CodeIteratorWhile.java

/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2024, Arnaud Roques
 *
 * Project Info:  https://plantuml.com
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 * Original Author:  Arnaud Roques
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package net.sourceforge.plantuml.tim.iterator;

import java.util.List;

import net.sourceforge.plantuml.text.StringLocated;
import net.sourceforge.plantuml.text.TLineType;
import net.sourceforge.plantuml.tim.EaterException;
import net.sourceforge.plantuml.tim.EaterWhile;
import net.sourceforge.plantuml.tim.ExecutionContextWhile;
import net.sourceforge.plantuml.tim.TContext;
import net.sourceforge.plantuml.tim.TMemory;
import net.sourceforge.plantuml.tim.expression.TValue;
import net.sourceforge.plantuml.tim.expression.TokenStack;

public class CodeIteratorWhile extends AbstractCodeIterator {

	private final TContext context;
	private final TMemory memory;
	private final List<StringLocated> logs;

	public CodeIteratorWhile(CodeIterator source, TContext context, TMemory memory, List<StringLocated> logs) {
		super(source);
		this.context = context;
		this.memory = memory;
		this.logs = logs;
	}

	public StringLocated peek() throws EaterException {
		int level = 0;
		while (true) {
			final StringLocated result = source.peek();
			if (result == null)
				return null;

			final ExecutionContextWhile currentWhile = memory.peekWhile();
			if (currentWhile != null && currentWhile.isSkipMe()) {
				if (result.getType() == TLineType.WHILE) {
					level++;
				} else if (result.getType() == TLineType.ENDWHILE) {
					level--;
					if (level == -1) {
						memory.pollWhile();
						level = 0;
					}
				}
				next();
				continue;
			}

			if (result.getType() == TLineType.WHILE) {
				logs.add(result);
				executeWhile(memory, result.getTrimmed());
				next();
				continue;
			} else if (result.getType() == TLineType.ENDWHILE) {
				logs.add(result);
				if (currentWhile == null)
					throw new EaterException("No while related to this endwhile", result);

				final TValue value = currentWhile.conditionValue(result, context, memory);
				if (value.toBoolean())
					source.jumpToCodePosition(currentWhile.getStartWhile(), result);
				else
					memory.pollWhile();

				next();
				continue;
			}

			return result;
		}
	}

	private void executeWhile(TMemory memory, StringLocated s) throws EaterException {
		final EaterWhile condition = new EaterWhile(s);
		condition.analyze(context, memory);
		final TokenStack whileExpression = condition.getWhileExpression();
		final ExecutionContextWhile theWhile = ExecutionContextWhile.fromValue(whileExpression,
				source.getCodePosition());
		final TValue value = theWhile.conditionValue(s, context, memory);
		if (value.toBoolean() == false)
			theWhile.skipMe();

		memory.addWhile(theWhile);
	}

}