haskledger

License	Apache-2.0
Stability	provisional
Safe Haskell	None
Language	Haskell2010

HaskLedger.Combinators

Contents

Convenience combinators
Operators
Script context access
TxInfo field access
Data conversion
Integer comparisons
Time range operations
Boolean combinators

Description

Combinators and operators for accessing ledger data and expressing conditions within a HaskLedger contract.

All combinators take monadic Contract Expr arguments so let-bindings work naturally in do blocks.

Synopsis

theRedeemer :: Contract Expr
theTxInfo :: Contract Expr
txValidRange :: Contract Expr
(.==) :: Contract Expr -> Contract Expr -> Contract Condition
(./=) :: Contract Expr -> Contract Expr -> Contract Condition
(.<) :: Contract Expr -> Contract Expr -> Contract Condition
(.<=) :: Contract Expr -> Contract Expr -> Contract Condition
(.>) :: Contract Expr -> Contract Expr -> Contract Condition
(.>=) :: Contract Expr -> Contract Expr -> Contract Condition
(.&&) :: Contract Condition -> Contract Condition -> Contract Condition
(.||) :: Contract Condition -> Contract Condition -> Contract Condition
scriptContext :: Contract Expr
txInfo :: Contract Expr -> Contract Expr
redeemer :: Contract Expr -> Contract Expr
validRange :: Contract Expr -> Contract Expr
asInt :: Contract Expr -> Contract Expr
mkInt :: Integer -> Contract Expr
equalsInt :: Contract Expr -> Contract Expr -> Contract Condition
lessThanInt :: Contract Expr -> Contract Expr -> Contract Condition
lessThanEqInt :: Contract Expr -> Contract Expr -> Contract Condition
after :: Contract Expr -> Contract Expr -> Contract Condition
andBool :: Contract Condition -> Contract Condition -> Contract Condition
orBool :: Contract Condition -> Contract Condition -> Contract Condition
notBool :: Contract Condition -> Contract Condition

Convenience combinators

theRedeemer :: Contract Expr #

The redeemer from the script context, as raw Data.

theTxInfo :: Contract Expr #

The TxInfo record from the script context, as raw Data.

txValidRange :: Contract Expr #

The transaction validity range (Interval POSIXTime), as raw Data.

Operators

(.==) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer equality (EqualsInteger).

(./=) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer inequality. notBool (a .== b).

(.<) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer strict less-than (LessThanInteger).

(.<=) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer less-than-or-equal (LessThanEqualsInteger).

(.>) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer strict greater-than. flip (.<).

(.>=) :: Contract Expr -> Contract Expr -> Contract Condition infix 4 #

Integer greater-than-or-equal. flip (.<=).

(.&&) :: Contract Condition -> Contract Condition -> Contract Condition infixr 3 #

Logical AND. Compiles to IfThenElse a b False. Both operands evaluated eagerly.

(.||) :: Contract Condition -> Contract Condition -> Contract Condition infixr 2 #

Logical OR. Compiles to IfThenElse a True b. Both operands evaluated eagerly.

Script context access

scriptContext :: Contract Expr #

The raw script context Data - the single argument to every PlutusV3 validator.

txInfo :: Contract Expr -> Contract Expr #

Extract TxInfo from a script context (field 0).

redeemer :: Contract Expr -> Contract Expr #

Extract the redeemer from a script context (field 1).

TxInfo field access

validRange :: Contract Expr -> Contract Expr #

Extract the validity range from TxInfo (field 7).

Data conversion

asInt :: Contract Expr -> Contract Expr #

Interpret a Data value as an integer (UnIData).

mkInt :: Integer -> Contract Expr #

Construct an on-chain integer literal. Usually unnecessary - the Num instance lets you write 42 directly.

Integer comparisons

equalsInt :: Contract Expr -> Contract Expr -> Contract Condition #

EqualsInteger. Prefer .==.

lessThanInt :: Contract Expr -> Contract Expr -> Contract Condition #

LessThanInteger. Prefer .<.

lessThanEqInt :: Contract Expr -> Contract Expr -> Contract Condition #

LessThanEqualsInteger. Prefer .<=.

Time range operations

after :: Contract Expr -> Contract Expr -> Contract Condition #

Check that a validity range starts at or after a deadline.

The deadline is a POSIX timestamp in milliseconds (Cardano's on-chain unit).

Walks the Interval POSIXTime encoding to extract the lower bound, reads the closure flag, and compares against the deadline. Closed (inclusive) bounds check deadline <= time; open (exclusive) bounds check deadline <= time + 1. Non-finite bounds (NegInf, PosInf) crash at runtime, which is the correct rejection for a deadline validator.

Boolean combinators

andBool :: Contract Condition -> Contract Condition -> Contract Condition #

Logical AND. IfThenElse a b False. Both operands evaluated eagerly. For short-circuit semantics, use requireAll instead.

orBool :: Contract Condition -> Contract Condition -> Contract Condition #

Logical OR. IfThenElse a True b. Both operands evaluated eagerly.

notBool :: Contract Condition -> Contract Condition #

Logical NOT. IfThenElse cond False True.