From: Gavin Kistner <gavin@...>
Date: 2005-02-22T23:37:37+09:00
Subject: Re: Proposal for nil, 0, and "" in an if statement

On Feb 22, 2005, at 7:32 AM, Gavin Kistner wrote:

> On Feb 22, 2005, at 7:19 AM, Peter Hickman wrote:
>>> I don't have actual code, but imagine looping through records 
>>> returned with financial data, and you want to print out a "-" if the 
>>> field is missing -or- zero. The whole "this field doesn't have any 
>>> meaningful information that contributes to the sum of the column" 
>>> spreadsheet thing.
>>>
>> Might this not cause trouble with databases. A database record 
>> (returned
>> as a structure or object) would have NULL == nil for fields with no
>> value which is not the same as a field with a definite value such as 
>> 0.
>
> Yes, there are many cases where you DO want to distinguish between nil 
> and 0. These cases are already handled by the current behavior of 
> Ruby.

To be clear - the proposal is NOT to make Ruby act like one of the many 
other languages where "", 0 and friends are treated as non-truth values 
in boolean expressions. The proposal is simply to add an additional 
method to all that allows a programmer to treat them the same in the 
few cases where that is desirable.