Module ContingentClaims.Core.Internal.Claim

Data Types

data Claim t x a o

Core data type used to model cashflows of instruments. Check out the Daml Finance documentation(https://digital-asset.github.io/daml-finance/concepts/contingent-claims.html) for a detailed explanation. In the reference paper from Peyton-Jones this is called ‘Contract’. We renamed it to avoid ambiguity.

• t and x respectively correspond to the Observation input type and the resulting output type. An observation is a function from t to x. A common choice is to use Time and Decimal, respectively.
• a is the representation of an asset, e.g. a Text ISIN code.
• o is the representation of an observable, e.g. a Text.

You should build the Claim using the smart constructors (e.g. zero, and) instead of using the data constructors directly (Zero, And).

Zero

Represents an absence of claims. Monoid And identity.

One a

The bearer acquires one unit of a immediately.

Give (Claim t x a o)

The obligations of the bearer and issuer are reversed.

And

Used to combine multiple rights together.

Field	Type	Description
fst	Claim t x a o
snd	Claim t x a o
tail	[Claim t x a o]

Or

Gives the bearer the right to choose between several claims.

Field	Type	Description
fst	Claim t x a o
snd	Claim t x a o
tail	[Claim t x a o]

Cond

Gives the bearer the right to the first claim if predicate is true, else the second claim.

Field	Type	Description
predicate	Inequality t x o
success	Claim t x a o
failure	Claim t x a o

Scale

Multiplies the claim by k (which can be non-deterministic).

Field	Type	Description
k	Observation t x o
claim	Claim t x a o

When

Defers the acquisition of claim until the first instant that predicate is true.

Field	Type	Description
predicate	Inequality t x o
claim	Claim t x a o

Anytime

Like When, but valid any time the predicate is true (not just infinium).

Field	Type	Description
predicate	Inequality t x o
claim	Claim t x a o

Until

Expires said claim on the first instant that predicate is true.

Field	Type	Description
predicate	Inequality t x o
claim	Claim t x a o

instance Corecursive (Claim t x a o) (ClaimF t x a o)

instance Recursive (Claim t x a o) (ClaimF t x a o)

instance (Eq a, Eq x, Eq o, Eq t) => Eq (Claim t x a o)

instance (Show t, Show x, Show a, Show o) => Show (Claim t x a o)

instance Monoid (Claim t x a o)

instance Semigroup (Claim t x a o)

data Inequality t x o

Data type for boolean predicates supported by the library. A boolean predicate is a generic function with signature t -> x -> Bool. However, a lmited set of predicates is currently supported.

TimeGte t

True when time ≥ t, False otherwise.

TimeLte t

True when time ≤ t, False otherwise.

Lte (Observation t x o, Observation t x o)

True when o(t, x) ≤ o'(t, x), False otherwise for a pair of observations o, o'.

instance (Eq t, Eq x, Eq o) => Eq (Inequality t x o)

instance (Show t, Show x, Show o) => Show (Inequality t x o)