Introduction

Overview

Swirl is a statically-typed, LLVM-based systems programming language.

Kickstart

The main function is the entry-point of a Swirl program.

fn main(): i32 {  // the return type can be omitted as the type inference system can infer it
    return 0;
}

Variable Declarations

Variables can either be declared with let or var, the former doesn't allow reassignment and enforces in-place initialization, the latter does allow it.

let constant = 43;
let anothere_const: i8;  // error: initialization required
    
var my_var = 39;
my_var = 49;  // can be reassigned

Initialization Semantics: when a variable declaration is left uninitialized, it is automatically zero-initialized. If you do not want that to happen, initialize it with the undefined keyword.

var uninitialized: i16 = undefined;

Conditions

if a == b || c == d && e != f {
    ...
}

elif a == c {
    ...
}

else {
    ...
}

While Loop

while e != f {
    if e == g {
        break;
    } else {
        continue;
    }
}

Operators

Operator	Usage	Associativity	Precedence (Descending order)
.	Member access	Left	A
[]	Indexing	Left	B
&x	Address taking	Left	C
+x	Unary plus	Left	C
-x	Unary minus	Left	C
*x	Dereference	Left	C
!x	Logical not	Left	C
~x	Bitwise NOT	Left	C
as	Cast	Left	D
**	Exponentiation	Right	E
*	Multiplication	Left	F
/	Division	Left	F
%	Modulus	Left	F
+	Addition	Left	G
-	Subtraction	Left	G
<<	Bitwise left shift	Left	H
>>	Bitwise right shift	Left	H
>	Greater than	Left	I
>=	Greater than or equal	Left	I
<	Less than	Left	I
<=	Less than or equal	Left	I
==	Equality	Left	J
!=	Inequality	Left	J
&	Bitwise AND	Left	K
^	Bitwise XOR	Left	L
|	Bitwise OR	Left	M
&&	Logical AND	Left	N
||	Logical OR	Left	O
=	Assignment	Right	P
+=	Add assignment	Right	P
-=	Subtract assignment	Right	P
*=	Multiply assignment	Right	P
/=	Divide assignment	Right	P
%=	Modulus assignment	Right	P
**=	Exponentiation assignment	Right	P
|=	Bitwise OR assignment	Right	P
&=	Bitwise AND assignment	Right	P
^=	Bitwise XOR assignment	Right	P
<<=	Left shift assignment	Right	P
>>=	Right shift assignment	Right	P

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