Sophia language offers standard library that consists of several namespaces. Some of them are already in the scope and do not need any actions to be used, while the others require some files to be included.
The out-of-the-box namespaces are:
The following ones need to be included as regular files with .aes
suffix, for example
include "List.aes"
They are available without any explicit includes.
Address.to_str(a : address) : string
Base58 encoded string
Address.to_bytes(a : address) : bytes(32)
The binary representation of the address.
Address.is_contract(a : address) : bool
Is the address a contract
Address.is_oracle(a : address) : bool
Is the address a registered oracle
Address.is_payable(a : address) : bool
Can the address be spent to
Address.to_contract(a : address) : C
Cast address to contract type C (where C
is a contract)
The old AENS namespace, kept in the compiler to be able to interact with contracts from before Ceres, compiled using aesophia compiler version 7.x and earlier. Used in AENSCompat when converting between old and new pointers.
datatype name = Name(address, Chain.ttl, map(string, AENS.pointee))
datatype pointee = AccountPt(address) | OraclePt(address)
| ContractPt(address) | ChannelPt(address)
Note: introduced in v8.0
The following functionality is available for interacting with the æternity
naming system (AENS). If owner
is equal to Contract.address
the signature
signature
is ignored, and can be left out since it is a named argument.
Otherwise we need a signature to prove that we are allowed to do AENS
operations on behalf of owner
. The signature is tied to a network
id,
i.e. the signature material should be prefixed by the network id.
datatype name = Name(address, Chain.ttl, map(string, AENSv2.pointee))
datatype pointee = AccountPt(address) | OraclePt(address)
| ContractPt(address) | ChannelPt(address) | DataPt(bytes())
Note: on-chain there is a maximum length enforced for DataPt
, it is 1024 bytes.
Sophia itself does not check for this.
AENSv2.resolve(name : string, key : string) : option('a)
Name resolution. Here name
should be a registered name and key
one of the attributes
associated with this name (for instance "account_pubkey"
). The return type
('a
) must be resolved at compile time to an atomic type and the value is
type checked against this type at run time.
AENSv2.lookup(name : string) : option(AENSv2.name)
If name
is an active name AENSv2.lookup
returns a name object.
The three arguments to Name
are owner
, expiry
and a map of the
pointees
for the name. Note: the expiry of the name is always a fixed TTL.
For example:
let Some(AENSv2.Name(owner, FixedTTL(expiry), ptrs)) = AENSv2.lookup("example.chain")
Note: Changed to produce AENSv2.name
in v8.0 (Ceres protocol upgrade).
AENSv2.preclaim(owner : address, commitment_hash : hash, <signature : signature>) : unit
The signature should be a
serialized structure containing network id
, owner address
, and
Contract.address
.
From Ceres (i.e. FATE VM version 3) the
signature can also be generic
(allowing all, existing and future, names to be delegated with one
signature), i.e. containing network id
, owner address
, Contract.address
.
AENSv2.claim(owner : address, name : string, salt : int, name_fee : int, <signature : signature>) : unit
The signature should be a
serialized structure containing network id
, owner address
, and
Contract.address
. Using the private key of owner address
for signing.
From Ceres (i.e. FATE VM version 3) the
signature can also be generic
(allowing all, existing and future, names to be delegated with one
signature), i.e. containing network id
, owner address
, name_hash
, and
Contract.address
.
AENSv2.transfer(owner : address, new_owner : address, name : string, <signature : signature>) : unit
Transfers name to the new owner.
The signature should be a
serialized structure containing network id
, owner address
, and
Contract.address
. Using the private key of owner address
for signing.
From Ceres (i.e. FATE VM version 3) the
signature can also be generic
(allowing all, existing and future, names to be delegated with one
signature), i.e. containing network id
, owner address
, name_hash
, and
Contract.address
.
AENSv2.revoke(owner : address, name : string, <signature : signature>) : unit
Revokes the name to extend the ownership time.
The signature should be a
serialized structure containing network id
, owner address
, and
Contract.address
. Using the private key of owner address
for signing.
From Ceres (i.e. FATE VM version 3) the
signature can also be generic
(allowing all, existing and future, names to be delegated with one
signature), i.e. containing network id
, owner address
, name_hash
, and
Contract.address
.
AENSv2.update(owner : address, name : string, expiry : option(Chain.ttl), client_ttl : option(int),
new_ptrs : option(map(string, AENSv2.pointee)), <signature : signature>) : unit
Updates the name. If the optional parameters are set to None
that parameter
will not be updated, for example if None
is passed as expiry
the expiry
block of the name is not changed.
Note: Changed to consume AENSv2.pointee
in v8.0 (Ceres protocol upgrade).
The signature should be a
serialized structure containing network id
, owner address
, and
Contract.address
. Using the private key of owner address
for signing.
From Ceres (i.e. FATE VM version 3) the
signature can also be generic
(allowing all, existing and future, names to be delegated with one
signature), i.e. containing network id
, owner address
, name_hash
, and
Contract.address
.
Auth.tx : option(Chain.tx)
Where Chain.tx
is (built-in) defined like:
namespace Chain =
record tx = { paying_for : option(Chain.paying_for_tx)
, ga_metas : list(Chain.ga_meta_tx)
, actor : address
, fee : int
, ttl : int
, tx : Chain.base_tx }
datatype ga_meta_tx = GAMetaTx(address, int)
datatype paying_for_tx = PayingForTx(address, int)
datatype base_tx = SpendTx(address, int, string)
| OracleRegisterTx | OracleQueryTx | OracleResponseTx | OracleExtendTx
| NamePreclaimTx | NameClaimTx(hash) | NameUpdateTx(string)
| NameRevokeTx(hash) | NameTransferTx(address, string)
| ChannelCreateTx(address) | ChannelDepositTx(address, int) | ChannelWithdrawTx(address, int) |
| ChannelForceProgressTx(address) | ChannelCloseMutualTx(address) | ChannelCloseSoloTx(address)
| ChannelSlashTx(address) | ChannelSettleTx(address) | ChannelSnapshotSoloTx(address)
| ContractCreateTx(int) | ContractCallTx(address, int)
| GAAttachTx
Auth.tx_hash : option(hash)
Gets the transaction hash during authentication. Note: Auth.tx_hash
computation differs between protocol versions (changed in Ceres!), see
aeserialisation
specification for details.
Bits.none : bits
A bit field with all bits cleared
Bits.all : bits
A bit field with all bits set
Bits.set(b : bits, i : int) : bits
Set bit i
Bits.clear(b : bits, i : int) : bits
Clear bit i
Bits.test(b : bits, i : int) : bool
Check if bit i is set
Bits.sum(b : bits) : int
Count the number of set bits
Bits.union(a : bits, b : bits) : bits
Bitwise disjunction
Bits.intersection(a : bits, b : bits) : bits
Bitwise conjunction
Bits.difference(a : bits, b : bits) : bits
Each bit is true if and only if it was 1 in a
and 0 in b
Bytes.to_int(b : bytes(n)) : int
Interprets the byte array as a big endian integer
Bytes.to_str(b : bytes(n)) : string
Returns the hexadecimal representation of the byte array
Bytes.concat : (a : bytes(m), b : bytes(n)) => bytes(m + n)
Concatenates two byte arrays. If m
and n
are known at compile time, the
result can be used as a fixed size byte array, otherwise it has type bytes()
.
Bytes.split(a : bytes(m + n)) : bytes(m) * bytes(n)
Splits a byte array at given index
Bytes.split_any(a : bytes(), at : int) : option(bytes() * bytes(n))
Splits an arbitrary size byte array at index at
. If at
is positive split
from the beginning of the array, if at
is negative, split abs(at)
from the
end of the array. If the array is shorter than abs(at)
then None
is
returned.
Bytes.to_fixed_size(a : bytes()) : option(bytes(n))
Converts an arbitrary size byte array to a fix size byte array. If a
is
not n
bytes, None
is returned.
Bytes.to_any_size(a : bytes(n)) : bytes()
Converts a fixed size byte array to an arbitrary size byte array. This is a no-op at run-time, and only used during type checking.
Bytes.size(a : bytes()) : int
Computes the lenght/size of a byte array.
Values related to the call to the current contract
Call.origin : address
The address of the account that signed the call transaction that led to this call.
Call.caller : address
The address of the entity (possibly another contract) calling the contract.
Call.value : int
The amount of coins transferred to the contract in the call.
Call.gas_price : int
The gas price of the current call.
Int.mulmod : (a : int, b : int, q : int) : int
Combined multiplication and modulus, returns (a * b) mod q
.
Call.fee : int
The fee of the current call.
Call.gas_left() : int
The amount of gas left for the current call.
Values and functions related to the chain itself and other entities that live on it.
record tx = { paying_for : option(Chain.paying_for_tx)
, ga_metas : list(Chain.ga_meta_tx)
, actor : address
, fee : int
, ttl : int
, tx : Chain.base_tx }
datatype ga_meta_tx = GAMetaTx(address, int)
datatype paying_for_tx = PayingForTx(address, int)
datatype base_tx = SpendTx(address, int, string)
| OracleRegisterTx | OracleQueryTx | OracleResponseTx | OracleExtendTx
| NamePreclaimTx | NameClaimTx(hash) | NameUpdateTx(string)
| NameRevokeTx(hash) | NameTransferTx(address, string)
| ChannelCreateTx(address) | ChannelDepositTx(address, int) | ChannelWithdrawTx(address, int) |
| ChannelForceProgressTx(address) | ChannelCloseMutualTx(address) | ChannelCloseSoloTx(address)
| ChannelSlashTx(address) | ChannelSettleTx(address) | ChannelSnapshotSoloTx(address)
| ContractCreateTx(int) | ContractCallTx(address, int)
| GAAttachTx
Chain.balance(a : address) : int
The balance of account a
.
Chain.block_hash(h : int) : option(bytes(32))
The hash of the block at height h
. h
has to be within 256 blocks from the
current height of the chain or else the function will return None
.
NOTE: In FATE VM version 1 Chain.block_height
was not considered an
allowed height. From FATE VM version 2 (IRIS) it will return the block hash of
the current generation.
Chain.block_height : int"
The height of the current block (i.e. the block in which the current call will be included).
Chain.bytecode_hash : 'c => option(hash)
Returns the hash of the contract's bytecode (or None
if it is
nonexistent or deployed before FATE2). The type 'c
must be
instantiated with a contract. The charged gas increases linearly to
the size of the serialized bytecode of the deployed contract.
Chain.create(value : int, ...) => 'c
Creates and deploys a new instance of a contract 'c
. All of the
unnamed arguments will be passed to the init
function. The charged
gas increases linearly with the size of the compiled child contract's
bytecode. The source_hash
on-chain entry of the newly created
contract will be the SHA256 hash over concatenation of
- whole contract source code
- single null byte
- name of the child contract
The resulting contract's public key can be predicted and in case it happens to
have some funds before its creation, its balance will be increased by
the value
parameter.
The value
argument (default 0
) is equivalent to the value in the contract
creation transaction – it sets the initial value of the newly created contract
charging the calling contract. Note that this won't be visible in Call.value
in the init
call of the new contract. It will be included in
Contract.balance
, however.
The type 'c
must be instantiated with a contract.
Example usage:
payable contract Auction =
record state = {supply: int, name: string}
entrypoint init(supply, name) = {supply: supply, name: name}
stateful payable entrypoint buy(amount) =
require(Call.value == amount, "amount_value_mismatch")
...
stateful entrypoint sell(amount) =
require(amount >= 0, "negative_amount")
...
main contract Market =
type state = list(Auction)
entrypoint init() = []
stateful entrypoint new(name : string) =
let new_auction = Chain.create(0, name) : Auction
put(new_auction::state)
The typechecker must be certain about the created contract's type, so it is worth writing it explicitly as shown in the example.
Chain.clone : ( ref : 'c, gas : int, value : int, protected : bool, ...
) => if(protected) option('c) else 'c
Clones the contract under the mandatory named argument ref
. That means a new
contract of the same bytecode and the same payable
parameter shall be created.
NOTE: the state
won't be copied and the contract will be initialized with
a regular call to the init
function with the remaining unnamed arguments. The
resulting contract's public key can be predicted and in case it happens to have
some funds before its creation, its balance will be increased by the value
parameter. This operation is significantly cheaper than Chain.create
as it
costs a fixed amount of gas.
The gas
argument (default Call.gas_left
) limits the gas supply for the
init
call of the cloned contract.
The value
argument (default 0
) is equivalent to the value in the contract
creation transaction – it sets the initial value of the newly created contract
charging the calling contract. Note that this won't be visible in Call.value
in the init
call of the new contract. It will be included in
Contract.balance
, however.
The protected
argument (default false
) works identically as in remote calls.
If set to true
it will change the return type to option('c)
and will catch
all errors such as abort
, out of gas and wrong arguments. Note that it can
only take a boolean literal, so other expressions such as variables will be
rejected by the compiler.
The type 'c
must be instantiated with a contract.
Example usage:
payable contract interface Auction =
entrypoint init : (int, string) => void
stateful payable entrypoint buy : (int) => unit
stateful entrypoint sell : (int) => unit
main contract Market =
type state = list(Auction)
entrypoint init() = []
stateful entrypoint new_of(template : Auction, name : string) =
switch(Chain.clone(ref=template, protected=true, 0, name))
None => abort("Bad auction!")
Some(new_auction) =>
put(new_auction::state)
When cloning by an interface, init
entrypoint declaration is required. It is a
good practice to set its return type to void
in order to indicate that this
function is not supposed to be called and is state agnostic. Trivia: internal
implementation of the init
function does not actually return state
, but
calls put
instead. Moreover, FATE prevents even handcrafted calls to init
.
Chain.coinbase : address
The address of the account that mined the current block.
Chain.difficulty : int
The difficulty of the current block.
Chain.event(e : event) : unit
Emits the event. To use this function one needs to define the event
type as a
datatype
in the contract.
Chain.gas_limit : int
The gas limit of the current block.
Chain.network\_id : string
The network id of the chain.
Crypto.poseidon(x1 : int, x2 : int) : int
Hash two integers (in the scalar field of BLS12-381) to another integer (in the scalar field of BLS12-281). This is a ZK/SNARK-friendly hash function.
Chain.spend(to : address, amount : int) : unit
Spend amount
tokens to to
. Will fail (and abort the contract) if contract
doesn't have amount
tokens to transfer, or, if to
is not payable
.
Chain.timestamp : int
The timestamp of the current block (unix time, milliseconds).
Char.to_int(c : char) : int
Returns the UTF-8 codepoint of a character
Char.from_int(i : int) : option(char)
Opposite of to_int. Returns None
if the integer doesn't correspond to a single (normalized) codepoint.
Values related to the current contract
Contract.creator : address
Address of the entity that signed the contract creation transaction
Contract.address : address
Address of the contract account
Contract.balance : int
Amount of coins in the contract account
Crypto.sha3(x : 'a) : hash
Hash any object to SHA3
Crypto.sha256(x : 'a) : hash
Hash any object to SHA256
Crypto.blake2b(x : 'a) : hash
Hash any object to blake2b
Crypto.verify_sig(msg : bytes(), pubkey : address, sig : signature) : bool
Checks if the signature of msg
was made using private key corresponding to
the pubkey
.
Note: before v8 of the compiler, msg
had type hash
(i.e. bytes(32)
).
Crypto.ecverify_secp256k1(msg : hash, addr : bytes(20), sig : bytes(65)) : bool
Verifies a signature for a msg against an Ethereum style address. Note that the
signature should be 65 bytes and include the recovery identifier byte V
. The
expected organization of the signature is (V || R || S
).
Crypto.ecrecover_secp256k1(msg : hash, sig : bytes(65)) : option(bytes(20))
Recovers the Ethereum style address from a msg hash and respective
ECDSA-signature. Note that the signature should be 65 bytes and include the
recovery identifier byte V
. The expected organization of the signature is (V || R || S
).
Crypto.verify_sig_secp256k1(msg : hash, pubkey : bytes(64), sig : bytes(64)) : bool
Verifies a standard 64-byte ECDSA signature (R || S
).
Int.to_str(n : int) : string
Casts the integer to a string (in decimal representation).
Int.to_bytes(n : int, size : int) : bytes()
Casts the integer to a byte array with size
bytes (big endian, truncating if
necessary not preserving signedness). I.e. if you try to squeeze -129
into a
single byte that will be indistinguishable from 127
.
Map.lookup(k : 'k, m : map('k, 'v)) : option('v)
Returns the value under a key in given map as Some
or None
if the key is not present
Map.lookup_default(k : 'k, m : map('k, 'v), v : 'v) : 'v
Returns the value under a key in given map or the
default value v
if the key is not present
Map.member(k : 'k, m : map('k, 'v)) : bool
Checks if the key is present in the map
Map.delete(k : 'k, m : map('k, 'v)) : map('k, 'v)
Removes the key from the map
Map.size(m : map('k, 'v)) : int
Returns the number of elements in the map
Map.to_list(m : map('k, 'v)) : list('k * 'v)
Returns a list containing pairs of keys and their respective elements.
Map.from_list(m : list('k * 'v)) : map('k, 'v)
Turns a list of pairs of form (key, value)
into a map
Oracle.register(<signature : bytes(64)>, acct : address, qfee : int, ttl : Chain.ttl) : oracle('a, 'b)
Registers new oracle answering questions of type 'a
with answers of type 'b
.
- The
acct
is the address of the oracle to register (can be the same as the contract). - The signature should be a
serialized structure containing
network id
,account address
, andcontract address
. Using the private key ofaccount address
for signing. Proving you have the private key of the oracle to be. If the address is the same as the contractsign
is ignored and can be left out entirely. - The
qfee
is the minimum query fee to be paid by a user when asking a question of the oracle. - The
ttl
is the Time To Live for the oracle in key blocks, either relative to the current key block height (RelativeTTL(delta)
) or a fixed key block height (FixedTTL(height)
). - The type
'a
is the type of the question to ask. - The type
'b
is the type of the oracle answers.
Examples:
Oracle.register(addr0, 25, RelativeTTL(400))
Oracle.register(addr1, 25, RelativeTTL(500), signature = sign1)
Oracle.get_question(o : oracle('a, 'b), q : oracle_query('a, 'b)) : 'a
Checks what was the question of query q
on oracle o
Oracle.respond(<signature : bytes(64)>, o : oracle('a, 'b), q : oracle_query('a, 'b), 'b) : unit
Responds to the question q
on o
. Unless the contract address is the same
as the oracle address the signature
(which is an optional, named argument)
needs to be provided. Proving that we have the private key of the oracle by
signing should be a serialized
structure containing network id
, oracle query id
, and contract address
.
Oracle.extend(<signature : bytes(64)>, o : oracle('a, 'b), ttl : Chain.ttl) : unit
Extends TTL of an oracle.
singature
is a named argument and thus optional. Must be the same as forOracle.register
o
is the oracle being extendedttl
must beRelativeTTL
. The time to live ofo
will be extended by this value.
Oracle.query_fee(o : oracle('a, 'b)) : int
Returns the query fee of the oracle
Oracle.query(o : oracle('a, 'b), q : 'a, qfee : int, qttl : Chain.ttl, rttl : Chain.ttl) : oracle_query('a, 'b)
Asks the oracle a question.
- The
qfee
is the query fee debited to the contract account (Contract.address
). - The
qttl
controls the last height at which the oracle can submit a response and can be either fixed or relative. - The
rttl
must be relative and controls how long an answer is kept on the chain. The call fails if the oracle could expire before an answer.
Oracle.get_answer(o : oracle('a, 'b), q : oracle_query('a, 'b)) : option('b)
Checks what is the optional query answer
Oracle.expiry(o : oracle('a, 'b)) : int
Ask the oracle when it expires. The result is the block height at which it will happen.
Oracle.check(o : oracle('a, 'b)) : bool
Returns true
iff the oracle o
exists and has correct type
Oracle.check_query(o : oracle('a, 'b), q : oracle_query('a, 'b)) : bool
It returns true
iff the oracle query exist and has the expected type.
These need to be explicitly included (with .aes
suffix)
AENSCompat.pointee_to_V2(p : AENS.pointee) : AENSv2.pointee
Translate old pointee format to new, this is always possible.
AENSCompat.pointee_from_V2(p2 : AENSv2.pointee) : option(AENS.pointee)
Translate new pointee format to old, DataPt
can't be translated, so None
is returned in this case.
Built-in (Montgomery) integer representation 32 bytes
Built-in (Montgomery) integer representation 48 bytes
record fp2 = { x1 : fp, x2 : fp }`
record g1 = { x : fp, y : fp, z : fp }
record g2 = { x : fp2, y : fp2, z : fp2 }
record gt = { x1 : fp, x2 : fp, x3 : fp, x4 : fp, x5 : fp, x6 : fp, x7 : fp, x8 : fp, x9 : fp, x10 : fp, x11 : fp, x12 : fp }
BLS12_381.pairing_check(xs : list(g1), ys : list(g2)) : bool
Pairing check of a list of points, xs
and ys
should be of equal length.
BLS12_381.int_to_fr(x : int) : fr
Convert an integer to an fr
- a 32 bytes internal (Montgomery) integer representation.
BLS12_381.int_to_fp(x : int) : fp
Convert an integer to an fp
- a 48 bytes internal (Montgomery) integer representation.
BLS12_381.fr_to_int(x : fr) : int
Convert a fr
value into an integer.
BLS12_381.fp_to_int(x : fp) : int
Convert a fp
value into an integer.
BLS12_381.mk_g1(x : int, y : int, z : int) : g1
Construct a g1
point from three integers.
BLS12_381.mk_g2(x1 : int, x2 : int, y1 : int, y2 : int, z1 : int, z2 : int) : g2
Construct a g2
point from six integers.
BLS12_381.g1_neg(p : g1) : g1
Negate a g1
value.
BLS12_381.g1_norm(p : g1) : g1
Normalize a g1
value.
BLS12_381.g1_valid(p : g1) : bool
Check that a g1
value is a group member.
BLS12_381.g1_is_zero(p : g1) : bool
Check if a g1
value corresponds to the zero value of the group.
BLS12_381.g1_add(p : g1, q : g1) : g1
Add two g1
values.
BLS12_381.g1_mul(k : fr, p : g1) : g1
Scalar multiplication for g1
.
BLS12_381.g2_neg(p : g2) : g2
Negate a g2
value.
BLS12_381.g2_norm(p : g2) : g2
Normalize a g2
value.
BLS12_381.g2_valid(p : g2) : bool
Check that a g2
value is a group member.
BLS12_381.g2_is_zero(p : g2) : bool
Check if a g2
value corresponds to the zero value of the group.
BLS12_381.g2_add(p : g2, q : g2) : g2
Add two g2
values.
BLS12_381.g2_mul(k : fr, p : g2) : g2
Scalar multiplication for g2
.
BLS12_381.gt_inv(p : gt) : gt
Invert a gt
value.
BLS12_381.gt_add(p : gt, q : gt) : gt
Add two gt
values.
BLS12_381.gt_mul(p : gt, q : gt) : gt
Multiply two gt
values.
BLS12_381.gt_pow(p : gt, k : fr) : gt
Calculate exponentiation p ^ k
.
BLS12_381.gt_is_one(p : gt) : bool
Compare a gt
value to the unit value of the Gt group.
BLS12_381.pairing(p : g1, q : g2) : gt
Compute the pairing of a g1
value and a g2
value.
BLS12_381.miller_loop(p : g1, q : g2) : gt
Do the Miller loop stage of pairing for g1
and g2
.
BLS12_381.final_exp(p : gt) : gt
Perform the final exponentiation step of pairing for a gt
value.
Functional combinators.
Func.id(x : 'a) : 'a
Identity function. Returns its argument.
Func.const(x : 'a) : 'b => 'a = (y) => x
Constant function constructor. Given x
returns a function that returns x
regardless of its argument.
Func.flip(f : ('a, 'b) => 'c) : ('b, 'a) => 'c
Switches order of arguments of arity 2 function.
Func.comp(f : 'b => 'c, g : 'a => 'b) : 'a => 'c
Function composition. comp(f, g)(x) == f(g(x))
.
Func.pipe(f : 'a => 'b, g : 'b => 'c) : 'a => 'c
Flipped function composition. pipe(f, g)(x) == g(f(x))
.
Func.rapply(x : 'a, f : 'a => 'b) : 'b
Reverse application. rapply(x, f) == f(x)
.
Func.recur(f : ('arg => 'res, 'arg) => 'res) : 'arg => 'res
The Z combinator. Allows performing local recursion and having anonymous recursive lambdas. To make function A => B
recursive the user needs to transform it to take two arguments instead – one of type A => B
which is going to work as a self-reference, and the other one of type A
which is the original argument. Therefore, transformed function should have (A => B, A) => B
signature.
Example usage:
let factorial = recur((fac, n) => if(n < 2) 1 else n * fac(n - 1))
If the function is going to take more than one argument it will need to be either tuplified or have curried out latter arguments.
Example (factorial with custom step):
// tuplified version
let factorial_t(n, step) =
let fac(rec, args) =
let (n, step) = args
if(n < 2) 1 else n * rec((n - step, step))
recur(fac)((n, step))
// curried version
let factorial_c(n, step) =
let fac(rec, n) = (step) =>
if(n < 2) 1 else n * rec(n - 1)(step)
recur(fac)(n)(step)
Func.iter(n : int, f : 'a => 'a) : 'a => 'a
n
th composition of f with itself, for instance iter(3, f)
is equivalent to (x) => f(f(f(x)))
.
Func.curry2(f : ('a, 'b) => 'c) : 'a => ('b => 'c)
Func.curry3(f : ('a, 'b, 'c) => 'd) : 'a => ('b => ('c => 'd))
Turns a function that takes n arguments into a curried function that takes
one argument and returns a function that waits for the rest in the same
manner. For instance curry2((a, b) => a + b)(1)(2) == 3
.
Func.uncurry2(f : 'a => ('b => 'c)) : ('a, 'b) => 'c
Func.uncurry3(f : 'a => ('b => ('c => 'd))) : ('a, 'b, 'c) => 'd
Opposite to curry.
Func.tuplify2(f : ('a, 'b) => 'c) : (('a * 'b)) => 'c
Func.tuplify3(f : ('a, 'b, 'c) => 'd) : 'a * 'b * 'c => 'd
Turns a function that takes n arguments into a function that takes an n-tuple.
Func.untuplify2(f : 'a * 'b => 'c) : ('a, 'b) => 'c
Func.untuplify3(f : 'a * 'b * 'c => 'd) : ('a, 'b, 'c) => 'd
Opposite to tuplify.
This namespace provides operations on rational numbers. A rational number is represented
as a fraction of two integers which are stored internally in the frac
datatype.
The datatype consists of three constructors Neg/2
, Zero/0
and Pos/2
which determine the
sign of the number. Both values stored in Neg
and Pos
need to be strictly positive
integers. However, when creating a frac
you should never use the constructors explicitly.
Instead of that, always use provided functions like make_frac
or from_int
. This helps
keeping the internal representation well defined.
The described below functions take care of the normalization of the fractions –
they won't grow if it is unnecessary. Please note that the size of frac
can be still
very big while the value is actually very close to a natural number – the division of
two extremely big prime numbers will be as big as both of them. To face this issue
the optimize function is provided. It will approximate the value of the
fraction to fit in the given error margin and to shrink its size as much as possible.
Important note: frac
must not be compared using standard <
-like operators.
The operator comparison is not possible to overload at this moment, nor the
language provides checkers to prevent unintended usage of them. Therefore the typechecker
will allow that and the results of such comparison will be unspecified.
You should use lt, geq, eq etc instead.
datatype frac = Pos(int, int) | Zero | Neg(int, int)
Internal representation of fractional numbers. First integer encodes the numerator and the second the denominator – both must be always positive, as the sign is being handled by the choice of the constructor.
Frac.make_frac(n : int, d : int) : frac
Creates a fraction out of numerator and denominator. Automatically normalizes, so
make_frac(2, 4)
and make_frac(1, 2)
will yield same results.
Frac.num(f : frac) : int
Returns the numerator of a fraction.
Frac.den(f : frac) : int
Returns the denominator of a fraction.
Frac.to_pair(f : frac) : int * int
Turns a fraction into a pair of numerator and denominator.
Frac.sign(f : frac) : int
Returns the signum of a fraction, -1, 0, 1 if negative, zero, positive respectively.
Frac.to_str(f : frac) : string
Conversion to string. Does not display division by 1 or denominator if equals zero.
Frac.simplify(f : frac) : frac
Reduces fraction to normal form if for some reason it is not in it.
Frac.eq(a : frac, b : frac) : bool
Checks if a
is equal to b
.
Frac.neq(a : frac, b : frac) : bool
Checks if a
is not equal to b
.
Frac.geq(a : frac, b : frac) : bool
Checks if a
is greater or equal to b
.
Frac.leq(a : frac, b : frac) : bool
Checks if a
is lesser or equal to b
.
Frac.gt(a : frac, b : frac) : bool
Checks if a
is greater than b
.
Frac.lt(a : frac, b : frac) : bool
Checks if a
is lesser than b
.
Frac.min(a : frac, b : frac) : frac
Chooses lesser of the two fractions.
Frac.max(a : frac, b : frac) : frac
Chooses greater of the two fractions.
Frac.abs(f : frac) : frac
Absolute value.
Frac.from_int(n : int) : frac
From integer conversion. Effectively make_frac(n, 1)
.
Frac.floor(f : frac) : int
Rounds a fraction to the nearest lesser or equal integer.
Frac.ceil(f : frac) : int
Rounds a fraction to the nearest greater or equal integer.
Frac.round_to_zero(f : frac) : int
Rounds a fraction towards zero.
Effectively ceil
if lesser than zero and floor
if greater.
Frac.round_from_zero(f : frac) : int
Rounds a fraction from zero.
Effectively ceil
if greater than zero and floor
if lesser.
Frac.round(f : frac) : int
Rounds a fraction to a nearest integer. If two integers are in the same distance it will choose the even one.
Frac.add(a : frac, b : frac) : frac
Sum of the fractions.
Frac.neg(a : frac) : frac
Negation of the fraction.
Frac.sub(a : frac, b : frac) : frac
Subtraction of two fractions.
Frac.inv(a : frac) : frac
Inverts a fraction. Throws error if a
is zero.
Frac.mul(a : frac, b : frac) : frac
Multiplication of two fractions.
Frac.div(a : frac, b : frac) : frac
Division of two fractions.
Frac.int_exp(b : frac, e : int) : frac
Takes b
to the power of e
. The exponent can be a negative value.
Frac.optimize(f : frac, loss : frac) : frac
Shrink the internal size of a fraction as much as possible by approximating it to the
point where the error would exceed the loss
value.
Frac.is_sane(f : frac) : bool
For debugging. If it ever returns false in a code that doesn't call frac
constructors or
accept arbitrary frac
s from the surface you should report it as a
bug
If you expect getting calls with malformed frac
s in your contract, you should use
this function to verify the input.
This module contains common operations on lists like constructing, querying, traversing etc.
List.is_empty(l : list('a)) : bool
Returns true
iff the list is equal to []
.
List.first(l : list('a)) : option('a)
Returns Some
of the first element of a list or None
if the list is empty.
List.tail(l : list('a)) : option(list('a))
Returns Some
of a list without its first element or None
if the list is empty.
List.last(l : list('a)) : option('a)
Returns Some
of the last element of a list or None
if the list is empty.
List.contains(e : 'a, l : list('a)) : bool
Checks if list l
contains element e
. Equivalent to List.find(x => x == e, l) != None
.
List.find(p : 'a => bool, l : list('a)) : option('a)
Finds first element of l
fulfilling predicate p
as Some
or None
if no such element exists.
List.find_indices(p : 'a => bool, l : list('a)) : list(int)
Returns list of all indices of elements from l
that fulfill the predicate p
.
List.nth(n : int, l : list('a)) : option('a)
Gets n
th element of l
as Some
or None
if l
is shorter than n + 1
or n
is negative.
List.get(n : int, l : list('a)) : 'a
Gets n
th element of l
forcefully, throwing and error if l
is shorter than n + 1
or n
is negative.
List.length(l : list('a)) : int
Returns length of a list.
List.from_to(a : int, b : int) : list(int)
Creates an ascending sequence of all integer numbers between a
and b
(including a
and b
).
List.from_to_step(a : int, b : int, step : int) : list(int)
Creates an ascending sequence of integer numbers betweeen a
and b
jumping by given step
. Includes a
and takes b
only if (b - a) mod step == 0
. step
should be bigger than 0.
List.replace_at(n : int, e : 'a, l : list('a)) : list('a)
Replaces n
th element of l
with e
. Throws an error if n
is negative or would cause an overflow.
List.insert_at(n : int, e : 'a, l : list('a)) : list('a)
Inserts e
into l
to be on position n
by shifting following elements further. For instance,
insert_at(2, 9, [1,2,3,4])
will yield [1,2,9,3,4]
.
List.insert_by(cmp : (('a, 'a) => bool), x : 'a, l : list('a)) : list('a)
Assuming that cmp represents <
comparison, inserts x
before the first element in the list l
which is greater than it. For instance,
insert_by((a, b) => a < b, 4, [1,2,3,5,6,7])
will yield [1,2,3,4,5,6,7]
List.foldr(cons : ('a, 'b) => 'b, nil : 'b, l : list('a)) : 'b
Right fold of a list. Assuming l = [x, y, z]
will return f(x, f(y, f(z, nil)))
.
Not tail recursive.
List.foldl(rcons : ('b, 'a) => 'b, acc : 'b, l : list('a)) : 'b
Left fold of a list. Assuming l = [x, y, z]
will return f(f(f(acc, x), y), z)
.
Tail recursive.
List.foreach(l : list('a), f : 'a => unit) : unit
Evaluates f
on each element of a list.
List.reverse(l : list('a)) : list('a)
Returns a copy of l
with reversed order of elements.
List.map(f : 'a => 'b, l : list('a)) : list('b)
Maps function f
over a list. For instance
map((x) => x == 0, [1, 2, 0, 3, 0])
will yield [false, false, true, false, true]
List.flat_map(f : 'a => list('b), l : list('a)) : list('b)
Maps f
over a list and then flattens it. For instance
flat_map((x) => [x, x * 10], [1, 2, 3])
will yield [1, 10, 2, 20, 3, 30]
List.filter(p : 'a => bool, l : list('a)) : list('a)
Filters out elements of l
that fulfill predicate p
. For instance
filter((x) => x > 0, [-1, 1, -2, 0, 1, 2, -3])
will yield [1, 1, 2]
List.take(n : int, l : list('a)) : list('a)
Takes n
first elements of l
. Fails if n
is negative. If n
is greater than length of a list it will return whole list.
List.drop(n : int, l : list('a)) : list('a)
Removes n
first elements of l
. Fails if n
is negative. If n
is greater than length of a list it will return []
.
List.take_while(p : 'a => bool, l : list('a)) : list('a)
Returns longest prefix of l
in which all elements fulfill p
.
List.drop_while(p : 'a => bool, l : list('a)) : list('a)
Removes longest prefix from l
in which all elements fulfill p
.
List.partition(p : 'a => bool, l : list('a)) : (list('a) * list('a))
Separates elements of l
that fulfill p
and these that do not. Elements fulfilling predicate will be in the right list. For instance
partition((x) => x > 0, [-1, 1, -2, 0, 1, 2, -3])
will yield ([1, 1, 2], [-1, -2, 0, -3])
List.flatten(ll : list(list('a))) : list('a)
Flattens a list of lists into a one list.
List.all(p : 'a => bool, l : list('a)) : bool
Checks if all elements of a list fulfill predicate p
.
List.any(p : 'a => bool, l : list('a)) : bool
Checks if any element of a list fulfills predicate p
.
List.sum(l : list(int)) : int
Sums elements of a list. Returns 0 if the list is empty.
List.product(l : list(int)) : int
Multiplies elements of a list. Returns 1 if the list is empty.
List.zip_with(f : ('a, 'b) => 'c, l1 : list('a), l2 : list('b)) : list('c)
"zips" two lists with a function. n-th element of resulting list will be equal to f(x1, x2)
where x1
and x2
are n-th elements of l1
and l2
respectively. Will cut off the tail of the longer list. For instance
zip_with((a, b) => a + b, [1,2], [1,2,3])
will yield [2,4]
List.zip(l1 : list('a), l2 : list('b)) : list('a * 'b)
Special case of zip_with where the zipping function is (a, b) => (a, b)
.
List.unzip(l : list('a * 'b)) : list('a) * list('b)
Opposite to the zip
operation. Takes a list of pairs and returns pair of lists with respective elements on same indices.
List.merge(lesser_cmp : ('a, 'a) => bool, l1 : list('a), l2 : list('a)) : list('a)
Merges two sorted lists into a single sorted list. O(length(l1) + length(l2))
List.sort(lesser_cmp : ('a, 'a) => bool, l : list('a)) : list('a)
Sorts a list using given comparator. lesser_cmp(x, y)
should return true
iff x < y
. If lesser_cmp
is not transitive or there exists an element x
such that lesser_cmp(x, x)
or there exists a pair of elements x
and y
such that lesser_cmp(x, y) && lesser_cmp(y, x)
then the result is undefined. O(length(l) * log_2(length(l))).
List.intersperse(delim : 'a, l : list('a)) : list('a)
Intersperses elements of l
with delim
. Does nothing on empty lists and singletons. For instance
intersperse(0, [1, 2, 3, 4])
will yield [1, 0, 2, 0, 3, 0, 4]
List.enumerate(l : list('a)) : list(int * 'a)
Equivalent to zip with [0..length(l)]
, but slightly faster.
Common operations on option
types and lists of option
s.
Option.is_none(o : option('a)) : bool
Returns true iff o == None
Option.is_some(o : option('a)) : bool
Returns true iff o
is not None
.
Option.match(n : 'b, s : 'a => 'b, o : option('a)) : 'b
Behaves like pattern matching on option
using two case functions.
Option.default(def : 'a, o : option('a)) : 'a
Escapes option
wrapping by providing default value for None
.
Option.force(o : option('a)) : 'a
Forcefully escapes the option
wrapping assuming it is Some
.
Aborts on None
.
Option.force_msg(o : option('a), err : string) : 'a
Forcefully escapes the option
wrapping assuming it is Some
.
Aborts with err
error message on None
.
Option.contains(e : 'a, o : option('a)) : bool
Returns true
if and only if o
contains element equal to e
. Equivalent to Option.match(false, x => x == e, o)
.
Option.on_elem(o : option('a), f : 'a => unit) : unit
Evaluates f
on element under Some
. Does nothing on None
.
Option.map(f : 'a => 'b, o : option('a)) : option('b)
Maps element under Some
. Leaves None
unchanged.
Option.map2(f : ('a, 'b) => 'c, o1 : option('a), o2 : option('b)) : option('c)
Applies arity 2 function over two option
s' elements. Returns Some
iff both of o1
and o2
were Some
, or None
otherwise. For instance
map2((a, b) => a + b, Some(1), Some(2))
will yield Some(3)
and
map2((a, b) => a + b, Some(1), None)
will yield None
.
Option.map3(f : ('a, 'b, 'c) => 'd, o1 : option('a), o2 : option('b), o3 : option('c)) : option('d)
Same as map2 but with arity 3 function.
Option.app_over(f : option ('a => 'b), o : option('a)) : option('b)
Applies function under option
over argument under option
. If either of them is None
the result will be None
as well. For instance
app_over(Some((x) => x + 1), Some(1))
will yield Some(2)
and
app_over(Some((x) => x + 1), None)
will yield None
.
Option.flat_map(f : 'a => option('b), o : option('a)) : option('b)
Performs monadic bind on an option
. Extracts element from o
(if present) and forms new option
from it. For instance
flat_map((x) => Some(x + 1), Some(1))
will yield Some(2)
and
flat_map((x) => Some(x + 1), None)
will yield None
.
Option.to_list(o : option('a)) : list('a)
Turns o
into an empty (if None
) or singleton (if Some
) list.
Option.filter_options(l : list(option('a))) : list('a)
Removes None
s from list and unpacks all remaining Some
s. For instance
filter_options([Some(1), None, Some(2)])
will yield [1, 2]
.
Option.seq_options(l : list (option('a))) : option (list('a))
Tries to unpack all elements of a list from Some
s. Returns None
if at least element of l
is None
. For instance
seq_options([Some(1), Some(2)])
will yield Some([1, 2])
, but
seq_options([Some(1), Some(2), None])
will yield None
.
Option.choose(o1 : option('a), o2 : option('a)) : option('a)
Out of two option
s choose the one that is Some
, or None
if both are None
s.
Option.choose_first(l : list(option('a))) : option('a)
Same as choose, but chooses from a list insted of two arguments.
Common operations on 2-tuples.
Pair.fst(t : ('a * 'b)) : 'a
First element projection.
Pair.snd(t : ('a * 'b)) : 'b
Second element projection.
Pair.map1(f : 'a => 'c, t : ('a * 'b)) : ('c * 'b)
Applies function over first element.
Pair.map2(f : 'b => 'c, t : ('a * 'b)) : ('a * 'c)
Applies function over second element.
Pair.bimap(f : 'a => 'c, g : 'b => 'd, t : ('a * 'b)) : ('c * 'd)
Applies functions over respective elements.
Pair.swap(t : ('a * 'b)) : ('b * 'a)
Swaps elements.
record set('a) = { to_map : map('a, unit) }
Set.new() : set('a)
Returns an empty set
member(e : 'a, s : set('a)) : bool
Checks if the element e
is present in the set s
insert(e : 'a, s : set('a)) : set('a)
Inserts the element e
in the set s
Set.delete(e : 'a, s : set('a)) : set('a)
Removes the element e
from the set s
size(s : set('a)) : int
Returns the number of elements in the set s
Set.to_list(s : set('a)) : list('a)
Returns a list containing the elements of the set s
Set.from_list(l : list('a)) : set('a)
Turns the list l
into a set
Set.filter(p : 'a => bool, s : set('a)) : set('a)
Filters out elements of s
that fulfill predicate p
Set.fold(f : ('a, 'b) => 'b, acc : 'b, s : set('a)) : 'b
Folds the function f
over every element in the set s
and returns the final value of the accumulator acc
.
Set.subtract(s1 : set('a), s2 : set('a)) : set('a)
Returns the elements of s1
that are not members of s2
Set.intersection(s1 : set('a), s2 : set('a)) : set('a)
Returns the intersection of the two sets s1
and s2
Set.intersection_list(sets : list(set('a))) : set('a)
Returns the intersection of all the sets in the given list
Set.union(s1 : set('a), s2 : set('a)) : set('a)
Returns the union of the two sets s1
and s2
Set.union_list(sets : list(set('a))) : set('a)
Returns the union of all the sets in the given list
Operations on the string
type. A string
is a UTF-8 encoded byte array.
length(s : string) : int
The length of a string.
Note: not equivalent to byte size of the string, rather List.length(String.to_list(s))
concat(s1 : string, s2 : string) : string
Concatenates s1
and s2
.
concats(ss : list(string)) : string
Concatenates a list of strings.
to_list(s : string) : list(char)
Converts a string
to a list of char
- the code points are normalized, but
composite characters are possibly converted to multiple char
s. For example the
string "😜i̇" is converted to [128540,105,775]
- where the smiley is the first
code point and the strangely dotted i
becomes [105, 775]
.
from_list(cs : list(char)) : string
Converts a list of characters into a normalized UTF-8 string.
to_lower(s : string) : string
Converts a string to lowercase.
to_upper(s : string) : string
Converts a string to uppercase.
at(ix : int, s : string) : option(char)
Returns the character/codepoint at (zero-based) index ix
. Basically the equivalent to
List.nth(ix, String.to_list(s))
.
split(ix : int, s:string) : string * string
Splits a string at (zero-based) index ix
.
contains(str : string, pat : string) : option(int)
Searches for pat
in str
, returning Some(ix)
if pat
is a substring of
str
starting at position ix
, otherwise returns None
.
tokens(str : string, pat : string) : list(string)
Splits str
into tokens, pat
is the divider of tokens.
to_int(s : string) : option(int)
Converts a decimal ("123", "-253") or a hexadecimal ("0xa2f", "-0xBBB") string into
an integer. If the string doesn't contain a valid number None
is returned.
to_bytes(s : string) : bytes()
Converts string into byte array. String is UTF-8 encoded. I.e.
String.length(s)
is not guaranteed to be equal to
Bytes.size(String.to_bytes(s))
.
sha3(s : string) : hash
Computes the SHA3/Keccak hash of the string.
sha256(s : string) : hash
Computes the SHA256 hash of the string.
blake2b(s : string) : hash
Computes the Blake2B hash of the string.
Triple.fst(t : ('a * 'b * 'c)) : 'a
First element projection.
Triple.snd(t : ('a * 'b * 'c)) : 'b
Second element projection.
Triple.thd(t : ('a * 'b * 'c)) : 'c
Third element projection.
Triple.map1(f : 'a => 'm, t : ('a * 'b * 'c)) : ('m * 'b * 'c)
Applies function over first element.
Triple.map2(f : 'b => 'm, t : ('a * 'b * 'c)) : ('a * 'm * 'c)
Applies function over second element.
Triple.map3(f : 'c => 'm, t : ('a * 'b * 'c)) : ('a * 'b * 'm)
Applies function over third element.
Triple.trimap(f : 'a => 'x, g : 'b => 'y, h : 'c => 'z, t : ('a * 'b * 'c)) : ('x * 'y * 'z)
Applies functions over respective elements.
Triple.swap(t : ('a * 'b * 'c)) : ('c * 'b * 'a)
Swaps first and third element.
Triple.rotr(t : ('a * 'b * 'c)) : ('c * 'a * 'b)
Cyclic rotation of the elements to the right.
Triple.rotl(t : ('a * 'b * 'c)) : ('b * 'c * 'a)
Cyclic rotation of the elements to the left.