Types

Michelson

Asset

add

remove

remove_if

remove_all

clear

[]

contains

count

nth

sort

sum

select

head

tail

`asset_container<A>`

Evaluates to the basic container type of collection of asset A.

The following table presents examples of the correspondance betweed asset collection and container types:

asset whitelist {
  user : address;
}

asset_container<whitelist> is evaluated to:

set<address>

asset data {
  owner : address;
  amount : nat
}

asset_container<data> is evaluated to:

map<address, nat>

asset data to big_map {
  owner : address;
  amount : nat
}

asset_container<data> is evaluated to:

big_map<address, nat>

asset whitelist to big_map {
  user : address;
}

asset_container<whitelist> is evaluated to:

big_map<address, unit>

Parameter

A

(asset)

Any declared asset.

Example

Properties

Michelson

Asset

asset_key

asset_value

`asset_key<A>`

Evaluates to the asset identifer type of collection A.

The following table presents examples of key type evaluation:

asset whitelist {
  user : address;
}

asset_key<whitelist> is evaluated to:

address

asset data {
  owner : address;
  amount : nat
}

asset_key<data> is evaluated to:

address

asset ledger identified by owner tokenid {
  owner     : address;
  tokenid   : nat;
  amount    : nat = 0;
}

asset_key<ledger> is evaluated to:

record ledger_key {
  owner     : address;
  tokenid   : nat;
}

Parameter

A

(asset)

Any declared asset.

Example

Properties

Michelson

Asset

asset_container

asset_value

`asset_value<A>`

Type of an asset value generated from asset declaration. An asset value is a record that provides all asset fields but the asset identifier field(s).

Consider for example the following asset declaration:

asset result {
  id    : string;
  score : nat;
  time  : duration;
}

The asset value for result is the record with score and time fields. Hence asset_value<result> is equivalent to the following declaration:

record ledger_asset_value {
  score : nat;
  time  : duration;
}

An asset record value is returned by the [] asset method (and get). As for any record, fields are accessed normally with . operator:

const v : asset_value<result> = result["#sub001"];
const s = v.score;
const t = v.time;

Parameter

A

(asset)

Any declared asset.

Example

Properties

Michelson

Asset

asset_container

asset_key

[]

get

`asset_view<A>`

Read-only view on asset collection returned by asset methods: sort select head tail

Consider for example the following asset declaration:

asset vehicle {
  vin: string;
  nbdoors : nat = 0
}

The asset view of vehicles with 5 doors is created with method select:

const sedan = vehicle.select(the.nbdoors = 5)

It is possible to iterate on an asset_view with the for instruction.

For example:

for v in sedan do
 /* ... */
done

(See the Related section below for the asset_view API)

Example

[]

Properties

Michelson

Asset

contains

count

nth

sort

sum

select

head

tail

`big_map<K, V>`

Map from K-typed key to V-typed value, that can deal with a high number of keys.

The issue with a standard map is that the cost of deserialisation becomes prohibitive as the number of keys increases. Indeed a map, as well as any storage element, is stored in a serialised format, and gets deserialised each time the contract storage is accessed.

A big map is not stored in the contract storage, but rather has its own dedicated storage; it is referenced from the contract storage by an integer value, hence the deserialisation cost of the contract storage is not impacted by the number of keys in the big map.

info

The constraint is that a big map is not iterable (because only a hash of the key is stored, not the key itself). It means that the for instruction and the length builtin are not available for big maps. See the iterable_big_map type for an iterable big map.

Examples

[]

[ ("#1G1AF1F57A7192174", 5); ("#2F4AH1J77O7132095", 10) ]

Properties

Michelson

Map

[]

put

remove

update

put

remove

update

contains

map

make_big_map

iterable_big_map

`bls12_381_fr`

Multplicative scalar for the BLS12_381 curves g1 and g2.
Literals can either be a raw bytes representation or a natural.

Examples

0x2fr

-42fr

Properties

Michelson

Elliptic curves

bls12_381_g1

bls12_381_g2

pairing_check

`bls12_381_g1`

Point on the elliptic curve g1.

Example

0x063bd6e11e2fcaac1dd8cf68c6b1925a73c3c583e298ed37c41c3715115cf96358a42dbe85a0228cbfd8a6c8a8c54cd015b5ae2860d1cc47f84698d951f14d9448d03f04df2ca0ffe609a2067d6f1a892163a5e05e541279134cae52b1f23c6bg1

Properties

Michelson

Elliptic curves

bls12_381_fr

bls12_381_g2

pairing_check

`bls12_381_g2`

Point on the elliptic curve g2.

Example

0x10c6d5cdca84fc3c7f33061add256f48e0ab03a697832b338901898b650419eb6f334b28153fb73ad2ecd1cd2ac67053161e9f46cfbdaf7b1132a4654a55162850249650f9b873ac3113fa8c02ef1cd1df481480a4457f351d28f4da89d19fa405c3d77f686dc9a24d2681c9184bf2b091f62e6b24df651a3da8bd7067e14e7908fb02f8955b84af5081614cb5bc49b416d9edf914fc608c441b3f2eb8b6043736ddb9d4e4d62334a23b5625c14ef3e1a7e99258386310221b22d83a5eac035cg2

Properties

Michelson

Elliptic curves

bls12_381_fr

bls12_381_g1

pairing_check

`bool`

Boolean value true or false for logical tests.

Examples

true

false

Properties

Michelson

if

while

do_require

do_fail_if

remove_if

&=

|=

and

or

xor

not

=

<>

<=>

if

?:

check_signature

contains

greedy_and

greedy_or

is_none

is_some

open_chest

pairing_check

select

`bytes`

Array of byte values to represent any serialised data. It is used for signatures and hash values.

Examples

0x00

0x050002

0x

Properties

Michelson

concat

length

slice

pack

unpack

sha256

sha3

sha512

blake2b

keccak

bytes_to_nat

nat_to_bytes

int_to_bytes

check_signature

open_chest

`chain_id`

`C D`

Type of the chain network identifier.

Examples

"NetXdQprcVkpaWU"

chain_id

Properties

Michelson

chain_id

`chest`

Timelocked encrypted value. It is generated off-chain with the timelock-utils, and decrypted on-chain with the open_chest builtin.

Example

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

Properties

Michelson

Timelock

chest_key

open_chest

`chest_key`

Key used by open_chest builtin to decrypt a chest value. It is generated off-chain with the timelock-utils together with the chest value.

Example

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

Properties

Michelson

Timelock

chest

open_chest

`contract<T>`

Destination value of an operation; it represents either an account's address, a contract's address, or a contract entrypoint.
It is returned by the get_entrypoint builtin, or by the conversion builtins address_to_contract and key_hash_to_contract

Example

Properties

Michelson

Operation

address_to_contract

contract_to_address

get_entrypoint

key_hash_to_contract

make_operation

`date`

Date in ISO_8601 format.

Examples

2019-01-01

2019-01-01T01:02:03

2019-01-01T01:02:03Z

2019-01-01T00:00:00+01:00

2019-01-01T00:00:00-05:30

Properties

Michelson

now

+

-

=

<>

<

<=

>

>=

<=>

+=

-=

int_to_date

`duration`

Number of seconds expressed in seconds, minutes, hours or weeks, for operations on dates.

Examples

10s

5m

18h

3d

1w

5m10s

5d12h

3w8d4h34m18s

Properties

Michelson

+

-

=

<>

<

<=

>

>=

<=>

+=

-=

`enum`

`E F`

Union of several types: its value is one of the possible declared values; values can be parameterized.

Examples

enum color = | Red | Green | Blue

Red

Green

Blue

Properties

Michelson

Enum

match with

`event`

Type of event to be emitted, as explained in this blog entry.

Example

Property

Michelson

Event

emit

`I J`

`int`

Arbitrary-precision integer values (no arithmetic overflow).

Examples

0i

2i

123i

-1

100_000i

Properties

Michelson

nat

+

-

*

/

div

%

/%

=

<>

<

<=

>

>=

<=>

+=

-=

*=

/=

abs

ceil

floor

get_numerator

int_to_date

int_to_nat

`iterable_big_map<K, V>`

An iterable big map has the scalability property of a big_map and can be iterated.

Consider the following declaration:

variable m : iterable_big_map<nat, string> = []

It is then possible to iterate over m:

for (k,v) in m do
  /* k is the key */
  /* v is the value associated to k */
done

An iterable big map is compiled in Michelson as a triplet:

a big map for the keys
a big map for the values
a counter

The detailed mechanism is presented in this blog entry.

info

The order in which keys are iterated is not the natural order.

caution

The possiblity to iterate comes with an increased cost of put remove and update operations.

Examples

[]

[ ("#1G1AF1F57A7192174", 5); ("#2F4AH1J77O7132095", 10) ]

Properties

Michelson

Map

[]

put

remove

update

for

put

remove

update

contains

length

map

big_map

`K L`

`key`

Account's public key.

Example

"edpkurLzuFFL1XyP3fed4u7MsgeywQoQmHM45Bz91PBzDvUjQ9bvdn"

Properties

Michelson

check_signature

key_to_key_hash

key_to_address

`key_hash`

Hash of a public key.

Example

"tz1Lc2qBKEWCBeDU8npG6zCeCqpmaegRi6Jg"

Properties

Michelson

key_to_key_hash

key_hash_to_contract

sapling_empty_state

set_delegate

voting_power

`lambda<T, R>`

Anonymous function value with a parameter of type T that returns a value of type R.

Example

lambda<nat>((x : nat) -> 2 * x + 1)

Properties

Michelson

apply_lambda

exec_lambda

`list<T>`

Chained list of elements.

Parameter

T

(any type)

type of the elements of the list

Examples

[]

[ 1 ]

[ "abc", "def" ]

Properties

Michelson

List

prepend

reverse

concat

for

concat

contains

length

map

nth

pairing_check

prepend

reverse

make_list

`M N`

`map<K, V>`

Imutable (read only) maps from key to value; keys are sorted in natural order (K is comparable).

Parameters

K

(any comparable type)

type of the key

V

(any type)

type of the associated value

Example

[ (0, "a string"); (1, "another string") ]

Properties

Michelson

Map

[]

put

remove

update

for

put

remove

update

contains

length

map

make_map

big_map

iterable_big_map

`nat`

Arbitrary-precision natural values (no arithmetic overflow).

Examples

0

2

123

100_000

Properties

Michelson

`never`

Empty type.

For example, it is used to prevent from using specific value in or or option literals:

variable res : or<never, nat> = right<never>(1)

Example

Properties

Michelson

`operation`

Operation generated by contract execution.

Example

Property

Michelson

transfer

make_operation

event

`option<T>`

Optional value, that is either some value of type T, or none.

Parameter

T

(any type)

type of the value when the option is some value

Examples

none

some("abcd")

Properties

Michelson

match with

fail_some

update

call_view

get

get_entrypoint

get_some

int_to_nat

is_none

is_some

join_tickets

map

none

sapling_verify_update

set_delegate

slice

some

split_tockets

sub_mutez

unpack

update

match with

? :

[]

`or<T1, T2>`

Union of two types: its value can either be of the one or the other type (left or right).

Parameters

T1

(any type)

left type

T2

(any type)

right type

Examples

const o : or<nat, string> = left<string>(2)

const o : or<nat, string> = left<nat, string>(2)

const o : or<nat, string> = right<nat>("#a56fG")

const o : or<nat, string> = right<nat, string>("#a56fG")

Properties

Michelson

match with

fold

left

open_chest

right

`partition<A>`

Type of asset field to reference assets from another collection A, so that each asset from A is referenced by exactly one asset from this collection.

For example, field drives references assets from the car asset collection:

asset car {
  vin     : string;
  nbdoors : nat = 0
}

asset driver {
  id     : address;
  drives : partition<car>
}

Notes:

a car asset may only be added via the drives partition with for example:

driver[a].drives.add({ vin : "1G1AF1F57A7192174" })

straightforwardly adding in car collection fails at compilation
two drivers cannot reference the same car

Example

Properties

Michelson

Asset

aggregate

asset_view

`Q R`

`rational`

Arbitrary-precision floating point number.

It is implemented in Michelson as a pair of int and nat.

Examples

1.1

-1.1

1 / 3

-1 / 3

80%

4.2%

Properties

Michelson

+

-

*

/

=

<>

<

<=

>

>=

<=>

+=

-=

*=

/=

abs

ceil

floor

simplify_rational

get_numerator

get_denominator

`record`

Fixed list of named fields of different types.

A record has the common properties of its fields.

Example

{ red = 0xa4; green = 0x6a; blue = 0xc0 }

Property

Michelson

Record

:=

+=

-=

*=

/=

&=

|=

{ with }

.

`S T`

`sapling_state(n)`

Sapling state.

Parameter

n

(natural number)

Memo size

Example

Properties

Michelson

Sapling

sapling_empty_state

sapling_verify_update

`sapling_transaction(n)`

Sapling transaction.

Parameter

n

(natural number)

Memo size

Example

Properties

Michelson

Sapling

sapling_empty_state

sapling_verify_update

`set<T>`

Set of values of comparable type T. It can be iterated with for in T's natural order.

Example

[ tz1VSUr8wwNhLAzempoch5d6hLRiTh8Cjcjb; tz1aSkwEot3L2kmUvcoxzjMomb9mvBNuzFK6]

Properties

Michelson

Set

for

add

remove

add

contains

length

remove

make_set

`signature`

Cryptographic signature.

Example

"edsigtvwtJaiM7phNNkZjazqKtthDxc3WswYNL961GKgz7VxvPJmWJ8WEkmEZd9oFM1RvwABYW3uYgwGRP7nuBns5WrqyfYsUaB"

Properties

Michelson

Signature

check_signature

`string`

Array of non-extended ASCII characters.

Examples

"This is a string"

"12345"

Properties

Michelson

+

concat

length

nat_to_string

slice

call_view

get_entrypoint

`tez`

Tezos currency in mutez (millionth of XTZ); several literal units are provided:

1tz is 1000000 mutez
1mtz is 1000 mutez
1utz is 1 mutez

For tz and mtz it is possible to use floating point literals with a maximum of respectively 6 and 3 decimal places; hence 1.5324235tz and 1.5324mtz are not valid.

Examples

1tz

1mtz

1utz

1.23tz

1.2mtz

Properties

Michelson

+

-

*

/

div

%

=

<>

<

<=

>

>=

<=>

+=

mutez_to_nat

sub_mutez

make_operation

`ticket<T>`

Contract-authenticated data.

Parameter

T

(any type)

type of the value held by the ticket

Example

Properties