tez

LIGO offers some Tezos-specific data types. Here we list some of them. Others have their own dedicated section.

The token unit on Tezos is called tez in LIGO. There are several ways to write literal values of type tez:

• units of millionth of tez, using the suffix mutez after a natural number, like 10000mutez or 0mutez;
• units of tez, using the suffix tz or tez, like 3tz or 3tez;
• decimal amounts of tz or tez, like 12.3tz or 12.4tez.

The type is tez, not mutez --- which is a suffix to write literals.

Note that large amounts, like with numerical values of type int and nat, can be expressed using underscores to separate groups of digits, like 1_000mutez (one thousand mutez) or 0.000_004tez.

Adding

Addition in LIGO is accomplished by means of the + infix operator. Some type constraints apply, for example you cannot add a value of type tez to a value of type nat.

In the following example you can find a series of arithmetic operations, including various numerical types. However, some bits remain in comments as they would otherwise not compile, for example, adding a value of type int to a value of type tez is invalid. Note that adding an integer to a natural number produces an integer.

const sum: tez = 5mutez + 1tez;

Subtracting

Since subtracting two amounts could result in a negative amount, subtraction of two tez amounts result in an optional amount, like so:

const amount: option<tez> = 5mutez - 1mutez; /* Some (4mutez) */

const negative: option<tez> = 1mutez - 5mutez; /* None */

Multiplying

You can multiply nat and tez values:

const mult: tez = 5n * 5mutez;

Dividing

The division of two tez values results into a nat.

const div: nat = 10mutez / 3mutez;

Euclidean Division

For cases when you need both the quotient and the remainder, LIGO provides the ediv operation. ediv(x,y) returns Some (quotient, remainder), unless y is zero, in which case it returns None. The function ediv is overloaded to accept tez, beyond all the combinations of natural and integer numbers:

// Some (7, 2mutez)

const ediv1: option<[nat, tez]> = ediv(37mutez, 5mutez);

// Some (7mutez, 2mutez)

const ediv2: option<[tez, tez]> = ediv(37mutez, 5n);