Version: 0.62.0

Cheat Sheet

Strings

let name: string = "Tezos";

Characters

let t: string = "t";

Integers

let i: int = 42;

Natural numbers

let n: nat = 7 as nat;

Unit

let u: unit = unit;

Boolean

let has_drivers_license: bool = false
let adult: bool = true

Boolean Logic

let booleanLogic: bool =
    (!true) ==
    false ==
    (false && true) ==
    (false || false)

Mutez (micro tez)

let tez: tez = 42 as tez
let tez2: tez = 7 as mutez

Address

let tz1address: address =
  "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" as address;
let kt1address: address =
  "KT1JepfBfMSqkQyf9B1ndvURghGsSB8YCLMD" as address;

Addition

let add_int: int = 3 + 4;
let add_nat: nat = (3 as nat) + (4 as nat);

Multiplication & Division

let mul_int: int = 3 * 4;
let mul_nat: nat = (3 as nat) * (4 as nat);

let div_int: int = 10 / 5;
let div_nat: nat = (10 as nat) / (5 as nat);

Modulo

let mod_nat: nat = 10 % 3

Tuples

type name = [string, string]

let winner: name = ["John", "Doe"]

let firstName: string = winner[0]
let lastName: string = winner[1]

Types

type age = int
type name = string

Includes

#include "library.jsligo"

Functions (short form)

let add = (a: int, b: int): int =>
  a + b;

Functions (long form)

let add = (a: int, b: int): int => {
  let c = a;
  let d = b;
  return c + d
};

If Statement

let if_statement = (age : nat): string => {
  if (age >= (16 as nat)) { return "yes"; } else { return "no"; }
}

Options

type middle_name = option<string>;
let middle_name : middle_name = Some("Foo");
let middle_name_ : middle_name = None();

Variable Binding

let age: int = 5

Type Annotations

let someAddress: address =
  "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" as address;

Variants

type action =
  ["Increment", int]
| ["Decrement", int];

Variant *(pattern)* matching

let a: action = Increment(5)
let result: int = match(a, {
  Increment: (n: int) => n + 1,
  Decrement: (n: int) => n - 1
})

Records

type person = {
  age: int,
  name: string
}

let john : person = {
  age: 18,
  name: "john doe"
}

let name_: string = john.name

Maps

type prices = map<nat, tez>;

let prices: prices = Map.literal(list([
  [10 as nat, 60 as mutez],
  [50 as nat, 30 as mutez],
  [100 as nat, 10 as mutez]
]));

let price: option<tez> = Map.find_opt(50 as nat, prices)

let prices2: prices = Map.update(200 as nat, (Some (5 as mutez)), prices)

Contracts & Accounts

let destinationAddress: address =
  "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" as address;

let contract : contract<unit> =
  match (Tezos.get_contract_opt(Tezos.get_sender()) as option<contract<unit>>, {
    Some: (contract: contract<unit>) => contract,
    None: () => (failwith("no contract") as contract<unit>)
  })

Transactions

let payment: operation =
  Tezos.transaction(unit, 100 as mutez, contract);

Exception/Failure

let fail = (u: unit) : unit =>
  failwith("a failure message")