What Language Feature Can You Just Not Live Without?

Question

I always miss python's built-in doc strings when working in other languages. I know this may seem odd, but it allows me to cut down significantly on excess comments while still providing a clean description of my code and any interfaces therein.

• What Language Feature Can You Just Not Live Without?

If someone were building a new language and they asked you what one feature they absolutely must include, what would it be?

This is getting kind of long, so I figured I'd do my best to summarize:

Paraphrased to be language agnostic. If you know of a language which uses something mentioned, please at it in the parenthesis to the right of the feature. And if you have a better format for this list, by all means try it out (if it doesn't seem to work, I'll just roll back).

Regular Expressions ~ torial (Perl)

Garbage Collection ~ SaaS Developer (Python, Perl, Ruby, Java, .NET)

Anonymous Functions ~ Vinko Vrsalovic (Lisp, Python)

Arithmetic Operators ~ Jeremy Ross (Python, Perl, Ruby, Java, C#, Visual Basic, C, C++, Pascal, Smalltalk, etc.)

Exception Handling ~ torial (Python, Java, .NET)

Pass By Reference ~ Chris (Python)

Unified String Format WalloWizard (C#)

Generics ~ torial (Python, Java, C#)

Integrated Query Equivalent to LINQ ~ Vyrotek (C#)

Namespacing ~ Garry Shutler ()

Short Circuit Logic ~ Adam Bellaire ()

Answer 1

Anonymous functions

Answer 2

Namespacing

Answer 3

Regular Expressions.

Answer 4

Pass by reference

Answer 5

Generic Containers (.Net)

Answer 6

Generics and Enums (Java 1.5)

Answer 7

Unified string format (unlike C++, like C#)

Answer 8

Delegates in .NET..

Answer 9

A way to apply a function to all/some/any elements on a collection in a single statement

Answer 10

Reflection.

Answer 11

Definitely Generics...

Answer 12

Reflection, serialization, generics,... (C#)

Answer 13

Exception Handling :-D

Answer 14

with .. do (Delphi)

Answer 15

Conditional compiling

#if .. #then .. #else

Answer 16

Attributes/Annotations

Answer 17

Turing completeness... (Well, duh.)

Answer 18

Clean consistent syntax which is easily scanned and reads naturally (like poetry). I've always felt strongly that language code should speak best to people, and tell the story of what it does. Let the compiler/interpreter figure out how to instruct the computer...

Answer 19

Garbage Collection

Answer 20

With keyword in VB.NET

Answer 21

Turing complete... :)

Answer 22

The foreach statement in C#

Answer 23

.Net LINQ !

Answer 24

Ruby's Closures

Answer 25

Single and double hash in macros...

Answer 26

Couldn't live without arithmetic operators.

Answer 27

Any language should support some way of creating abstractions and allow tasks decomposition.

Answer 28

variable declarations :)

Answer 29

list comprehensions

Answer 30

I can't live without if-else

Answer 31

Variable name declarations. When I realized that both Python and Ruby gladly will interpret your fat-fingerings as the introduction of a new variable, I was really, really horrified. It made me thankful once again for Perl's use strict and my $var declarations.

Answer 32

The ability to define DSLs, incorporated directly into the language. As easy to define an operator in the custom DSL language as it is to define a normal function in the "plain" language.

Writing my code as a description of the problem using a vocabulary that fits the problem and lets me focus on the hard parts, instead of writing low-level plumbing and boilerplate code.

Lisp macros.

Answer 33

short-circuit logic. Seriously, try programming VBscript for a while and you'll be begging to be able to do this:

   if (foo.exists && foo.var > 0)

and not have it crash...

Answer 34

*args and **kwargs in Python.

Answer 35

a [plus equals] b

Answer 36

Hashtables, hashmaps or php arrays :D

Answer 37

"first class functions" aka "functions as first class objects"

Answer 38

Symbolic names.

Answer 39

Parametric polymorphism and dependent types.

Answer 40

Subqueries in SQL

Answer 41

comments: single or multiline.

Answer 42

Solid: the iterator ++ -- etc...

Abstract: recursion (once I 'got' it)

Answer 43

User-Friendly Exception Handling ;)

Answer 44

HTTP(s) support

Answer 45

ColdFusion's cfdump

Use the cfdump tag to get the elements, variables, and values of most kinds of ColdFusion objects. Useful for debugging. You can display the contents of simple and complex variables, objects, components, user-defined functions, and other elements.

There's nothing that cfdump can't do :D

Now that I'm messing with .NET, this is by far the most useful feature of ColdFusion that I wish I could replicate (of course, when I do JavaScript I wish for it as well :D ).

Answer 46

command line compiles

Answer 47

the language feature I am missing is "remove all bug". Might have to be implemented as a compiler option though, so that oldtimers can continue to do without that feature.

Serious answer: Templates/Generics

Answer 48

In C#, the Using () {....} blocks have solved more memory leaks than I can count.

Kind of goes with garbage collection, but more specific.

Answer 49

Pointers!

Really, I'm an old C fart. I cannot live without them anymore..

Answer 50

Locking for thread safety

Answer 51

Attributes in .NET. Once you really understand them and learn how to use them properly (that is, not to overuse them), it opens up a whole new world (now I'm exaggerating a bit).

Answer 52

For in statement for object inspection.

Answer 53

Lambdas for sure.

Answer 54

I'm a big fan of functions.

Answer 55

Tables. Those save me a lot of the headache I had with plain arrays.

Answer 56

pointer to methods (C++)
well, maybe I could have lived without it but its neat non the less.

Answer 57

Scoped Guards (for RAII.)

Sorry, C# - other than that, I think you're swell.

Answer 58

Object-orientation! I can't believe nobody seems to have said this!

Answer 59

Multi-dimensional Arrays.

Answer 60

operator overloading

Answer 61

Extension method of C#

Answer 62

Good collection classes.

Answer 63

Got to say reflection. It really empowers you to do great stuff in statically typed languages.

Answer 64

.NET Generics

Answer 65

first class functions and lexical scope!

Answer 66

Operator overloading (Python-style, a la str())

Answer 67

Static type inferencing.

Answer 68

Properties

Answer 69

LINQ to XML. Seriously :)

With the incredible proliferation of XML used across business problem domains, LINQ to XML can generally turn hundreds of lines of terrible, unmaintainable code into a 10-line query.

Answer 70

The lower half of the right brace }

Answer 71

Introspection combined with running interactively to try out things live. (Python, Perl, Ruby and others I'm sure)

Answer 72

Assignment ;-)

Answer 73

Closures.

(First-class functions in general, but those are implied.)

Answer 74

Delimited continuations. When you can express the future of the computation as a series of composable partial evaluation control structures nested within one another like Russian dolls, going back to iteration seems so mundane. ;)

Granted, when your standards are this high, it severely limits your available programming languages.

Answer 75

Argument defaults a la Python and PHP

>>>def foo(bar='baz',qux='42'):
...  print bar + ' ' + qux

>>>foo('hello')
'hello 42'

Answer 76

Dot.Notation as opposed to arrow->notation, (notation prefix), or function(call(everything))

Answer 77

A full list would comprise the API documentation for a small programming language. I'm also seeing things here that would be a poor fit for certain applications, so I'm trying to list things that aren't ubiquitous, but probably should be.

First-class functions, preferably with a good function literal syntax. Ruby is good here. Arc and Clojure are great. (Missing from Java, PHP and only available in a roundabout way in C and C++. I think C# has some form of this with LINQ.)

Namespaces, packages or some similar way to control what names are visible where. (Missing from Emacs Lisp and, until recently, PHP.)

Pretty much everything else I can't live without is ubiquitous in modern general-purpose languages. A discussion of what features you can live without might be just as interesting, and probably more controversial.

Answer 78

LinkedHashMap. Use them once and you will love them forever.

Answer 79

Good user community!

Answer 80

I can't live without introspection anymore...

Answer 81

good documentation

php and python, java

Answer 82

Generics and LINQ

Answer 83

meta-programming features: -runtime class and methods definition (ruby) -method_missing , being able to catch all calls to non-defined method and act with a custom logic (eg: ActiveRecord dynamic finders)

Answer 84

Without a doubt, the one feature that I just can not live without is variables.

Answer 85

I require sensible rules for the declaration of variables. This specifically excludes old time Fortran, with the I-N (?) implicit integer rule. I hated that so much that there is a tumor in my brain at the location of the memory. Well, back to the current century...

The "sensible rules" feature has several components, so I can mention several things, right? A language must have declaration scoping - the ability to keep variable names local to a block of code. Even assembler languages must have local code labels (branch points); The language must be able to flag (or deny) implicit declarations, and detect the use of a variable before initialization.

Answer 86

Destructors

[extra characters to exceed limit 15]

Answer 87

var keyword in c#

Answer 88

I can live without just about anything. Starve me of anonymous functions, make me manage memory without even malloc/free, omit arithmetic or Booleans - fine, if there is some point to the restriction. Absence of both iteration, backwards branches, and recursion: yes, that too.

One thing, though: I think I do want something corresponding to conditionals, be it an if test facility, or lambda-calculus-like true and false combinators, or sh-like &&s and ||s on exit status. Without that, well, it's not really programming, is it.

Answer 89

Closures, closures and closures. I also come from the Ruby world and I am now using Scala, I can say that the Scala's type system is something I really love. It makes it easier to test, since all type related things are tested by the Scala compiler. Also, Erlang's and Scala's Actors are really really nice. :)

Answer 90

Symbolic representation - I just don't fancy machine code.

Answer 91

Deterministic destruction of objects (as in C++ and Delphi, unlike Java and .NET), typesafe containers, static type system are some of the most improtant features to me.

Answer 92

polymorphism & heritage

Answer 93

Strings

As funny as it may sound, certain languages lack proper official/standard/renowned string support, namely C (especially) and C++. In other languages, strings look like a last minute add-on class (namely Java), others portray it beautifully, namely Delphi, PHP and Javascript.

Some people prefer a large array of choices, such as the hundreds of string options in C++ (std::str, QString, nsString, gchar* and char*, to name a few).

Others prefer a more low level approach, such as C's chars, where you manually allocate memory when concatenating (and calling such functions to do this stuff).

Personally, I prefer the easy approach, where "a"+"b"=="ab", regardless of object reference, or any other limiting language construct.

Doesn't exist yet? Many interpreted languages do this by default. Some compiled languages, such as Delphi, has supported this from day one.

Why does bad habits keep on being transmitted forward?* It is the dependence on these low-level (and bad) coding that result in many of the known buffer overflows etc.

* Even as I speak, "modern" institutions still teach undergraduates (ie people with their next step in life being "work") the use of strings via C's char*!!

Answer 94

Statically typed