Efficient, expressive, elegant
Nim is a statically typed compiled systems programming language. It combines successful concepts from mature languages like Python, Ada and Modula.
Efficient
- Nim generates native dependency-free executables, not dependent on a virtual machine, which are small and allow easy redistribution.
- The Nim compiler and the generated executables support all major platforms like Windows, Linux, BSD and macOS.
- Nim's memory management is deterministic and customizable with destructors and move semantics, inspired by C++ and Rust. It is well-suited for embedded, hard-realtime systems.
- Modern concepts like zero-overhead iterators and compile-time evaluation of user-defined functions, in combination with the preference of value-based datatypes allocated on the stack, lead to extremely performant code.
- Support for various backends: it compiles to C, C++ or JavaScript so that Nim can be used for all backend and frontend needs.
Expressive
- Nim is self-contained: the compiler and the standard library are implemented in Nim.
- Nim has a powerful macro system which allows direct manipulation of the AST, offering nearly unlimited opportunities.
Elegant
- Macros cannot change Nim's syntax because there is no need for it — the syntax is flexible enough.
- Modern type system with local type inference, tuples, generics and sum types.
- Statements are grouped by indentation but can span multiple lines.
import strformat
type
Person = object
name: string
age: Natural # Ensures the age is positive
let people = [
Person(name: "John", age: 45),
Person(name: "Kate", age: 30)
]
for person in people:
# Type-safe string interpolation,
# evaluated at compile time.
echo(fmt"{person.name} is {person.age} years old")
# Thanks to Nim's 'iterator' and 'yield' constructs,
# iterators are as easy to write as ordinary
# functions. They are compiled to inline loops.
iterator oddNumbers[Idx, T](a: array[Idx, T]): T =
for x in a:
if x mod 2 == 1:
yield x
for odd in oddNumbers([3, 6, 9, 12, 15, 18]):
echo odd
# Use Nim's macro system to transform a dense
# data-centric description of x86 instructions
# into lookup tables that are used by
# assemblers and JITs.
import macros, strutils
macro toLookupTable(data: static[string]): untyped =
result = newTree(nnkBracket)
for w in data.split(';'):
result.add newLit(w)
const
data = "mov;btc;cli;xor"
opcodes = toLookupTable(data)
for o in opcodes:
echo o