[ACCEPTED]-Use of special characters in function names-method-names

Accepted answer
Score: 19

The answer is, of course, language (and 24 language culture) specific.

For example, depending 23 on the language, all of the following are 22 appropriate: empty-p, empty?, empty, is_empty 21 or isEmpty. (These examples are, of course, not 20 inclusive).

The examples in the original 19 question come from Ruby where such use of 18 ? and ! to end method names are, where appropriate, accepted. This 17 acceptance comes from 1) readily accessible 16 as symbol terminators in the grammar 2) use 15 of ? and ! in the standard library. However, it 14 should be note that ! is not used universally 13 to imply "side-effect" and is 12 generally only present on alternative forms: save/save!, sort/sort!, etc. There 11 are an overwhelming number of methods that 10 perform side-effects which do not have the 9 ! prefix.

Personally, if I was designing 8 a language, I would allow ?, ! and ' to 7 be valid unquoted trailing characters in 6 symbol names. Even though that some languages 5 allow full symbol escaping, such as Scala, such 4 symbols are usually avoided because it's 3 a pain to have to quote them for use.

// in Scala, esp. with Java-compat, the last form is generally used although
// the first two are perfectly valid -- do what makes sense in the language

When 2 in Rome...

  • Scala - empty? or empty_? (not common)
  • C/C++/JS/Java/Python/Perl - no ? or ! in identifiers; JS/Java allow $; $ is a sigil in Perl
  • C/C++/Perl/JS - hands up in the air?
  • C# - IsEmpty (method or property) or Empty (property)
  • Python - is_empty or isEmpty per Guido-guide (although usually len protocol: if not len(foo): "empty!")
  • Java - isEmpty per Language Guide
  • Ruby - special trailing ? and ! (quoting?)
  • JS - indirect identifier access: obj["empty?"] (not common for this)
  • Lisp (conventional): empty-p for predicate; variations in reader/quoting
  • Julia - appends ! to functions that modify their arguments

Glad to see corrections and/or 1 additions -- is only a drop in a bucket.

Score: 3

I'm not a big fan of special characters 11 in function names, but then I'll also beat 10 to death, with a stick of wet celery to 9 tease out the pain, anyone I find putting 8 spaces into file names :-)

The ? variant can 7 just as easily be done with something like 6 isEmpty() and the ! variant with sortInPlace().

English is a very 5 adaptive language, even without the punctuation.

In 4 either case, my languages of choice (C and 3 Java) use punctuation for all sorts of other 2 things. Having them in identifiers as well 1 would make the lexical analysis a nightmare.

Score: 1

Prepending "@" to a method name 4 (or any identifier) in C# allows you to 3 name that method with a normally-reserved 2 keyword.

void null() {}
// Invalid token 'null' in class, struct, or interface member declaration

void @null()
// compiles

Don't do this; it's mainly for machine-generated 1 code, like datasets. MSDN page on the topic.

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