feat: rename repr to expr

internal/registry/process.go

@@ -5,7 +5,7 @@ import (
 )
 
 type Process interface {
-	engine.Process[Repr]
+	engine.Process[Expr]
 
 	InType() string
 }
@@ -17,13 +17,13 @@ type convertedProcess[T any] struct {
 
 func (e convertedProcess[T]) InType() string { return e.inType }
 
-func (b convertedProcess[T]) Get() (Repr, error) {
+func (b convertedProcess[T]) Get() (Expr, error) {
 	s, err := b.process.Get()
 	if err != nil {
 		return nil, err
 	}
 
-	return NewRepr(b.inType, s), nil
+	return NewExpr(b.inType, s), nil
 }
 
 func (b convertedProcess[T]) Step(i int) bool {