std.value, std.valueMap, std.credential

Pebble 0.3.1 · all symbols on this page are stable.

Function-shaped views of the methods on the native Value, the legacy ValueMap representation, and Credential. The method-call forms (v.amountOf(...), cred.hash()) are what you'll use day-to-day — these namespaces exist so the same operations can be passed as values.

using { amountOf, lovelaces, union } = std.value;

const adaPaid = lovelaces(tx.outputs[0].value);
const totalOut = std.list.foldl(union, mempty, tx.outputs.map((o) => o.value));

std.value

Function	Description
amountOf(policy: PolicyId, name: TokenName, v: Value): int	Amount of (policy, name) in v. 0 if absent.
lovelaces(v: Value): int	Amount of ADA (the ada/lovelace entry).
insert(policy: PolicyId, name: TokenName, amount: int, v: Value): Value	Set the amount of (policy, name) in v. Pass 0 to remove.
union(a: Value, b: Value): Value	Asset-wise sum.
contains(a: Value, b: Value): bool	True iff a ≥ b for every asset (b is a sub-value of a).
scale(k: int, v: Value): Value	Multiply every amount in v by k.
toData(v: Value): data	CBOR-encode (mirrors ToData).

std.valueMap

Methods on the legacy ValueMap representation (an assoc-list of assoc-lists, used by older script contexts and on-chain types). Native Value is preferred for new code.

Function	Description
amountOf(policy: PolicyId, name: TokenName, vm: ValueMap): int	Amount of (policy, name) in vm. 0 if absent.
lovelaces(vm: ValueMap): int	Amount of ADA.

std.credential

Function	Description
hash(c: Credential): bytes	The underlying hash of a Credential (pubkey-hash or script-hash).

Examples

std.value

using { amountOf, lovelaces, insert, union, contains, scale, toData } = std.value;

const v:  Value = insert(myPolicy, myToken, 5, mempty);    // {myPolicy/myToken: 5}
const a:  int   = amountOf(myPolicy, myToken, v);          // 5
const l:  int   = lovelaces(tx.outputs[0].value);          // ADA in lovelace
const u:  Value = union(v, v);                             // 2× v
const ok: bool  = contains(u, v);                          // true
const s:  Value = scale(3, v);                             // 3× v
const d:  data  = toData(v);

std.valueMap

using { amountOf, lovelaces } = std.valueMap;

const a: int = amountOf(myPolicy, myToken, legacyValueMap);
const l: int = lovelaces(legacyValueMap);

std.credential

using { hash } = std.credential;

const h: bytes = hash(tx.outputs[0].address.paymentCredential);

See also

• Value — method-call surface and the type definition
• Address, Credential — the structures that carry a Credential
• std.builtins — the underlying insertCoin, lookupCoin, unionValue, etc.