feat: cli versions

pkg/codec/codec.go

@@ -1,12 +1,8 @@
 package codec
 
-import "git.maximhutz.com/max/lambda/pkg/repr"
-
-type String string
-
-func (s String) Id() string { return "string" }
-
-type Codec[T, U repr.Repr] interface {
+type Codec[T, U any] interface {
 	Encode(T) (U, error)
 	Decode(U) (T, error)
 }
+
+type Marshaler[T any] = Codec[T, string]

pkg/engine/engine.go

@@ -0,0 +1,7 @@
+package engine
+
+type Engine[T any] interface {
+	Get() (T, error)
+	Set(T) error
+	Step(int) bool
+}

pkg/lambda/expression.go

@@ -3,14 +3,12 @@ package lambda
 import (
 	"fmt"
 
-	"git.maximhutz.com/max/lambda/pkg/repr"
 	"git.maximhutz.com/max/lambda/pkg/set"
 )
 
 // Expression is the interface for all lambda calculus expression types.
 // It embeds the general expr.Expression interface for cross-mode compatibility.
 type Expression interface {
-	repr.Repr
 	fmt.Stringer
 
 	// Substitute replaces all free occurrences of the target variable with the
@@ -40,8 +38,6 @@ type Abstraction struct {
 
 var _ Expression = Abstraction{}
 
-func (a Abstraction) Id() string { return "lambda" }
-
 func (a Abstraction) Parameter() string {
 	return a.parameter
 }
@@ -67,8 +63,6 @@ type Application struct {
 
 var _ Expression = Application{}
 
-func (a Application) Id() string { return "lambda" }
-
 func (a Application) Abstraction() Expression {
 	return a.abstraction
 }
@@ -93,8 +87,6 @@ type Variable struct {
 
 var _ Expression = Variable{}
 
-func (a Variable) Id() string { return "lambda" }
-
 func (v Variable) Name() string {
 	return v.name
 }

pkg/normalorder/reduce_once.go

@@ -1,34 +0,0 @@
-package normalorder
-
-import "git.maximhutz.com/max/lambda/pkg/lambda"
-
-func ReduceOnce(e lambda.Expression) (lambda.Expression, bool) {
-	switch e := e.(type) {
-	case lambda.Abstraction:
-		body, reduced := ReduceOnce(e.Body())
-		if reduced {
-			return lambda.NewAbstraction(e.Parameter(), body), true
-		}
-		return e, false
-
-	case lambda.Application:
-		if fn, fnOk := e.Abstraction().(lambda.Abstraction); fnOk {
-			return fn.Body().Substitute(fn.Parameter(), e.Argument()), true
-		}
-
-		abs, reduced := ReduceOnce(e.Abstraction())
-		if reduced {
-			return lambda.NewApplication(abs, e.Argument()), true
-		}
-
-		arg, reduced := ReduceOnce(e.Argument())
-		if reduced {
-			return lambda.NewApplication(e.Abstraction(), arg), true
-		}
-
-		return e, false
-
-	default:
-		return e, false
-	}
-}

pkg/normalorder/runtime.go

@@ -1,46 +0,0 @@
-package normalorder
-
-import (
-	"git.maximhutz.com/max/lambda/pkg/emitter"
-	"git.maximhutz.com/max/lambda/pkg/lambda"
-	"git.maximhutz.com/max/lambda/pkg/repr"
-	"git.maximhutz.com/max/lambda/pkg/runtime"
-)
-
-// NormalOrderReducer implements normal order (leftmost-outermost) reduction
-// for lambda calculus expressions.
-type Runtime struct {
-	emitter.BaseEmitter[runtime.Event]
-	expression lambda.Expression
-}
-
-// NewNormalOrderReducer creates a new normal order reducer.
-func NewRuntime(expression lambda.Expression) *Runtime {
-	return &Runtime{
-		BaseEmitter: *emitter.New[runtime.Event](),
-		expression:  expression,
-	}
-}
-
-// Expression returns the current expression state.
-func (r *Runtime) Expression() repr.Repr {
-	return r.expression
-}
-
-func (r *Runtime) Step() bool {
-	result, done := ReduceOnce(r.expression)
-	r.expression = result
-	return !done
-}
-
-// Reduce performs normal order reduction on a lambda expression.
-// The expression must be a lambda.Expression; other types are returned unchanged.
-func (r *Runtime) Run() {
-	r.Emit(runtime.StartEvent)
-
-	for !r.Step() {
-		r.Emit(runtime.StepEvent)
-	}
-
-	r.Emit(runtime.StopEvent)
-}

pkg/repr/repr.go

@@ -1,15 +0,0 @@
-// Package repr defines a general definition of a representation of lambda
-// calculus.
-package repr
-
-import "fmt"
-
-// Repr is a representation of lambda calculus.
-type Repr interface {
-	fmt.Stringer
-
-	// Id returns to name of the objects underlying representation. If is
-	// assumed that if two Repr objects have the same Id(), they share the same
-	// representation.
-	Id() string
-}

pkg/runtime/events.go

@@ -1,13 +0,0 @@
-package runtime
-
-// Event represents lifecycle events during interpretation.
-type Event int
-
-const (
-	// StartEvent is emitted before interpretation begins.
-	StartEvent Event = iota
-	// StepEvent is emitted after each interpretation step.
-	StepEvent
-	// StopEvent is emitted after interpretation completes.
-	StopEvent
-)

pkg/runtime/runtime.go

@@ -1,27 +0,0 @@
-// Package runtime provides the abstract Reducer interface for all expression
-// reduction strategies.
-package runtime
-
-import (
-	"git.maximhutz.com/max/lambda/pkg/emitter"
-	"git.maximhutz.com/max/lambda/pkg/repr"
-)
-
-// Runtime defines the interface for expression reduction strategies.
-// Different evaluation modes (normal order, applicative order, SKI combinators,
-// etc.) implement this interface with their own reduction logic.
-//
-// Runtimes also implement the Emitter interface to allow plugins to observe
-// reduction lifecycle events (Start, Step, Stop).
-type Runtime interface {
-	emitter.Emitter[Event]
-
-	// Run a single step. Returns whether the runtime is complete or not.
-	Step() bool
-
-	// Run until completion.
-	Run()
-
-	// Copy the state of the runtime.
-	Expression() repr.Repr
-}