refactor: use mixins instead of exports

Author: kelvin-olaiya

src/main/scala/io/github/kelvindev15/prolog/dsl/DSLConversions.scala

@@ -4,7 +4,8 @@ import io.github.kelvindev15.prolog.core.Constant.Atom
 import io.github.kelvindev15.prolog.core.Struct.Fact
 import io.github.kelvindev15.prolog.core.{Constant, PrologList, Struct, Term}
 
-object DSLConversions:
+trait DSLConversions:
+  dsl: PrologDSL =>
   given Conversion[String, Atom] = Atom(_)
   given Conversion[AnyVal, Constant.Numeric] = Constant.Numeric(_)
   given Conversion[Struct, Fact] = Fact(_)

src/main/scala/io/github/kelvindev15/prolog/dsl/DSLExtensions.scala

@@ -6,7 +6,8 @@ import io.github.kelvindev15.prolog.core.{Goals, PrologList, Struct, Term}
 
 import scala.annotation.targetName
 
-object DSLExtensions:
+trait DSLExtensions:
+  dsl: PrologDSL =>
   extension (atom: Atom)
     def apply(terms: Term*): Struct = Struct(atom, terms *)
 

src/main/scala/io/github/kelvindev15/prolog/dsl/DSLFacilities.scala

@@ -11,7 +11,8 @@ enum AssociativitySpec extends Atom:
   case fx, fy, xf, xfx, xfy, yfx, yfy
   override val value: String = toString
 
-object DSLPrologBuiltins:
+trait DSLPrologBuiltins:
+  dsl: PrologDSL =>
   export AssociativitySpec.*
 
   @targetName("iff")

src/main/scala/io/github/kelvindev15/prolog/dsl/DSLPrologBuiltins.scala

@@ -2,7 +2,8 @@ package io.github.kelvindev15.prolog.dsl
 
 import io.github.kelvindev15.prolog.core.Variable
 
-object DSLVariables:
+trait DSLVariables:
+  dsl: PrologDSL =>
   def `__`: Variable = Variable.anonymous()
   def A: Variable = Variable("A")
   def B: Variable = Variable("B")

src/main/scala/io/github/kelvindev15/prolog/dsl/DSLVariables.scala

@@ -7,9 +7,7 @@ import io.github.kelvindev15.prolog.core.{PrologList, Term, Variable}
 
 import scala.annotation.targetName
 
-trait PrologDSL:
-  export DSLFacilities.{*, given}
-  export DSLVariables.*
+trait PrologDSL extends DSLPrologBuiltins with DSLExtensions with DSLVariables with DSLConversions:
 
   def theory(clauses: Clause*): Theory = Theory(clauses*)