Plutus.V1.Ledger.Scripts

• 1. 📜 Overview

• 2. 🔧 LANGUAGE PRAGMAS AND IMPORTS

• 3. 🗄️ Core Types

  • 3.1 🖥️ Script

  • 3.2 📐 Validator, MintingPolicy, StakeValidator

  • 3.3 📊 Datum, Redeemer, Context

  • 3.4 🔑 Hash Types

  • 3.5 ⚙️ ScriptError

• 4. ⚙️ Key Functions

  • 4.1 📏 scriptSize

  • 4.2 🔄 fromCompiledCode

  • 4.3 🏗️ applyArguments

  • 4.4 🚀 evaluateScript

  • 4.5 🎬 runScript / runMintingPolicyScript / runStakeValidatorScript

  • 4.6 🔗 applyValidator / applyMintingPolicyScript / applyStakeValidatorScript

  • 4.7 📚 unitDatum, unitRedeemer

• 5. 🤝 Typeclass Instances

• 6. 🏭 On-Chain Derivations

• 7. 📚 Glossary

---

1 📜 Overview

The Plutus.V1.Ledger.Scripts module provides the core abstractions and utilities for working with on-chain scripts in Plutus:

• Script: opaque representation of a UPLC program.

• Wrappers: Validator, MintingPolicy, and StakeValidator for specific script roles.

• Data wrappers: Datum, Redeemer, and Context for script inputs.

• Hash types: ScriptHash, ValidatorHash, DatumHash, etc., for script identification.

• Evaluation: functions to apply and run scripts, extracting budgets and logs.

• Utilities: scriptSize, fromCompiledCode, applyArguments, and example unitDatum/unitRedeemer.

---

2 🔧 LANGUAGE PRAGMAS AND IMPORTS

{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE DeriveAnyClass      #-}
{-# LANGUAGE DeriveGeneric       #-}
{-# LANGUAGE DerivingVia         #-}
{-# LANGUAGE FlexibleContexts    #-}
{-# LANGUAGE FlexibleInstances   #-}
{-# LANGUAGE LambdaCase          #-}
{-# LANGUAGE NoImplicitPrelude   #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE PatternSynonyms     #-}
{-# LANGUAGE RankNTypes          #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TemplateHaskell     #-}
{-# LANGUAGE TypeApplications    #-}
{-# LANGUAGE TypeOperators       #-}
{-# LANGUAGE ViewPatterns        #-}

{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# OPTIONS_GHC -fno-specialise     #-}
{-# OPTIONS_GHC -fno-warn-name-shadowing #-}

module Plutus.V1.Ledger.Scripts where

import qualified Prelude                as Haskell
import Codec.Serialise        (Serialise, serialise)
import Codec.CBOR.Extras      (SerialiseViaFlat(..))
import Control.DeepSeq        (NFData)
import Control.Lens           (over)
import Control.Monad.Except   (MonadError, throwError)
import Data.ByteString.Lazy   qualified as BSL
import Data.String            (IsString)
import Data.Text              (Text)
import GHC.Generics           (Generic)
import Plutus.V1.Ledger.Bytes (LedgerBytes(..))
import PlutusTx               (CompiledCode, ToData, FromData, UnsafeFromData, getPlc, makeLift)
import PlutusTx.Builtins      as Builtins
import PlutusTx.Prelude
import Prettyprinter
import Prettyprinter.Extras   (PrettyShow(..))
import PlutusCore             qualified as PLC
import PlutusCore.Data        qualified as PLC
import PlutusCore.MkPlc       qualified as PLC
import UntypedPlutusCore      qualified as UPLC
import UntypedPlutusCore.Check.Scope qualified as UPLC
import UntypedPlutusCore.Evaluation.Machine.Cek qualified as UPLC

• Extensive pragmas for generics, template Haskell, and disabling warnings for orphans and name shadowing.

• Imports for serialization, ByteString, builtins, and untpye UPLC modules.

---

3 🗄️ Core Types

3.1 🖥️ Script

newtype Script = Script { unScript :: UPLC.Program UPLC.DeBruijn PLC.DefaultUni PLC.DefaultFun () }

• Opaque wrapper around UPLC Program.

• Instances: Generic, NFData, Serialise via Flat.

3.2 📐 Validator, MintingPolicy, StakeValidator

newtype Validator = Validator { getValidator :: Script }
newtype MintingPolicy = MintingPolicy { getMintingPolicy :: Script }
newtype StakeValidator = StakeValidator { getStakeValidator :: Script }

• Role-specific wrappers adding Eq, Ord, Serialise, Pretty via LedgerBytes.

3.3 📊 Datum, Redeemer, Context

newtype Datum = Datum { getDatum :: BuiltinData }
newtype Redeemer = Redeemer { getRedeemer :: BuiltinData }
newtype Context = Context BuiltinData

• Wrap BuiltinData for script inputs and blockchain context.

3.4 🔑 Hash Types

newtype ScriptHash = ScriptHash Builtins.BuiltinByteString    deriving via LedgerBytes
newtype ValidatorHash = ValidatorHash Builtins.BuiltinByteString deriving via LedgerBytes
-- similarly: DatumHash, RedeemerHash, MintingPolicyHash, StakeValidatorHash

• String literals via IsString, Eq, Ord, ToData, FromData, UnsafeFromData, Pretty via LedgerBytes.

3.5 ⚙️ ScriptError

data ScriptError = EvaluationError [Text] String | EvaluationException String String

• Captures expected user errors vs internal evaluation exceptions.

---

4 ⚙️ Key Functions

4.1 📏 scriptSize

scriptSize :: Script -> Integer
scriptSize (Script s) = UPLC.programSize s

• Returns serialized program size.

4.2 🔄 fromCompiledCode

fromCompiledCode :: CompiledCode a -> Script

• Converts GHC-compiled Plutus Tx code into nameless Script.

4.3 🏗️ applyArguments

applyArguments :: Script -> [PLC.Data] -> Script

• Applies a list of Data arguments to a UPLC program.

4.4 🚀 evaluateScript

evaluateScript :: MonadError ScriptError m => Script -> m (PLC.ExBudget, [Text])

• Runs the CEK evaluator, returning resource budget and log, or throws ScriptError.

4.5 🎬 runScript / runMintingPolicyScript / runStakeValidatorScript

runScript :: Context -> Validator -> Datum -> Redeemer -> m (PLC.ExBudget,[Text])
runMintingPolicyScript :: Context -> MintingPolicy -> Redeemer -> m (...)
runStakeValidatorScript :: Context -> StakeValidator -> Redeemer -> m (...)

• Helper functions combining application and evaluation.

4.6 🔗 applyValidator / applyMintingPolicyScript / applyStakeValidatorScript

applyValidator :: Context -> Validator -> Datum -> Redeemer -> Script

• Applies wrapper types to produce a Script with applied arguments.

4.7 📚 unitDatum, unitRedeemer

unitDatum :: Datum
unitRedeemer :: Redeemer

• Convenience values for () data.

---

5 🤝 Typeclass Instances

• Eq Script, Ord Script: based on serialized bytes for alpha-equivalence.

• Show Script: prints <Script> placeholder.

• Pretty via PrettyShow for wrappers.

• Functor for applyArguments uses PLC.mkIterApp.

---

6 🏭 On-Chain Derivations

makeLift ''ScriptHash
makeLift ''ValidatorHash
makeLift ''DatumHash
makeLift ''RedeemerHash
makeLift ''MintingPolicyHash
makeLift ''StakeValidatorHash
makeLift ''Datum
makeLift ''Redeemer

• Enables embedding these types in PlutusTx code.

---

7 📚 Glossary

• UPLC: Untyped Plutus Core.

• CEK: evaluation machine for Plutus Core.

• BuiltinData: on-chain data type.

• Script: on-chain program encoded as UPLC.

• Validator/MintingPolicy/StakeValidator: typed script roles.

• Datum/Redeemer/Context: inputs to validators.

• ScriptHash/ValidatorHash/etc.: hashed identifiers for scripts.

• CompiledCode: code produced by PlutusTx compiler plugin.

• SerialiseViaFlat: CBOR using Flat serialization for programs.

• ProgramSize: approximate resource usage metric.

• Alpha-equivalence: program equality modulo renaming.