When comparing D vs Lua, the Slant community recommends Lua for most people. In the question“What is the best programming language to learn first?” Lua is ranked 16th while D is ranked 28th. The most important reason people chose Lua is:
One of the best features of Lua is its very well designed C API. This is very useful if you have an existing C library you need to integrate with Lua or quickly get a Lua script running on the C side of the game. Finally Lua plays so nice with C that if you need to optimise for speed you can re-write it in C a lot easier than other languages.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Has an improved C subset
With few exceptions, D will either compile C code to work exactly as when compiled as C, or it won't compile - it won't quietly change the semantics of C code and give unexpected results. This means that D contains an improved C, as it fails compilation where type safety is missing in C.
This allows learning the same machine operations available in C and other low-level languages.
Pro Easy to read and understand code
Pro Doesn't force you to deal with memory management
When you're just starting out, dealing with manual memory management and its bugs is a huge pain! D is garbage collected by default, which removes a huge class of things that could go wrong. And later on, if you decide you don't want or need the GC, you can turn it off.
Pro Very fast compilation
D is usually up to 10 times faster than C++. Having a language that compiles this fast means that you are free to write highly optimized code because of the relatively low cost of experimentation.
Pro Unit testing built-in
D provides unittest blocks to insert code that verifies functions preform their expected behavior and document edge cases. Since these are enabled with a compiler switch, there is no need to teach new programmers how to install new libraries and import modules, instead training on test driven design can start from the very first function.
Pro Provides a powerful data structure on top of C's arrays called slices
D provides a structure that builds on C's arrays called slices. A slice is a segment of an array that tracks the pointer and the length of the segment.
Slices are extremely powerful because they combine the protection of knowing the length of the data with the garbage collector that manages the memory backing that data, thus avoiding most memory corruption issues.
Pro It's a state-of-art evolution of C
Pro Static with type inference
For a new user adding types can feel tedious, and takes focus off the meaning of the code, but they are also important for checking logic. D provides static types, and a good system to infer types, so types are checked when calling functions, but do not need to be specified everywhere, making it feel more dynamic.
Pro Provable purity and immutability
The compiler can check that functions don't have side effects, extremely important for functional programming in concurrent scenarios, and can check immutability.
Therefore, the compiler will prove that your programs are functionally pure and respect immutable data, if you want it to.
Pro Compile-time Function Execution
Pro Built-in Unicode support
Pro Industrial quality
Pro Asynchronous I/O that doesn’t get in your way
Because all types can be treated as objects, all files can call functions in the same manner -- even stdin
and stdout
. stdout.writeln();
stdin.readln();
file.writeln();
file.readln();
Pro Easy to integrate with C and C++
D practically has the same memory structure as C and C++; all D does it build a structure around that. The entire C standard library is accessible at no cost (syntactic or speed) and it's being worked on allowing the same for the C++ standard library.
Pro Designed for concurrency and parallelism
Supports first-class functionality for both concurrency and parallelism, offered as part of the standard library.
Pro Supports calling functions from types in an object-oriented manner.
if (exists(file)) {}
may be written as if (file.exists) {}.
writeln(file);
may be written as file.writeln();
isDivisibleBy(10, 2);
may be written as 10.isDivisibleBy(2);
writeln(isEven(add(5, 5)));
may be written as 5.add(5).isEven().writeln();
Pro Very easy to integrate with C and C++
One of the best features of Lua is its very well designed C API. This is very useful if you have an existing C library you need to integrate with Lua or quickly get a Lua script running on the C side of the game.
Finally Lua plays so nice with C that if you need to optimise for speed you can re-write it in C a lot easier than other languages.
Pro Great documentation
The official Lua documentation is very helpful and thorough. There are also a large number of online resources or books with lots of helpful information for beginners and advanced users alike.
Pro Portable
Lua can be built on any platform with a ANSI C compiler.
Other than that, Lua is extremely small. For example, the tarball for Lua 5.2.1 is only 245K compressed and 960K uncompressed (including documentation).
When built on Linux, the Lua interpreter built with the standard libraries takes 182K and the Lua library takes 243K.
The small size and the ability to build with a C compiler make Lua an extremely portable language that can run on a lot of different systems and computers.
Pro Simple
Easy to learn.
Pro Fast
Lua's performance compares very well to other languages, If performance needs to be further improved you can:
- Implement critical parts in C
- Use the LuaJIT compiler. The LuaJIT compiler is a drop in replacement for the stock compiler and provides significant performance improvements. From the overview page:
LuaJIT speeds can rival code written in C.
Pro Embeddable
Many different game engines (e.g. Elder Scrolls series, ToME) use Lua for scripting, and it's runtime is designed for embedded use.
Pro Clean and simple syntax suitable for beginners
The Lua syntax is modeled from Modula, a language known for being a fantastic introduction to programming.
The Lua syntax also has the following key characteristics:
- Semicolon as a statement separator is optional (mostly used to resolve ambiguous cases as in a = f; (g).x(a)).
- Syntactic sugar for function calls (f'string', f"string", f[[string]], and f{table}) and method calls (obj:m()).
Pro Helpful community
Due to the growing popularity, Lua has a rather large and helpful community surrounding it.
Cons
Con Poor adoption even after many years of existence
There's a widely accepted perception of D as a language that has been poorly adopted. Since adoption is driven by perception this becomes a fact. So managers and engineers start becoming nervous in adopting a language that has such a perception among the community and that has been so unsuccessful for so long.
Con Failed at becoming alternative to C or C++
Almost as confused and complicated as C++, but without the popularity and widespread corporate usage. Also failed at becoming a good cross-platform GUI application development language like Object Pascal. Many missed past opportunities, and now newer languages are better alternatives.
Con Lack of vision
D is community-driven and lacks the support of any large corporation. While this increases the amount of talent and engineering abilities of the people working on D, it also brings a severe lack of charisma, leadership and vision.
Con Garbage Collection
Memory is not managed directly.
Con All the downsides of garbage collection without any of its benefits
When D decided to implement garbage collection it instantly alienated a large community of developers (C and C++ programmers). For them, the official policy has been: "Don't want garbage collection? Use D with RAII or manual management style!".
While true, it's also absolutely pointless because there's little to none support for alternate memory management styles in the standard library, which means that a new user will have to start with a language that is stripped down of the core infrastructure.
On the other hand, for those people who want to use garbage collection, the implementation of it is lackluster.
Con Easy to make mistakes when declaring variables
When writing a function, if a programmer forgets to declare a variable, that variable will be declared at global scope. The code will seem to run fine at first, but if another function uses a variable with the same name, but fails to declare it, it will create subtle, incredibly difficult to find bugs.
Con Some concepts may not be applied to other "mainstream" programming languages
Lua features a prototye-based inheritance model. While this is also used by Javascript, it's not used by many other mainstream languages, and so some of the concepts learned while learning Lua won't be very applicable to other languages.
Another thing that makes Lua different from other programming languages, is the fact that Arrays start at 1 instead of 0. While helpful for beginners, it can complicate logic and make it very confusing when switching languages.
Con Batteries not included
Lua is so small mainly due to many of the components not being included in the core package. A lot of people need the functionality provided by the Lua module management system LuaRocks and libraries such as Penlight.