Vork

Vork will eventually be a fully fledged V implementation.

Right now it is just a parser, once I get a full parser then I will start working on code gen.

Example

for now all that it does is read in a file and try to parse it. Right now there is no error recovery on a syntax error, but there is a nice printout so you can hopefully understand what went wrong.

The parse output will be printed and is formated in a lisp like way

fn fib(n int) int {
        if n <= 1 {
                return n
        }
        return fib(n - 1) + fib(n - 2)
}

fn main() {
        i := 0
        for i = 0; i < 10; ++i {
                println(fib(i))
        }
}

(func fib ((n int)) int
  (block
    (if (<= n 1)
      (block
        (return n)))
    (return (+ (call fib ((- n 1))) (call fib ((- n 2)))))))
(func main () 
  (block
    (var (i) 0)
    (for (= i 0) (< i 10) (prefix ++ i)
      (block
        (call println ((call fib (i))))))))

Formal grammar

The lark file has an old formal grammar I defined which I am going to keep as a reference, maybe after finishing the hand written parser I will go back and rewrite the formal grammar to be updated.

hopefully by the done I am finished with the parser the (official) formal grammar will be out already 🤷

Implemented

• All binary and unary expressions
  • post fix operators are not added to the ast yet
  • Function calls can not take mut modifier to expression for now
• Almost full type parsing support
  • missing function types
• Functions, methods and interop functions
  • missing generics
  • missing multiple return value
  • missing auto wrapping of optional values
• Module and Imports
• Structs with their access modifiers
  • missing the base type
  • missing generics
• asserts
• if\if else\else
• Most of the for loops
  • in c like for loops can not declare a variable at the start...
  • missing for with only condition (for true)
• Constants
• Variable declarations
• Enums declarations
• Integer, Float and arrays literals
• or statement
• Super basic type checking
  • missing mut checks
  • missing unsafe checks
  • missing access checks (pub)
  • missing implicit enum

Missing

• string and map
• interfaces
• match
• go statement
• attributes
• compile time if

Problems

Right now the parser ignores new lines completely, that is because from what I could see the official V compiler also does that, but in an inconsistent way... sometimes it ignores it and sometimes not...

for the most part it is not actually a problem, but specifically for the * operator it makes a problem, because it is used both for deref and for multipication

a := 123
b := &a
*b = 456

will not give the correct output!

the simplest way to get around it for now is to simply seround it with a block

a := 123
b := &a
{*b = 456}

but the real solution is to wait for a formal grammar and see how newlines should actually be handled.

note that this problem happens on any operator which may be used in both unary and binary way, including - and alike...