Having fun with V Lang

Tiny V Lang Essay

created: 12.MAR.2023

I love to learn new programing languages, it help to open the mind to new possibilities and compare different approaches. For instance, I learned Ruby and Scala in 2010, Clojure and Haskell in 2011, Go in 2015, Kotlin 2016, Rust in 2018 and Idris, TypeScript in 2019, 2020 Pandemic strike did a bunch of pocs but not with new langs(crazy year), Zig in 2021, 2022(coding in lots of langs but nothing new) - in 2023 I'm learning Nim and V. Learn at least one lang per year. This post is not complain, it's just to share some toughts, notes and impressions.

Why V

Simple: Very similar to Go (V compiler uses LLVM but originally written in Go)
Statically typed and compiled programming language
Fast: C interop with no cost, compiles to native binaries, as fast as C
Compiled: V backend compile to readable C. Web Server binary its only 250kb. V in writen in V and compile it self under a second, compiler is single thread, will 2-3x faster in the future. Compiler is less than 1MB, it is able to compile in less than a second about 1 million lines
Open Sourced in June 2019 by Alex Medvedniko
You can play with it here: https://play.vlang.io/

My Feelings (12.MAR.2023 v-lang version 0.2.4)

Has a REPL, all langs should have
Generates C so is like Scala, Clojure, Kotlin to Java or CoffeeScript,TypeScript to JavaScript.
Very cool and fun lang to code. Really like coding with it, more than Go.
Imuutable by default, can make it mutable iwith mut (great choise, like Scala)
Really cool that has tests, package manaer(mpm) inside the box.
Like Go has: Channels and JSON support also neat.
Memory Mgmt: V has an auto-free engine(compiler insert free call), remaning is handle by reference counting.
If you know Go, is very fast learning curve
Eco-system is very new, weak point but there is some libs: https://github.com/vlang/awesome-v. New langs have this issue.
Documentation is very raw, missed exmamples and deeper explanations - New langs have this issue.
C to V translatiom is pretty cool(https://github.com/vlang/c2v) - there is doom ported to V: https://github.com/vlang/doom
IMHO this is not good(not a big fan on ORM): V has a built-in ORM supports SQLite, MySQL and Postgres.
Like Rust has: unsafe
V has __global ( ) the good thing is that is not default. You need to turn it on.
I hope the lang grows, have more companies using.

Show me the code

My POCs with V: https://github.com/diegopacheco/v-playground

1 - Similar to Rust, precise memory types

i8, i16, i64, int, u8, u16, u32, u64

i := u8(1)
mut x := i64(1)

2 - Powerfull Array options

len: Number of pre-alocated elements in memory.
cap: ammount of memory space reserved for elements. Array can grow to this size without being re-allocated.

mut a := []int{len: 1000, cap: 10000, init: 0}

Arrays has several other bult-in functions like: repeat, insert, prepend, trim, clear, first, last, pop, reverse. Like Go, Zig and Rust you can get a Slice of an array

nums := [0, 10, 20, 30, 40]
println(nums[1..4])

3 - Type System

Similar to TypeScript in some way like this:

struct Point {
	x int
	y int
}
struct Line {
	p1 Point
	p2 Point
}

type ObjectSumType = Line | Point

V has Union as well.

4 - Strings, not as complicated as Rust and Zig

In V, a string is a read-only array of bytes. All Unicode characters are encoded using UTF-8. String values are immutable. You cannot mutate elements. But you can concated with other strings(if mut).

mut s := 'hello 🌎' // emoji takes 4 bytes
assert s.len == 10
s += " ok"
println("s value is ${s}")

state := 'akaska'
println(state[0])              // Output: 97
println(state[0].ascii_str())  // Output: a

println("I can cast to int like this: ${"42".int()}")

5 - runes

Cool name, have to admit. Single unicode chat, alias for u32
U use runes by using (backticks) ``

rocket := `🚀`
println(rocket)

V has several other cool features like (in operator like Python), enums like most of langs, Pattern Matcher(match),
Support for Collections on std lib(vlib) for Maps, Sets, LinkedLists, Trees, etc...

6 - Functional Programing, High Order Functions, Immutability, Lambdas

Like any good modern lang, you see functional programing elements here.

println([1, 2, 3, 4, 5, 6, 7, 8, 9, 10].filter(it%2==0).map(fn (i int) int { return i+1 } )) 
// prints: [3, 5, 7, 9, 11]

You can also do .any() or .all()

7 - For Loops like Go

names := ['John', 'Peter']
for i, name in names {
   println('${i}) ${name}')
  // Output: 0) John
  //         1) Peter
}

Can also use "_" to ignore a variable, just like Go.
We can use Ranges in for( i in 1 .. 5), conditional fors, C-style for.

7 - Heap Struct

Structs by default are allocated on the Stack but you can allocate on the heap by insing: "&".

struct Point {
	x int
	y int
}
p := &Point{10, 10}
println(p.x)

We can make files required with "[required]". Anonnimous structs are also avaliable.

Similar to Rust, we can add methods/functions in Structs

struct MarryableUser {
   age int
}
fn (u User) can_register() bool {
	return u.age > 21
}

We also have Interfaces, that can define fields and methods.

interface Animal {
  name string
  makeSound() string
}

diegopacheco/Having.fun.with.V.Lang.md