Haskell vs. JavaScript vs. Pascal vs. PureScript Comparison Chart

Every expression in Haskell has a type that is determined at compile time. All the types composed together by function application have to match up. If they don't, the program will be rejected by the compiler. Types become not only a form of guarantee, but a language for expressing the construction of programs. Every function in Haskell is a function in the mathematical sense (i.e., "pure"). Even side-effecting IO operations are but a description of what to do, produced by pure code. There are no statements or instructions, only expressions that cannot mutate variables (local or global) nor access state like time or random numbers. You don't have to explicitly write out every type in a Haskell program. Types will be inferred by unifying every type bidirectionally. However, you can write out types if you choose, or ask the compiler to write them for you for handy documentation.

Pascal is a procedural and imperative programming language. Pascal is a simple and efficient programming language designed for developers that want to build applications in structured ways. Free Pascal is a mature, versatile, open source Pascal compiler. It can target many processor architectures: Intel x86 (16 and 32 bit), AMD64/x86-64, PowerPC, PowerPC64, SPARC, SPARC64, ARM, AArch64, MIPS, Motorola 68k, AVR, and the JVM. Supported operating systems include Windows (16/32/64 bit, CE, and native NT), Linux, Mac OS X/iOS/iPhoneSimulator/Darwin, FreeBSD and other BSD flavors, DOS (16 bit, or 32 bit DPMI), OS/2, AIX, Android, Haiku, Nintendo GBA/DS/Wii, AmigaOS, MorphOS, AROS, Atari TOS, and various embedded platforms. Additionally, support for RISC-V (32/64), Xtensa, and Z80 architectures, and for the LLVM compiler infrastructure is available in the development version. Additionally, the Free Pascal team maintains a transpiler for pascal to Javascript called pas2js.