lark

Documentation

types

• int
• float
• boolean
• string

variable initialization

a <- 1;
b <- "lark";
c <- 3.14;
d <- true;
e <- 123;
f <- (1+2+3) + c + (3*1/10);
arr <- [1,2,3];
firstElement <- arr@0;
thirdElement <- arr@2;
unary <- !false;

operators

*, /, (
+, -
>, <, >=, <=, !, !=

control-flow

a <- (1+3)==2; // false
b <- true;
if (a==b) <<
  c <- "ok";
>> else <<
  c <- "not_ok";
>>

swap variables

a <- 1;
b <- -123;
a <-> b;
/* a = -123, b = 1 */

functions

fn addStaticVars[] <<
  return 100+500;
>>

fn addWithNoReturn[] <<
  a <- 100;
>>

fn addWithArgs[a,b] <<
  return a+b;
>>

fn addWithArgsAndLocalVar[a,b] <<
  local c <- 3;
  return a+b+c;
>>

fn addWithDynamicArgs[a,b] <<
  return a+b;
>>

fn addWithStaticAndDynamicArgs[a,b] <<
  return a+b;
>>

fn addArrayElements[arr] <<
  return arr@0 + arr@1;
>>

addWithNoReturn();
staticsum <- addStaticVars();
sumOne <- addWithArgs(1, 2); // 3
sumTwo <- addWithArgsAndLocalVar(1, 2); // 6

first <- 100;
second <- 200;
sumThree <- addWithDynamicArgs(first+(5-3)*second, second); // 700

sumFour <- addWithStaticAndDynamicArgs(first, 2000); // 2100

arr <- [1,2];
arrSum <- addArrayElements(arr);
arrSumViaArgs <- addWithArgs(arr@0, arr@1);

if (arr@0 == 1) <<
  equals <- "equals 1";
>>

Usage

Using Makefile

make run

Source

go build -o lark && ./lark <filename>

Progress Board

Also read: https://manosriram.com/posts/writing-an-interpreter/