public object visitExprLogicalExpr(ExprLogical expr)
{
object left = evaluate(expr.left);
switch (expr.eOperator.type)
{
case TokenType.OR:
if (isTruthy(left))
{
return(left);
}
break;
case TokenType.AND:
if (!isTruthy(left))
{
return(left);
}
break;
case TokenType.QMARK:
if (!isTruthy(left))
{
return(null);
}
break;
}
return(evaluate(expr.right));
}
private Expr ternaryConditionalExpr()
{
if (match(TokenType.QMARK))
{
Token operatorExpr = previous();
Expr right = assignmentExpr();
if (match(TokenType.COLON))
{
right = assignmentExpr();
}
throw error(operatorExpr, "Expected expression before '" + operatorExpr.lexeme + "'.");
}
Expr expr = assignmentExpr();
if (match(TokenType.QMARK))
{
Token operatorExpr1 = previous();
Expr leftExpr = assignmentExpr();
if (match(TokenType.COLON))
{
Token operatorExpr2 = previous();
Expr rightExpr = assignmentExpr();
expr = new ExprTernary(expr, operatorExpr1, leftExpr, operatorExpr2, rightExpr);
}
else
{
expr = new ExprLogical(expr, operatorExpr1, leftExpr);
}
}
return(expr);
}
Expr logicAndExpr()
{
if (match(TokenType.AND))
{
Token operatorExpr = previous();
Expr right = equalityExpr();
throw error(operatorExpr, "Expected expression before '" + operatorExpr.lexeme + "'.");
}
Expr expr = equalityExpr();
while (match(TokenType.AND))
{
Token op = previous();
Expr right = equalityExpr();
expr = new ExprLogical(expr, op, right);
}
return(expr);
}
public object visitExprLogicalExpr(ExprLogical expr)
{
resolve(expr.left);
resolve(expr.right);
return(null);
}
public object visitExprLogicalExpr(ExprLogical expr)
{
return(parenthesize(expr.eOperator.lexeme, expr.left, expr.right));
}