When comparing Pascal / Object Pascal vs Clojure, the Slant community recommends Clojure for most people. In the question“What is the best programming language to learn first?” Clojure is ranked 7th while Pascal / Object Pascal is ranked 13th. The most important reason people chose Clojure is:
Clojure programmers are highly encouraged to use immutable data in their code. Therefore, most data will be immutable by default. State change is handled by functions (for transformations) and atoms (an abstraction that encapsulates the idea of some entity having an identity).
Ranked in these QuestionsQuestion Ranking
Pro Understanding of basics
Because of the verbosity and easy syntax, Pascal language is relatively easier to be learned and understood, even for someone who has no programming knowledge. It's said that Pascal code —if written well— is like reading pseudo code.
Pro Cross platform
Pro Clear syntax
Pascal's syntax is clear and concise, for example:
procedure test(); begin DoSomething(); end;
Pro Fast compilation
The compiler is fast, really fast. Compared to C/C++, the delphi compiler is designed to compile a decent sized desktop application in seconds rather than minutes.
Pro Enforces good programming practice
Numerous strong compile time checks with optional runtime checks ensure one doesn't do stupid things and even when one does (because the compiler can't prove it at compile time), the binary will check and report it at runtime.
Correct modular programming implementation with proper namespacing, no file inclusion hack.
Pascal / Object pascal was used in schools during the 2000's to teach kids the basics of object oriented programming.
Using the Free Pascal Compiler (the main Pascal distribution) you can code in a language that can be procedural and imperative now, but it can became object-oriented simply adding a directive at the start of the source
Pro Easy GUI creation
Visual Basic may have predated Delphi but Delphi was the ground breaking visual designer which set the standards expected today by most GUI developers. Its rich component set was well designed, structured and extensible, it even has the ability to display live data from the attached database in its data controls.
Pro Tons of academic reading
Being known as the programming language for education, especially in the 90's, there many academic reading and tutorials available on the internet.
Pro Assembler Code and DLL/SO creation
You can put Assembler code in Intel or AT&T formats, to achieve great results of speed and accuracy. It is possible to create Dynamic Link Libraries or their equivalent in Unix-like systems so it's relatively easy to use and powerful.
Pro Rich existing libraries
Both shipped with implementations and spread all over the web. Both natively written or bindings to libraries written in other languages. Typically to build non-trivial applications there's no need to surf the web as many things are implemented already. Streaming, output templating, socket & networking, web, database, image manipulation, high performance graphics, (de)compression, (de|en)cryption, regex, unit testing, json manipulation, google API, indexing, multithreading, external process management, the list just goes on and on!
Pro Well balanced for desktop development
For desktop development, Delphi is productive, the code is easy to understand, compilation speed is blazing, and it produces well performing applications that are easy to deploy. The perfect balance between C# and C++.
Pro Still active
From the early roots of Pascal, Delphi has been developed and is still actively supported. It is used in many desktop applications today, and even supports multi platform coding.
Pro Fast execution
The compiler generates fast and optimized code. No stop-the-universe garbage collection.
Pro Extensive third party libraries
There are large collections of third party components, many free which enable developers to add wide ranging and complex functionality to their code with ease
Pro Automatic Memory Management
The new Delphi compilers are powered by Automatic Reference Counting to ease development.
Pro Language depth
Object Pascal is being used to write custom kernels (Ultibo) and operating-systems for various ARM boards. So the way you work with the code scales from low-level to pure OOP high-level. Object Pascal has the same level of depth that you find in C/C++ but with added productivity.
Pro Reliable language and code base
Most code from the Turbo Pascal days in the 80s still compiles, yet the language has since been adapted and extended with modern concepts, introducing OOP and interfaces, exception handling, native Unicode support, anonymous methods, generics, ARC and more.
Pro Suitably close to modern languages, without the pitfalls
It was developed as a teaching language and it shows. No syntax pitfalls and gently encourages good style.
Pro Component based (reusability, decoupled, rich design architecture)
Pro Dynamic evolution of language.
Pro Excellent Database development
Pro Immutability is the default
Clojure programmers are highly encouraged to use immutable data in their code. Therefore, most data will be immutable by default.
State change is handled by functions (for transformations) and atoms (an abstraction that encapsulates the idea of some entity having an identity).
Pro Minimal syntax
Being a LISP, programs are simple: they're just functions and data. That it doesn't get bogged down with syntax or the loftier FP concepts like monads makes it one of most approachable functional languages for beginners.
Pro Tries to solve problems as simply as possible
Simplicity is one of the pillars on which Clojure is built. Clojure tries to solve many problems in software development as simply as possible. Instead of building complex interfaces, objects or factories, it uses immutability and simple data structures.
Pro Good for writing concurrent programs
Since Clojure is designed for concurrency, it offers things like Software Transaction Memory, functional programming without side-effects and immutable data structures right out of the box. This means that the development team can focus their energies on developing features instead of concurrency details.
Pro Cross platform
Clojure compiles to JVM bytecode and runs inside the JVM. This means that applications written in Clojure are cross-platform out of the box.
Pro Huge ecosystem of libraries to work with
There's a very large ecosystem of high-quality Clojure libraries which developers can use. One example is Incanter. It's a great data analytics library and a very powerful tool for dealing with matrices, datasets and csv files.
Pro Dynamic language
A superb data processing language. While rich type and specification systems are available they are optional.
Pro Rich Hickey
The creator is so awesome, he's a feature. Just look up his talks and see why.
Clojure has an elegant macro system which enables language additions, Domain-specific languages (DSLs), to be created much easier than most other languages (with the exception of Racket, perhaps).
Pro Great tool used in automating, configuring and managing dependencies available
Leiningen is a very useful tool for Clojure developers. It helps wiht automation, configuration and dependency management. It's basically a must for every Clojure project.
Pro Game is available with which you can learn Clojure
Nightmod is a tool used to make "live-moddable" games. It displays the game's code while you are playing and allows you to inject new code using Clojure. This can be a fun and useful experience for people trying to learn Clojure.
Pro No C/Java syntax
Con Niche language
Most use of this language will be found in jobs supporting legacy code. It will be hard to find things to do with this language outside of that niche.
Con No up-to-date version of language standards
In 1983, and update in 1990, the language was standardized with two standards: ISO/IEC 7185:1990 Pascal and ISO/IEC 10206:1990 Extended Pascal. However, Object Pascal extensions to the language have no official standards but in 1993, a draft proposal for object oriented Pascal standard was re; for review purposes only. There are no standards for modern features and enhancements, thus various Pascal dialects like Delphi or HP Pascal has their own enhancements and features.
Con All variables, types, constants and functions must be declared at the beginning of the code
Con Unnecessary syntax
Con Focus on syntax bloat over actual program logic.
Con Confusing error messages
Clojure's error messages more often than not are very confusing. They usually involve stack traces that do not thoroughly explain where the error was caused or what caused it.
Con Syntax can be alien / jarring for those used to other Lisps
Perhaps some may consider this attribute an advantage, but I do not. Clojure does not attempt to maintain significant compatibility with other Lisps. So, if you already know a Lisp or are used to the way Lisp works in general, you'll probably be confused if you take a look at Clojure. See these resources for more details on this subject:
Con Tied to the JVM and it's limitations.
Some language constructs were obviously created as workarounds for JVM limitations. This makes the language much less elegant than it could have been.
Also, the JVM has a very cumbersome FFI.