refactor: moved parser logic to concrete JenaParser class

src/main/kotlin/Main.kt

@@ -17,7 +17,7 @@ fun main(args: Array<String>) = runBlocking {
   val file = File(path)
 
   // Parse said config to a IRPipeline.
-  val parser = Parser(file)
+  val parser = Parser.using(file)
 
   // Parse the pipeline out of the configuration file.
   val pipeline = parser.pipelines[0]

src/main/kotlin/extensions/Model.kt

@@ -2,6 +2,9 @@ package technology.idlab.extensions
 
 import java.io.ByteArrayOutputStream
 import org.apache.jena.rdf.model.Model
+import org.apache.jena.rdf.model.Property
+import org.apache.jena.rdf.model.RDFNode
+import org.apache.jena.rdf.model.Resource
 import org.apache.jena.shacl.ShaclValidator
 import technology.idlab.util.Log
 
@@ -19,3 +22,25 @@ internal fun Model.validate(): Model {
 
   return this
 }
+
+/**
+ * Return the first object which corresponds to a subject and predicate. Returns null if not found.
+ */
+internal fun Model.objectOfProperty(resource: Resource, property: Property): RDFNode? {
+  return try {
+    this.listObjectsOfProperty(resource, property).next()
+  } catch (e: NoSuchElementException) {
+    null
+  }
+}
+
+/**
+ * Return the first subject which corresponds to a predicate and object. Returns null if not found.
+ */
+internal fun Model.subjectWithProperty(property: Property, obj: RDFNode): Resource? {
+  return try {
+    this.listSubjectsWithProperty(property, obj).next()
+  } catch (e: NoSuchElementException) {
+    null
+  }
+}

src/main/kotlin/parser/Parser.kt

@@ -1,81 +1,28 @@
 package technology.idlab.parser
 
 import java.io.File
-import org.apache.jena.ontology.OntModelSpec
-import org.apache.jena.rdf.model.Model
-import org.apache.jena.rdf.model.ModelFactory
-import org.apache.jena.rdf.model.Resource
-import technology.idlab.extensions.validate
-import technology.idlab.parser.impl.parseDependencies
-import technology.idlab.parser.impl.parsePackages
-import technology.idlab.parser.impl.parsePipelines
-import technology.idlab.parser.intermediate.IRDependency
+import technology.idlab.parser.impl.JenaParser
 import technology.idlab.parser.intermediate.IRPackage
 import technology.idlab.parser.intermediate.IRPipeline
 import technology.idlab.parser.intermediate.IRProcessor
-import technology.idlab.resolver.Resolver
 
 /**
  * Parse an RDF file into an intermediate representation, and validate it against the ontology and
  * SHACL shapes.
  */
-class Parser(file: File) {
-  /** The Apache Jena model. */
-  private val model: Model = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM)
-
+abstract class Parser(file: File) {
   /** The pipelines in the current configuration. */
-  val pipelines: List<IRPipeline>
+  abstract val pipelines: List<IRPipeline>
 
   /** The packages in the current configuration. */
-  val packages: List<IRPackage>
+  abstract val packages: List<IRPackage>
 
   /** List of all known processors. */
-  val processors: List<IRProcessor>
-
-  init {
-    // Load the RDF-Connect ontology.
-    val resource = this::class.java.getResource("/pipeline.ttl")
-    val config = resource!!.path!!
-    this.load(config)
-
-    // Load the pipeline file into the parser.
-    this.load(file.path)
-
-    // Retrieve dependencies.
-    val dependencies = this.dependencies()
+  abstract val processors: List<IRProcessor>
 
-    // Resolve all dependencies.
-    dependencies.forEach {
-      val path = Resolver.resolve(it)
-      this.load(path.toString())
+  companion object {
+    fun using(file: File): Parser {
+      return JenaParser(file)
     }
-
-    // Since we updated the model, we will once again check if the SHACL shapes are valid.
-    this.model.validate()
-
-    // Parse the file.
-    this.pipelines = this.pipelines()
-    this.packages = this.packages()
-    this.processors = this.packages.map { it.processors }.flatten()
-  }
-
-  /** Parse the file as a list of pipelines, returning its containing stages and dependencies. */
-  private fun pipelines(): List<IRPipeline> {
-    return model.parsePipelines()
-  }
-
-  /** Parse the model as a list of packages, returning the provided processors inside. */
-  private fun packages(): List<IRPackage> {
-    return model.parsePackages()
-  }
-
-  /** Retrieve all dependencies in a given file. */
-  private fun dependencies(): List<IRDependency> {
-    return model.parseDependencies(null as Resource?)
-  }
-
-  /** Load an additional file into the parser. */
-  private fun load(path: String) {
-    this.model.read(path, "TURTLE")
   }
 }

src/main/kotlin/parser/impl/RDFParser.kt → src/main/kotlin/parser/impl/JenaParser.kt

@@ -1,12 +1,18 @@
 package technology.idlab.parser.impl
 
+import java.io.File
+import org.apache.jena.ontology.OntModelSpec
 import org.apache.jena.rdf.model.Model
-import org.apache.jena.rdf.model.Property
+import org.apache.jena.rdf.model.ModelFactory
 import org.apache.jena.rdf.model.RDFNode
 import org.apache.jena.rdf.model.Resource
 import org.apache.jena.shacl.vocabulary.SHACLM
 import org.apache.jena.vocabulary.RDF
 import runner.Runner
+import technology.idlab.extensions.objectOfProperty
+import technology.idlab.extensions.subjectWithProperty
+import technology.idlab.extensions.validate
+import technology.idlab.parser.Parser
 import technology.idlab.parser.RDFC
 import technology.idlab.parser.intermediate.IRArgument
 import technology.idlab.parser.intermediate.IRDependency
@@ -15,6 +21,7 @@ import technology.idlab.parser.intermediate.IRParameter
 import technology.idlab.parser.intermediate.IRPipeline
 import technology.idlab.parser.intermediate.IRProcessor
 import technology.idlab.parser.intermediate.IRStage
+import technology.idlab.resolver.Resolver
 import technology.idlab.util.Log
 
 internal fun Resource.toRunnerTarget(): Runner.Target {
@@ -44,28 +51,6 @@ internal fun Resource.toIRParameterType(): IRParameter.Type {
   }
 }
 
-/**
- * Return the first object which corresponds to a subject and predicate. Returns null if not found.
- */
-internal fun Model.objectOfProperty(resource: Resource, property: Property): RDFNode? {
-  return try {
-    this.listObjectsOfProperty(resource, property).next()
-  } catch (e: NoSuchElementException) {
-    null
-  }
-}
-
-/**
- * Return the first subject which corresponds to a predicate and object. Returns null if not found.
- */
-internal fun Model.subjectWithProperty(property: Property, obj: RDFNode): Resource? {
-  return try {
-    this.listSubjectsWithProperty(property, obj).next()
-  } catch (e: NoSuchElementException) {
-    null
-  }
-}
-
 /**
  * Create a mapping of String to IRParameter from a SHACL property. This is a recursive
  * implementation that will automatically parse nested classes.
@@ -258,3 +243,64 @@ internal fun Model.parsePipeline(pipeline: Resource): IRPipeline {
 internal fun Model.parsePipelines(): List<IRPipeline> {
   return listSubjectsWithProperty(RDF.type, RDFC.pipeline).toList().map { parsePipeline(it) }
 }
+
+class JenaParser(file: File) : Parser(file) {
+  /** The Apache Jena model. */
+  private val model: Model = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM)
+
+  /** The pipelines in the current configuration. */
+  override val pipelines: List<IRPipeline>
+
+  /** The packages in the current configuration. */
+  override val packages: List<IRPackage>
+
+  /** List of all known processors. */
+  override val processors: List<IRProcessor>
+
+  init {
+    // Load the RDF-Connect ontology.
+    val resource = this::class.java.getResource("/pipeline.ttl")
+    val config = resource!!.path!!
+    this.load(config)
+
+    // Load the pipeline file into the parser.
+    this.load(file.path)
+
+    // Retrieve dependencies.
+    val dependencies = this.dependencies()
+
+    // Resolve all dependencies.
+    dependencies.forEach {
+      val path = Resolver.resolve(it)
+      this.load(path.toString())
+    }
+
+    // Since we updated the model, we will once again check if the SHACL shapes are valid.
+    this.model.validate()
+
+    // Parse the file.
+    this.pipelines = this.pipelines()
+    this.packages = this.packages()
+    this.processors = this.packages.map { it.processors }.flatten()
+  }
+
+  /** Parse the file as a list of pipelines, returning its containing stages and dependencies. */
+  private fun pipelines(): List<IRPipeline> {
+    return model.parsePipelines()
+  }
+
+  /** Parse the model as a list of packages, returning the provided processors inside. */
+  private fun packages(): List<IRPackage> {
+    return model.parsePackages()
+  }
+
+  /** Retrieve all dependencies in a given file. */
+  private fun dependencies(): List<IRDependency> {
+    return model.parseDependencies(null as Resource?)
+  }
+
+  /** Load an additional file into the parser. */
+  private fun load(path: String) {
+    this.model.read(path, "TURTLE")
+  }
+}

src/test/kotlin/parser/ParserTest.kt

@@ -14,7 +14,7 @@ class ParserTest {
   private fun parse(resource: String): Parser {
     val uri = this::class.java.getResource(resource)
     val file = File(uri!!.toURI())
-    return Parser(file)
+    return Parser.using(file)
   }
 
   @Test
@@ -102,7 +102,7 @@ class ParserTest {
   fun stages() {
     val uri = this::class.java.getResource("/pipelines/basic/index.ttl")
     val file = File(uri!!.toURI())
-    val parser = Parser(file)
+    val parser = Parser.using(file)
 
     val stages = parser.pipelines[0].stages