r/org.eclipse.statet.r.ui/src/org/eclipse/statet/r/codegeneration/CodeGeneration.java - statet/org.eclipse.statet-r - Git at Google

 /*=============================================================================#
  # Copyright (c) 2005, 2021 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.r.codegeneration;

 import java.util.List;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.text.AbstractDocument;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.templates.Template;
 import org.eclipse.jface.text.templates.TemplateBuffer;
 import org.eclipse.jface.text.templates.TemplateVariable;
 import org.eclipse.osgi.util.NLS;

 import org.eclipse.statet.ecommons.templates.TemplateMessages;

 import org.eclipse.statet.internal.r.ui.RUIPlugin;
 import org.eclipse.statet.ltk.model.core.element.LtkModelElement;
 import org.eclipse.statet.ltk.model.core.element.SourceUnit;
 import org.eclipse.statet.ltk.ui.templates.TemplateUtils;
 import org.eclipse.statet.ltk.ui.templates.TemplateUtils.EvaluatedTemplate;
 import org.eclipse.statet.r.core.BasicRResourceSourceUnit;
 import org.eclipse.statet.r.core.rmodel.RElement;
 import org.eclipse.statet.r.core.rmodel.RLangClass;
 import org.eclipse.statet.r.core.rmodel.RLangMethod;
 import org.eclipse.statet.r.core.rmodel.RLangSlot;
 import org.eclipse.statet.r.core.rmodel.RSourceUnit;
 import org.eclipse.statet.r.ui.RUI;


 /**
  * Class that offers access to the code templates contained.
  */
 public class CodeGeneration {


 	/**
 	 * Generates initial content for a new R script file.
 	 *
 	 * @param su the R source unit to create the source for. The unit does not need to exist
 	 * @param lineDelimiter the line delimiter to be used
 	 * @return the new content or <code>null</code> if the template is undefined or empty
 	 * @throws CoreException thrown when the evaluation of the code template fails
 	 */
 	public static EvaluatedTemplate getNewRFileContent(final RSourceUnit su, final String lineDelimiter) throws CoreException {
 		final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore().findTemplate(RCodeTemplateContextType.NEW_RSCRIPTFILE);
 		if (template == null) {
 			return null;
 		}

 		final RCodeTemplateContext context = new RCodeTemplateContext(
 				RCodeTemplateContextType.NEW_RSCRIPTFILE_CONTEXTTYPE, su, lineDelimiter);

 		try {
 			final TemplateBuffer buffer = context.evaluate(template);
 			if (buffer == null) {
 				return null;
 			}
 			return new TemplateUtils.EvaluatedTemplate(buffer, lineDelimiter);
 		}
 		catch (final Exception e) {
 			throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
 					TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
 		}
 	}

 	/**
 	 * Generates content for the Roxygen comment for the given function definition
 	 * @param rMethod function element
 	 * @param lineDelimiter the line delimiter to be used
 	 * @return
 	 * @throws CoreException thrown when the evaluation of the code template fails
 	 */
 	public static EvaluatedTemplate getCommonFunctionRoxygenComment(final RLangMethod rMethod, final String lineDelimiter) throws CoreException {
 		final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
 				.findTemplate(RCodeTemplateContextType.ROXYGEN_COMMONFUNCTION_TEMPLATE_ID);
 		if (template == null) {
 			return null;
 		}

 		final SourceUnit su = rMethod.getSourceUnit();
 		final RCodeTemplateContext context = new RCodeTemplateContext(
 				RCodeTemplateContextType.ROXYGEN_COMMONFUNCTION_CONTEXTTYPE, su, lineDelimiter);
 		context.setRElement(rMethod);

 		try {
 			final TemplateBuffer buffer = context.evaluate(template);
 			if (buffer == null) {
 				return null;
 			}
 			final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

 			final AbstractDocument content = data.startPostEdit();
 			final StringBuilder tagBuffer = new StringBuilder(64);
 			final TemplateVariable paramVariable = TemplateUtils.findVariable(buffer,
 					RCodeTemplateContextType.ROXYGEN_PARAM_TAGS_VAR_NAME );
 			final Position[] paramPositions = new Position[(paramVariable != null) ? paramVariable.getOffsets().length : 0];
 			for (int i = 0; i < paramPositions.length; i++) {
 				paramPositions[i] = new Position(paramVariable.getOffsets()[i], paramVariable.getLength());
 				content.addPosition(paramPositions[i]);
 			}

 			if (paramPositions.length > 0) {
 				String[] tags = null;
 				final var parameters= rMethod.getParameters();
 				if (parameters != null) {
 					final int count = parameters.size();
 					tags = new String[count];
 					for (int i = 0; i < count; i++) {
 						final String paramName= parameters.get(i).getName();
 						tagBuffer.append("@param "); //$NON-NLS-1$
 						if (paramName != null) {
 							tagBuffer.append(paramName);
 						}
 						tagBuffer.append(" "); //$NON-NLS-1$
 						tags[i] = tagBuffer.toString();
 						tagBuffer.setLength(0);
 					}
 				}
 				for (final Position pos : paramPositions) {
 					insertRoxygen(content, pos, tags);
 				}
 			}

 			data.finishPostEdit();
 			return data;
 		}
 		catch (final Exception e) {
 			throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
 					TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
 		}
 	}

 	/**
 	 * Generates content for the Roxygen comment for the given class definition
 	 * @param rClass class element
 	 * @param lineDelimiter the line delimiter to be used
 	 * @return
 	 * @throws CoreException thrown when the evaluation of the code template fails
 	 */
 	public static EvaluatedTemplate getClassRoxygenComment(final RLangClass rClass, final String lineDelimiter) throws CoreException {
 		final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
 				.findTemplate(RCodeTemplateContextType.ROXYGEN_S4CLASS_TEMPLATE_ID);
 		if (template == null) {
 			return null;
 		}

 		final SourceUnit su = rClass.getSourceUnit();
 		final RCodeTemplateContext context = new RCodeTemplateContext(
 				RCodeTemplateContextType.ROXYGEN_CLASS_CONTEXTTYPE, su, lineDelimiter);
 		context.setRElement(rClass);

 		try {
 			final TemplateBuffer buffer = context.evaluate(template);
 			if (buffer == null) {
 				return null;
 			}
 			final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

 			final AbstractDocument content = data.startPostEdit();
 			final StringBuilder tagBuffer = new StringBuilder(64);
 			final TemplateVariable slotVariable = TemplateUtils.findVariable(buffer,
 					RCodeTemplateContextType.ROXYGEN_SLOT_TAGS_VAR_NAME );
 			final Position[] slotPositions = new Position[(slotVariable != null) ? slotVariable.getOffsets().length : 0];
 			for (int i = 0; i < slotPositions.length; i++) {
 				slotPositions[i] = new Position(slotVariable.getOffsets()[i], slotVariable.getLength());
 				content.addPosition(slotPositions[i]);
 			}

 			if (slotPositions.length > 0) {
 				final List<? extends LtkModelElement> slots = rClass.getModelChildren(RElement.R_S4SLOT_FILTER);
 				final int count = slots.size();
 				final var tags= new String[count];
 				for (int i = 0; i < count; i++) {
 					final RLangSlot slot = (RLangSlot)slots.get(i);
 					tagBuffer.append("@slot "); //$NON-NLS-1$
 					tagBuffer.append(slot.getElementName().getDisplayName());
 					tagBuffer.append(" "); //$NON-NLS-1$
 					tags[i] = tagBuffer.toString();
 					tagBuffer.setLength(0);
 				}
 				for (final Position pos : slotPositions) {
 					insertRoxygen(content, pos, tags);
 				}
 			}

 			data.finishPostEdit();
 			return data;
 		}
 		catch (final Exception e) {
 			throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
 					TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
 		}
 	}

 	/**
 	 * Generates content for the Roxygen comment for the given method definition
 	 * @param rMethod function element
 	 * @param lineDelimiter the line delimiter to be used
 	 * @return
 	 * @throws CoreException thrown when the evaluation of the code template fails
 	 */
 	public static EvaluatedTemplate getMethodRoxygenComment(final RLangMethod rMethod, final String lineDelimiter) throws CoreException {
 		final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
 				.findTemplate(RCodeTemplateContextType.ROXYGEN_S4METHOD_TEMPLATE_ID);
 		if (template == null) {
 			return null;
 		}

 		final SourceUnit su = rMethod.getSourceUnit();
 		final RCodeTemplateContext context = new RCodeTemplateContext(
 				RCodeTemplateContextType.ROXYGEN_METHOD_CONTEXTTYPE, su, lineDelimiter);
 		context.setRElement(rMethod);

 		try {
 			final TemplateBuffer buffer = context.evaluate(template);
 			if (buffer == null) {
 				return null;
 			}
 			final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

 			final AbstractDocument content = data.startPostEdit();
 			final StringBuilder sb = new StringBuilder(64);

 			final Position[] sigPositions;
 			String sigText = null;
 			{	final TemplateVariable variable = TemplateUtils.findVariable(buffer,
 						RCodeTemplateContextType.ROXYGEN_SIG_LIST_VAR_NAME );
 				sigPositions = new Position[(variable != null) ? variable.getOffsets().length : 0];
 				for (int i = 0; i < sigPositions.length; i++) {
 					sigPositions[i] = new Position(variable.getOffsets()[i], variable.getLength());
 					content.addPosition(sigPositions[i]);
 				}

 				if (sigPositions.length > 0) {
 					final var parameters= rMethod.getParameters();
 					if (parameters != null) {
 						final int count = parameters.size();
 						for (int i = 0; i < count; i++) {
 							final var className= parameters.get(i).getClassName();
 							if (className == null || className.equals("ANY")) { //$NON-NLS-1$
 								break;
 							}
 							sb.append(className);
 							sb.append(","); //$NON-NLS-1$
 						}
 						if (sb.length() > 0) {
 							sigText = sb.substring(0, sb.length()-1);
 							sb.setLength(0);
 						}
 					}
 				}
 			}
 			final Position[] paramPositions;
 			String[] paramTags = null;
 			{	final TemplateVariable variable = TemplateUtils.findVariable(buffer,
 						RCodeTemplateContextType.ROXYGEN_PARAM_TAGS_VAR_NAME );
 				paramPositions = new Position[(variable != null) ? variable.getOffsets().length : 0];
 				for (int i = 0; i < paramPositions.length; i++) {
 					paramPositions[i] = new Position(variable.getOffsets()[i], variable.getLength());
 					content.addPosition(paramPositions[i]);
 				}

 				if (paramPositions.length > 0) {
 					final var parameters= rMethod.getParameters();
 					if (parameters != null) {
 						final int count = parameters.size();
 						paramTags = new String[count];
 						for (int i = 0; i < count; i++) {
 							final String paramName= parameters.get(i).getName();
 							sb.append("@param "); //$NON-NLS-1$
 							if (paramName != null) {
 								sb.append(paramName);
 							}
 							sb.append(" "); //$NON-NLS-1$
 							paramTags[i] = sb.toString();
 							sb.setLength(0);
 						}
 					}
 				}
 			}

 			for (final Position pos : sigPositions) {
 				insertRoxygen(content, pos, sigText);
 			}
 			for (final Position pos : paramPositions) {
 				insertRoxygen(content, pos, paramTags);
 			}

 			data.finishPostEdit();
 			return data;
 		}
 		catch (final Exception e) {
 			throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
 					TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
 		}
 	}

 	/**
 	 * Generates initial content for a new Rd file.
 	 *
 	 * @param su the Rd source unit to create the source for. The unit does not need to exist
 	 * @param lineDelimiter the line delimiter to be used
 	 * @return the new content or <code>null</code> if the template is undefined or empty
 	 * @throws CoreException thrown when the evaluation of the code template fails
 	 */
 	public static EvaluatedTemplate getNewRdFileContent(final BasicRResourceSourceUnit su, final String lineDelimiter) throws CoreException {
 		final Template template = RUIPlugin.getInstance().getRdCodeGenerationTemplateStore().findTemplate(RdCodeTemplateContextType.NEW_RDOCFILE);
 		if (template == null) {
 			return null;
 		}

 		final RdCodeTemplateContext context = new RdCodeTemplateContext(
 				RdCodeTemplateContextType.NEW_RDOCFILE_CONTEXTTYPE, su, lineDelimiter);

 		try {
 			final TemplateBuffer buffer = context.evaluate(template);
 			if (buffer == null) {
 				return null;
 			}
 			return new TemplateUtils.EvaluatedTemplate(buffer, lineDelimiter);
 		}
 		catch (final Exception e) {
 			throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
 					TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
 		}
 	}

 	private static void insertRoxygen(final AbstractDocument doc, final Position pos, final String[] tags) throws BadLocationException {
 		final int line = doc.getLineOfOffset(pos.getOffset());
 		final int lineOffset = doc.getLineOffset(line);
 		final int lineLength = doc.getLineLength(line);

 		final String orgLine = doc.get(lineOffset, lineLength);
 		final String prefix = orgLine.substring(0, pos.getOffset()-lineOffset); // can be replaced by more intelligent search
 		if (tags == null) {
 			return;
 		}
 		if (tags.length == 0) {
 			if (onlyWhitespace(orgLine.substring(prefix.length(), pos.getOffset()-lineOffset))
 					&& onlyWhitespace(orgLine.substring(pos.getOffset()-lineOffset+pos.getLength()))) {
 				doc.replace(lineOffset, lineLength, ""); //$NON-NLS-1$
 				return;
 			}
 			else {
 				doc.replace(pos.getOffset(), pos.getLength(), ""); //$NON-NLS-1$
 				return;
 			}
 		}
 		final StringBuilder sb = new StringBuilder(tags.length * 16);
 		sb.append(tags[0]);
 		for (int i = 1; i < tags.length; i++) {
 			sb.append(doc.getDefaultLineDelimiter());
 			sb.append(prefix);
 			sb.append(tags[i]);
 		}
 		doc.replace(pos.getOffset(), pos.getLength(), sb.toString());
 	}

 	private static void insertRoxygen(final AbstractDocument doc, final Position pos, final String s) throws BadLocationException {
 		doc.replace(pos.getOffset(), pos.getLength(), (s != null) ? s : ""); //$NON-NLS-1$
 	}

 	private static boolean onlyWhitespace(final String s) {
 		for (int i = 0; i < s.length(); i++) {
 			final char c = s.charAt(0);
 			if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
 				return false;
 			}
 		}
 		return true;
 	}


 	private CodeGeneration() {}

 }
	/*=============================================================================#
	# Copyright (c) 2005, 2021 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.r.codegeneration;

	import java.util.List;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.text.AbstractDocument;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.templates.Template;
	import org.eclipse.jface.text.templates.TemplateBuffer;
	import org.eclipse.jface.text.templates.TemplateVariable;
	import org.eclipse.osgi.util.NLS;

	import org.eclipse.statet.ecommons.templates.TemplateMessages;

	import org.eclipse.statet.internal.r.ui.RUIPlugin;
	import org.eclipse.statet.ltk.model.core.element.LtkModelElement;
	import org.eclipse.statet.ltk.model.core.element.SourceUnit;
	import org.eclipse.statet.ltk.ui.templates.TemplateUtils;
	import org.eclipse.statet.ltk.ui.templates.TemplateUtils.EvaluatedTemplate;
	import org.eclipse.statet.r.core.BasicRResourceSourceUnit;
	import org.eclipse.statet.r.core.rmodel.RElement;
	import org.eclipse.statet.r.core.rmodel.RLangClass;
	import org.eclipse.statet.r.core.rmodel.RLangMethod;
	import org.eclipse.statet.r.core.rmodel.RLangSlot;
	import org.eclipse.statet.r.core.rmodel.RSourceUnit;
	import org.eclipse.statet.r.ui.RUI;


	/**
	* Class that offers access to the code templates contained.
	*/
	public class CodeGeneration {


	/**
	* Generates initial content for a new R script file.
	*
	* @param su the R source unit to create the source for. The unit does not need to exist
	* @param lineDelimiter the line delimiter to be used
	* @return the new content or <code>null</code> if the template is undefined or empty
	* @throws CoreException thrown when the evaluation of the code template fails
	*/
	public static EvaluatedTemplate getNewRFileContent(final RSourceUnit su, final String lineDelimiter) throws CoreException {
	final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore().findTemplate(RCodeTemplateContextType.NEW_RSCRIPTFILE);
	if (template == null) {
	return null;
	}

	final RCodeTemplateContext context = new RCodeTemplateContext(
	RCodeTemplateContextType.NEW_RSCRIPTFILE_CONTEXTTYPE, su, lineDelimiter);

	try {
	final TemplateBuffer buffer = context.evaluate(template);
	if (buffer == null) {
	return null;
	}
	return new TemplateUtils.EvaluatedTemplate(buffer, lineDelimiter);
	}
	catch (final Exception e) {
	throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
	TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
	}
	}

	/**
	* Generates content for the Roxygen comment for the given function definition
	* @param rMethod function element
	* @param lineDelimiter the line delimiter to be used
	* @return
	* @throws CoreException thrown when the evaluation of the code template fails
	*/
	public static EvaluatedTemplate getCommonFunctionRoxygenComment(final RLangMethod rMethod, final String lineDelimiter) throws CoreException {
	final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
	.findTemplate(RCodeTemplateContextType.ROXYGEN_COMMONFUNCTION_TEMPLATE_ID);
	if (template == null) {
	return null;
	}

	final SourceUnit su = rMethod.getSourceUnit();
	final RCodeTemplateContext context = new RCodeTemplateContext(
	RCodeTemplateContextType.ROXYGEN_COMMONFUNCTION_CONTEXTTYPE, su, lineDelimiter);
	context.setRElement(rMethod);

	try {
	final TemplateBuffer buffer = context.evaluate(template);
	if (buffer == null) {
	return null;
	}
	final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

	final AbstractDocument content = data.startPostEdit();
	final StringBuilder tagBuffer = new StringBuilder(64);
	final TemplateVariable paramVariable = TemplateUtils.findVariable(buffer,
	RCodeTemplateContextType.ROXYGEN_PARAM_TAGS_VAR_NAME );
	final Position[] paramPositions = new Position[(paramVariable != null) ? paramVariable.getOffsets().length : 0];
	for (int i = 0; i < paramPositions.length; i++) {
	paramPositions[i] = new Position(paramVariable.getOffsets()[i], paramVariable.getLength());
	content.addPosition(paramPositions[i]);
	}

	if (paramPositions.length > 0) {
	String[] tags = null;
	final var parameters= rMethod.getParameters();
	if (parameters != null) {
	final int count = parameters.size();
	tags = new String[count];
	for (int i = 0; i < count; i++) {
	final String paramName= parameters.get(i).getName();
	tagBuffer.append("@param "); //$NON-NLS-1$
	if (paramName != null) {
	tagBuffer.append(paramName);
	}
	tagBuffer.append(" "); //$NON-NLS-1$
	tags[i] = tagBuffer.toString();
	tagBuffer.setLength(0);
	}
	}
	for (final Position pos : paramPositions) {
	insertRoxygen(content, pos, tags);
	}
	}

	data.finishPostEdit();
	return data;
	}
	catch (final Exception e) {
	throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
	TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
	}
	}

	/**
	* Generates content for the Roxygen comment for the given class definition
	* @param rClass class element
	* @param lineDelimiter the line delimiter to be used
	* @return
	* @throws CoreException thrown when the evaluation of the code template fails
	*/
	public static EvaluatedTemplate getClassRoxygenComment(final RLangClass rClass, final String lineDelimiter) throws CoreException {
	final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
	.findTemplate(RCodeTemplateContextType.ROXYGEN_S4CLASS_TEMPLATE_ID);
	if (template == null) {
	return null;
	}

	final SourceUnit su = rClass.getSourceUnit();
	final RCodeTemplateContext context = new RCodeTemplateContext(
	RCodeTemplateContextType.ROXYGEN_CLASS_CONTEXTTYPE, su, lineDelimiter);
	context.setRElement(rClass);

	try {
	final TemplateBuffer buffer = context.evaluate(template);
	if (buffer == null) {
	return null;
	}
	final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

	final AbstractDocument content = data.startPostEdit();
	final StringBuilder tagBuffer = new StringBuilder(64);
	final TemplateVariable slotVariable = TemplateUtils.findVariable(buffer,
	RCodeTemplateContextType.ROXYGEN_SLOT_TAGS_VAR_NAME );
	final Position[] slotPositions = new Position[(slotVariable != null) ? slotVariable.getOffsets().length : 0];
	for (int i = 0; i < slotPositions.length; i++) {
	slotPositions[i] = new Position(slotVariable.getOffsets()[i], slotVariable.getLength());
	content.addPosition(slotPositions[i]);
	}

	if (slotPositions.length > 0) {
	final List<? extends LtkModelElement> slots = rClass.getModelChildren(RElement.R_S4SLOT_FILTER);
	final int count = slots.size();
	final var tags= new String[count];
	for (int i = 0; i < count; i++) {
	final RLangSlot slot = (RLangSlot)slots.get(i);
	tagBuffer.append("@slot "); //$NON-NLS-1$
	tagBuffer.append(slot.getElementName().getDisplayName());
	tagBuffer.append(" "); //$NON-NLS-1$
	tags[i] = tagBuffer.toString();
	tagBuffer.setLength(0);
	}
	for (final Position pos : slotPositions) {
	insertRoxygen(content, pos, tags);
	}
	}

	data.finishPostEdit();
	return data;
	}
	catch (final Exception e) {
	throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
	TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
	}
	}

	/**
	* Generates content for the Roxygen comment for the given method definition
	* @param rMethod function element
	* @param lineDelimiter the line delimiter to be used
	* @return
	* @throws CoreException thrown when the evaluation of the code template fails
	*/
	public static EvaluatedTemplate getMethodRoxygenComment(final RLangMethod rMethod, final String lineDelimiter) throws CoreException {
	final Template template = RUIPlugin.getInstance().getRCodeGenerationTemplateStore()
	.findTemplate(RCodeTemplateContextType.ROXYGEN_S4METHOD_TEMPLATE_ID);
	if (template == null) {
	return null;
	}

	final SourceUnit su = rMethod.getSourceUnit();
	final RCodeTemplateContext context = new RCodeTemplateContext(
	RCodeTemplateContextType.ROXYGEN_METHOD_CONTEXTTYPE, su, lineDelimiter);
	context.setRElement(rMethod);

	try {
	final TemplateBuffer buffer = context.evaluate(template);
	if (buffer == null) {
	return null;
	}
	final EvaluatedTemplate data = new EvaluatedTemplate(buffer, lineDelimiter);

	final AbstractDocument content = data.startPostEdit();
	final StringBuilder sb = new StringBuilder(64);

	final Position[] sigPositions;
	String sigText = null;
	{ final TemplateVariable variable = TemplateUtils.findVariable(buffer,
	RCodeTemplateContextType.ROXYGEN_SIG_LIST_VAR_NAME );
	sigPositions = new Position[(variable != null) ? variable.getOffsets().length : 0];
	for (int i = 0; i < sigPositions.length; i++) {
	sigPositions[i] = new Position(variable.getOffsets()[i], variable.getLength());
	content.addPosition(sigPositions[i]);
	}

	if (sigPositions.length > 0) {
	final var parameters= rMethod.getParameters();
	if (parameters != null) {
	final int count = parameters.size();
	for (int i = 0; i < count; i++) {
	final var className= parameters.get(i).getClassName();
	if (className == null \|\| className.equals("ANY")) { //$NON-NLS-1$
	break;
	}
	sb.append(className);
	sb.append(","); //$NON-NLS-1$
	}
	if (sb.length() > 0) {
	sigText = sb.substring(0, sb.length()-1);
	sb.setLength(0);
	}
	}
	}
	}
	final Position[] paramPositions;
	String[] paramTags = null;
	{ final TemplateVariable variable = TemplateUtils.findVariable(buffer,
	RCodeTemplateContextType.ROXYGEN_PARAM_TAGS_VAR_NAME );
	paramPositions = new Position[(variable != null) ? variable.getOffsets().length : 0];
	for (int i = 0; i < paramPositions.length; i++) {
	paramPositions[i] = new Position(variable.getOffsets()[i], variable.getLength());
	content.addPosition(paramPositions[i]);
	}

	if (paramPositions.length > 0) {
	final var parameters= rMethod.getParameters();
	if (parameters != null) {
	final int count = parameters.size();
	paramTags = new String[count];
	for (int i = 0; i < count; i++) {
	final String paramName= parameters.get(i).getName();
	sb.append("@param "); //$NON-NLS-1$
	if (paramName != null) {
	sb.append(paramName);
	}
	sb.append(" "); //$NON-NLS-1$
	paramTags[i] = sb.toString();
	sb.setLength(0);
	}
	}
	}
	}

	for (final Position pos : sigPositions) {
	insertRoxygen(content, pos, sigText);
	}
	for (final Position pos : paramPositions) {
	insertRoxygen(content, pos, paramTags);
	}

	data.finishPostEdit();
	return data;
	}
	catch (final Exception e) {
	throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
	TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
	}
	}

	/**
	* Generates initial content for a new Rd file.
	*
	* @param su the Rd source unit to create the source for. The unit does not need to exist
	* @param lineDelimiter the line delimiter to be used
	* @return the new content or <code>null</code> if the template is undefined or empty
	* @throws CoreException thrown when the evaluation of the code template fails
	*/
	public static EvaluatedTemplate getNewRdFileContent(final BasicRResourceSourceUnit su, final String lineDelimiter) throws CoreException {
	final Template template = RUIPlugin.getInstance().getRdCodeGenerationTemplateStore().findTemplate(RdCodeTemplateContextType.NEW_RDOCFILE);
	if (template == null) {
	return null;
	}

	final RdCodeTemplateContext context = new RdCodeTemplateContext(
	RdCodeTemplateContextType.NEW_RDOCFILE_CONTEXTTYPE, su, lineDelimiter);

	try {
	final TemplateBuffer buffer = context.evaluate(template);
	if (buffer == null) {
	return null;
	}
	return new TemplateUtils.EvaluatedTemplate(buffer, lineDelimiter);
	}
	catch (final Exception e) {
	throw new CoreException(new Status(IStatus.ERROR, RUI.BUNDLE_ID, NLS.bind(
	TemplateMessages.TemplateEvaluation_error_description, template.getDescription()), e));
	}
	}

	private static void insertRoxygen(final AbstractDocument doc, final Position pos, final String[] tags) throws BadLocationException {
	final int line = doc.getLineOfOffset(pos.getOffset());
	final int lineOffset = doc.getLineOffset(line);
	final int lineLength = doc.getLineLength(line);

	final String orgLine = doc.get(lineOffset, lineLength);
	final String prefix = orgLine.substring(0, pos.getOffset()-lineOffset); // can be replaced by more intelligent search
	if (tags == null) {
	return;
	}
	if (tags.length == 0) {
	if (onlyWhitespace(orgLine.substring(prefix.length(), pos.getOffset()-lineOffset))
	&& onlyWhitespace(orgLine.substring(pos.getOffset()-lineOffset+pos.getLength()))) {
	doc.replace(lineOffset, lineLength, ""); //$NON-NLS-1$
	return;
	}
	else {
	doc.replace(pos.getOffset(), pos.getLength(), ""); //$NON-NLS-1$
	return;
	}
	}
	final StringBuilder sb = new StringBuilder(tags.length * 16);
	sb.append(tags[0]);
	for (int i = 1; i < tags.length; i++) {
	sb.append(doc.getDefaultLineDelimiter());
	sb.append(prefix);
	sb.append(tags[i]);
	}
	doc.replace(pos.getOffset(), pos.getLength(), sb.toString());
	}

	private static void insertRoxygen(final AbstractDocument doc, final Position pos, final String s) throws BadLocationException {
	doc.replace(pos.getOffset(), pos.getLength(), (s != null) ? s : ""); //$NON-NLS-1$
	}

	private static boolean onlyWhitespace(final String s) {
	for (int i = 0; i < s.length(); i++) {
	final char c = s.charAt(0);
	if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
	return false;
	}
	}
	return true;
	}


	private CodeGeneration() {}

	}