When comparing Pascal / Object Pascal vs Haskell, the Slant community recommends Pascal / Object Pascal for most people. In the question“What is the best programming language to learn first?” Pascal / Object Pascal is ranked 15th while Haskell is ranked 26th. The most important reason people chose Pascal / Object Pascal is:
Pascal / Object pascal was used in schools during the 2000's to teach kids the basics of object oriented programming.
Ranked in these QuestionsQuestion Ranking
Pascal / Object pascal was used in schools during the 2000's to teach kids the basics of object oriented programming.
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 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.
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 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 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 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++.
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 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 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 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 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 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 Automatic Memory Management
The new Delphi compilers are powered by Automatic Reference Counting to ease development.
Pro Excellent Database development
Pro Incredible GUI design tools
Lazarus and Delphi are both incredible GUI design tools, making rapid development a reality.
Making changes to a GUI doesn't mean switching tools or waiting for things to load, it's right there as part of your core tools.
Pro Available on a ridiculous number of platforms
FreePascal is available on/for Intel x86 (including 8086), AMD64/x86-64, PowerPC, PowerPC64, SPARC, ARM, AArch64, MIPS and the JVM. Supported operating systems include Linux, FreeBSD, Haiku, Mac OS X/iOS/iPhoneSimulator/Darwin, DOS (16 and 32 bit), Win32, Win64, WinCE, OS/2, MorphOS, Nintendo GBA, Nintendo DS, Nintendo Wii, Android, AIX and AROS.
Pro Component based (reusability, decoupled, rich design architecture)
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 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 Dynamic evolution of language.
Pro Forces you to learn pure functional programming
It is pure and does not mix other programming paradigms into the language. This forces you to learn functional programming in its most pure form. You avoid falling back on old habits and learn an entirely new way to program.
Pro Highly transferable concepts
Haskell's referential transparency, consistency, mathematics-oriented culture, and heavy amount of abstraction encourage problem solving at a very high level. The fact that this is all built upon little other than function application means that not only is the thought process, but even concrete solutions are very transferable to any other language. In fact, in Haskell, it's quite common for a solution to simply be written as an interpreter that can then generate code in some other language. Many other languages employ language-specific features, or work around a lack of features with heavy-handed design patterns that discourage abstraction, meaning that a lot of what is learned, and a lot of code that is needed to solve a particular problem just isn't very applicable to any other language's ecosystem.
Pro Referentially transparent
Haskell's Purely Functional approach means that code is referentially transparent. This means that to read a function, one only needs to know its arguments. Code works the same way that expressions work in Algebra class. There's no need to read the whole source code to determine if there's some subtle reference to some mutable state, and no worries about someone writing a "getter" that also mutates the object it's called on. Functions are all directly testable in the REPL, and there's no need to remember to call methods in a certain order to properly initialize an object. No breakage of encapsulation, and no leaky abstractions.
Pro Open source
All Haskell implementations are completely free and open source.
Pro Hand-writeable concise syntax
Conciseness of Haskell lets us to write the expression on the whiteboard or paper and discuss with others easily. This is a strong benefit to learn FP over other languages.
Pro Very few language constructs
The base language relies primarily on function application, with a very small amount of special-case syntax. Once you know the rules for function application, you know most of the language.
Pro Quick feedback
It's often said that, in Haskell, if it compiles, it works. This short feedback loop can speed up learning process, by making it clear exactly when and where mistakes are made.
Pro Functions curry automatically
Every function that expects more than one arguments is basically a function that returns a partially applied function. This is well-suited to function composition, elegance, and concision.
Pro Mathematical consistency
As Haskell lends itself exceedingly well to abstraction, and borrows heavily from the culture of pure mathematics, it means that a lot more code conforms to very high-level abstractions. You can expect code from vastly different libraries to follow the same rules, and to be incredibly self-consistent. It's not uncommon to find that a parser library works the same way as a string library, which works the same way as a window manager library. This often means that getting familiar and productive with new libraries is often much easier than in other languages.
Pro Easy to read
Haskell is a very terse language, particularly due to its type inference. This means there's nothing to distract from the intent of the code, making it very readable. This is in sharp contrast to languages like Java, where skimming code requires learning which details can be ignored. Haskell's terseness also lends itself to very clear inline examples in textbooks, and makes it a pleasure to read through code even on a cellphone screen.
Pro Popular in teaching
Haskell is really popular in universities and academia as a tool to teach programming. A lot of books for people who don't know programming are written around Haskell. This means that there are a lot of resources for beginners in programming with which to learn Haskell and functional programming concepts.
Pro Easy syntax for people with a STEM degree
Since the basic syntax is very similar to mathematics, Haskell syntax should be easy for people who have taken higher math courses since they would be used to the symbols used in maths.
Pro Powerful categorical abstractions
Makes categorical higher order abstractions easy to use and natural to the language.
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 Unnecessary heavy syntax
Begin.. end. Pascal would have been great with curly braces.. but then again, that's what C is for. It's an academic language which was used in the past, but not much anymore today.
Con All variables, types, constants and functions must be declared at the beginning of the code
Con Difficult learning curve
Haskell lends itself well to powerful abstractions - the result is that even basic, commonly used libraries, while easy to use, are implemened using a vocabularly that requires a lot of backround in abstract mathematics to understand. Even a concept as simple as "combine A and B" is often, both in code and in tutorials, described in terms of confusing and discouraging terms like "monad", "magma", "monoid", "groupoid", and "ring". This also occasionally bears its ugly head in the form of complicated error messages from type inference.
Con Symbols everywhere
Haskell allows users to define their own infix operators, even with their own precedence. The result is that some code is filled with foreign looking operators that are assumed to be special-case syntax. Even for programmers who know they're just functions, operators that change infix precedence can potentially break expectations of how an expression is evaluated, if not used with care.
Con Language extensions lead to unfamiliar code
Haskell's language extensions, while making the language incredibly flexible for experienced users, makes a lot of code incredibly unfamiliar for beginners. Some pragmas, like NoMonomorphismRestriction, have effects that seem completely transparent in code, leading beginners to wonder why it's there. Others, like ViewPatterns, and particularly TemplateHaskell, create completely new syntax rules that render code incomprehensible to beginners expecting vanilla function application.
Con Package manager is unstable & lacking features
Cabal (There are other choices but this is the most popular) can not uninstall a package. Also working at a few locations it is difficult to have the same environment for each one be the same.
Con You have to learn more than just FP
Haskell is not only a functional language but also a lazy, and statically typed one. Not only that but it's almost necessary to learn about monads before you can do anything useful.
Con Obscure ugly notation
0 = 1
Using "=" like this: <code>
-- Using recursion (with pattern matching)
factorial 0 = 1
factorial n = n * factorial (n - 1) </code> Example from https://en.wikipedia.org/wiki/Haskell_(programming_language)
is quite simply annoying aesthetics.
Con You need some time to start seeing results
Haskell's static typing, while helpful when building a project, can be positively frustrating for beginners. Quick feedback for errors means delaying the dopamine hit of code actually running. While in some languages, a beginner's first experience may be their code printing "Hello World" and then crashing, in Haskell, similar code would more likely be met with an incomprehensible type error.
Con Lazily evaluated
Haskell's lazy evaluation implies a level of indirection - you're not passing a value, you're passing a thunk. This is often difficult to grasp not just for beginners, but for experienced programmers coming from strictly evaluated languages. This also means that, since for many, strict evaluation is their first instinct, initial expectations of a function's performance and complexity are often broken.
Con Too academic, hard to find "real world" code examples
Con Only pure functional programming
Not proper functional programming but a subset of the style called pure functional programming.
Con Documentation for most packages is short and lacking
A few Haskell packages are well documented but this is the exception, not the rule.
Most of the time a list of function signatures is what passes for documentation.