Class BSHWhileStatement

src/bsh/BSHWhileStatement.java:31–87

This class handles both while statements and do..while statements.

 * This class handles both {@code while} statements and {@code do..while} statements.
*/
class BSHWhileStatement extends SimpleNode implements ParserConstants {

	/**
	 * Set by Parser, default {@code false}
	 */
	boolean isDoStatement;

    BSHWhileStatement(int id) {
		super(id);
	}


    public Object eval( CallStack callstack, Interpreter interpreter) throws EvalError {
		int numChild = jjtGetNumChildren();

		// Order of body and condition is swapped for do / while
        final SimpleNode condExp;
		final SimpleNode body;

		if ( isDoStatement ) {
			condExp = (SimpleNode) jjtGetChild(1);
			body = (SimpleNode) jjtGetChild(0);
		} else {
			condExp = (SimpleNode) jjtGetChild(0);
			if ( numChild > 1 )	{
				body = (SimpleNode) jjtGetChild(1);
			} else {
				body = null;
			}
		}

		boolean doOnceFlag = isDoStatement;

        while (doOnceFlag || BSHIfStatement.evaluateCondition(condExp, callstack, interpreter)) {
			doOnceFlag = false;
			// no body?
			if ( body == null ) {
				continue;
			}
			Object ret = body.eval(callstack, interpreter);
			if (ret instanceof ReturnControl) {
				switch(( (ReturnControl)ret).kind ) {
					case RETURN:
						return ret;

					case CONTINUE:
						break;

					case BREAK:
						return Primitive.VOID;
				}
			}
		}
        return Primitive.VOID;
    }

}