Improved RDS parsing

pmml-rexp/src/main/java/org/jpmml/rexp/REnvironment.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2024 Villu Ruusmann
+ *
+ * This file is part of JPMML-R
+ *
+ * JPMML-R is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JPMML-R is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with JPMML-R.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.jpmml.rexp;
+
+abstract
+public class REnvironment extends RExp {
+
+	private RPair variables = null;
+
+
+	REnvironment(){
+		super(null);
+	}
+
+	public RExp findVariable(String name){
+		RPair variable = getVariables();
+
+		while(variable != null){
+
+			if(variable.tagEquals(name)){
+				return variable.getValue();
+			}
+
+			variable = variable.getNext();
+		}
+
+		return null;
+	}
+
+	public RPair getVariables(){
+		return this.variables;
+	}
+
+	void setVariables(RPair variables){
+		this.variables = variables;
+	}
+
+	public static final REnvironment EMPTY = new REnvironment(){
+	};
+}

pmml-rexp/src/main/java/org/jpmml/rexp/RExp.java

@@ -138,7 +138,7 @@ public RPair getAttributes(){
 		return this.attributes;
 	}
 
-	private void setAttributes(RPair attributes){
+	void setAttributes(RPair attributes){
 		this.attributes = attributes;
 	}
 }

pmml-rexp/src/main/java/org/jpmml/rexp/RExpParser.java

@@ -25,7 +25,9 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.zip.GZIPInputStream;
 
 import com.google.common.io.ByteStreams;
@@ -34,6 +36,8 @@ public class RExpParser {
 
 	private RDataInput input = null;
 
+	private Map<RSymbol, REnvironment> namespaces = new LinkedHashMap<>();
+
 	private List<RExp> referenceTable = new ArrayList<>();
 
 
@@ -106,13 +110,13 @@ private RExp readRExp() throws IOException {
 			case SerializationTypes.BASEENVSXP:
 				return null; // XXX
 			case SerializationTypes.EMPTYENVSXP:
-				return null; // XXX
+				return REnvironment.EMPTY;
 			case SerializationTypes.NAMESPACESXP:
 				return readNamespace();
 			case SerializationTypes.BASENAMESPACESXP:
 				return null; // XXX
 			case SerializationTypes.MISSINGARGSXP:
-				return null; // XXX
+				return RSymbol.MISSING_ARG;
 			case SerializationTypes.UNBOUNDVALUESXP:
 				return null; // XXX
 			case SerializationTypes.GLOBALENVSXP:
@@ -182,22 +186,27 @@ private RExp readClosure(int flags) throws IOException {
 		return new RClosure(attributes, environment, parameters, body);
 	}
 
-	private RExp readEnvironment(int flags) throws IOException {
-		RExp rexp = null;
+	private REnvironment readEnvironment(int flags) throws IOException {
+		REnvironment environment = new REnvironment(){
+		};
 
 		readInt();
 
 		// "MUST register before filling in"
-		this.referenceTable.add(rexp);
+		this.referenceTable.add(environment);
 
 		// "Now fill it in"
 		RExp parent = readRExp();
 		RPair frame = (RPair)readRExp();
 		RExp hashtab = readRExp();
 
+		environment.setVariables(frame);
+
 		RPair attributes = (RPair)readRExp();
 
-		return rexp;
+		environment.setAttributes(attributes);
+
+		return environment;
 	}
 
 	private RExp readPromise(int flags) throws IOException {
@@ -343,16 +352,18 @@ private RExp readBytecode(int flags) throws IOException {
 	}
 
 	private RExp readExternalPointer(int flags) throws IOException {
-		RExp rexp = null;
+		RExternalPtr externalPtr = new RExternalPtr(null);
 
-		this.referenceTable.add(rexp);
+		this.referenceTable.add(externalPtr);
 
 		RExp protected_ = readRExp();
 		RExp tag = readRExp();
 
-		readAttributes(flags);
+		RPair attributes = readAttributes(flags);
+
+		externalPtr.setAttributes(attributes);
 
-		return rexp;
+		return externalPtr;
 	}
 
 	private RRaw readRaw(int flags) throws IOException {
@@ -476,11 +487,20 @@ private RExp readNamespace() throws IOException {
 			throw new UnsupportedOperationException();
 		}
 
-		readStringVector(flags);
+		RStringVector name = readStringVector(flags);
 
-		this.referenceTable.add(null);
+		RSymbol symbol = new RSymbol(name.getValue(0));
 
-		return null;
+		REnvironment namespace = this.namespaces.get(symbol);
+		if(namespace == null){
+			namespace = new REnvironment(){};
+
+			this.namespaces.put(symbol, namespace);
+		}
+
+		this.referenceTable.add(namespace);
+
+		return namespace;
 	}
 
 	private RExp readReference(int flags) throws IOException {

pmml-rexp/src/main/java/org/jpmml/rexp/RExternalPtr.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024 Villu Ruusmann
+ *
+ * This file is part of JPMML-R
+ *
+ * JPMML-R is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JPMML-R is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with JPMML-R.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.jpmml.rexp;
+
+public class RExternalPtr extends RExp {
+
+	public RExternalPtr(RPair attributes){
+		super(attributes);
+	}
+}

pmml-rexp/src/main/java/org/jpmml/rexp/RSymbol.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2024 Villu Ruusmann
+ *
+ * This file is part of JPMML-R
+ *
+ * JPMML-R is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JPMML-R is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with JPMML-R.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.jpmml.rexp;
+
+import java.util.Objects;
+
+public class RSymbol extends RExp {
+
+	private String value = null;
+
+
+	public RSymbol(String value){
+		super(null);
+
+		setValue(value);
+	}
+
+	@Override
+	public int hashCode(){
+		return Objects.hashCode(this.getValue());
+	}
+
+	@Override
+	public boolean equals(Object object){
+
+		if(object instanceof RSymbol){
+			RSymbol that = (RSymbol)object;
+
+			return Objects.equals(this.getValue(), that.getValue());
+		}
+
+		return false;
+	}
+
+	public String getValue(){
+		return this.value;
+	}
+
+	private void setValue(String value){
+		this.value = Objects.requireNonNull(value);
+	}
+
+	public static final RSymbol MISSING_ARG = new RSymbol("");
+}