abbrev: chnl
file_name / filename => path (I really don’t like “filename” together, not sure why)
socket => sckt
string => text
x, y, z (for numbers in one-liners)
array / vector / list /sequence => abbrev: lst or seq (never, ever just “l”, it’s too similar to “1”), I usually don’t abbreviate it, the word is already short.
hashtable/ dictionary => abbrev: dict or hsh (“dict” makes a nice pair with “list”)
iterator => abbrev: iter
enumerator => abbrev: enum
Note: I usually use plural words for collections instead of “list”, “dict”. But sometimes you have a “list of I-don’t-care” and then these names makes sense.
Loops and Iterators
i, j, k for indexes.
n when looping over numbers, not indexes.
e when looping over elements.
a, b, c when we have nested loops over elements.
k, v when iterating over keys and values of a Hashtable/Dictionary/Map.
k, v, t, u when iterating over a Dictionary of Dictionaries, but I still don’t like it.
count, total when counting and summing.
Note: if the loop has more than 2 lines, I usually avoid those short names, but they really shine in one-liners iterators / list comprehensions.
My intention is to create a Github page later and expand it. But I thought that’s better to start somewhere (even incomplete) than waiting until I “get it ready”.