lsts-syntax.md

Syntax Reference

Literal Values

true           # Boolean
1              # Integer
1.2            # Floating Point Integer
"abc"          # String
'a'            # Character
r/a*b+c/       # Regular Expression

Function Application

f(a, b)

Field Access

a.field

Method Call

a.method(b,c)

Array Indexing, Byte Indexing, Item Indexing

arr[i]       # Get one item
arr[i:j]     # Get slice from i until j
arr[:j]      # Get slice from start until j
arr[i:]      # Get slice from i until end
arr[i:-2]    # Get slice from i until 2 items before end

Struct Constructor

A { 1, 2, 3 }

Sequenced Expressions

do-this();     # The semi-colon separates expressions into an ordered sequence
before-this();

Let

let x = 5;

Variable Assignment

x = 6;

If

if x then y;
if x then y else z;
if x { y };
if x { y } else { z };

While

while condition { do-a-thing; };

For

for x in y { do-a-thing; };

Match

match a {
   lhs => rhs;
   "abc" => "def";           # match a string value "abc"
   "ab".. rest => "c";       # match a string starting with "ab"
   [1.. 2..] => 3            # this lhs will match only a two element sequence [1,2]
   [1.. 2.. _] => 3          # this lhs will match any sequence starting with 1 and 2
   A { binding=key:5 } => 4; # this will match a struct A with field "key" having value 5
};

Function Definition

let f(a: A, b: B): C = c(a, b);

Method Definition

let .f(this: A, b: B): C = c(this, b);

Type Definition

type AB = CaseA { x: U64 } | CaseB { y: U64 };