BaseSimpleLowering

Lower the SIR to UPLC Term

Check if a constructor name is a Data type constructor.

Check if a SIR type is the builtin Data type.

Check if a scrutinee type is a known Data variant (I, B, List, Map, Constr).

Lower a single case branch for Data pattern matching (PlutusV3).

For V3 chooseData, branches are thunks that reference a pre-bound scrutinee. We extract values from the scrutinee within each branch.

Lower a single case branch for Data pattern matching (PlutusV4).

For V4 Case on Data, branches are lambdas that receive the inner values directly:

• Constr: \tag args -> body
• Map: \entries -> body
• List: \elements -> body
• I: \value -> body
• B: \value -> body

Even for wildcards/no-bindings, we need lambdas that ignore the inner values.

Lower a Data constructor expression to UPLC.

Data constructors are lowered to their corresponding builtin functions:

• Data.I(value) → iData(value)
• Data.B(value) → bData(value)
• Data.List(values) → listData(values)
• Data.Map(values) → mapData(values)
• Data.Constr(tag, args) → constrData(tag, args)

Lower a match expression on Data type.

Data has 5 constructors in a fixed order:

• 0: Constr (tag: Integer, args: List[Data])
• 1: Map (entries: List[(Data, Data)])
• 2: List (elements: List[Data])
• 3: I (value: Integer)
• 4: B (value: ByteString)

For PlutusV4, use Case on Data instruction. For PlutusV3 and earlier, use chooseData builtin.

For V4 Case on Data:

• Branches are lambdas that receive the inner values
• Constr branch: \tag args -> body
• Other branches: \value -> body

For V3 chooseData:

• chooseData just selects a delayed branch, it doesn't pass arguments
• We bind the scrutinee first, then extract values within each branch

Lower a field selection on Data type.

Data field selections are lowered to their corresponding builtin unpack functions:

• Data.I.value → unIData(scrutinee)
• Data.B.value → unBData(scrutinee)
• Data.List.values → unListData(scrutinee)
• Data.Map.values → unMapData(scrutinee)
• Data.Constr.constr → fstPair(unConstrData(scrutinee))
• Data.Constr.args → sndPair(unConstrData(scrutinee))