Redundancies often reveal bugs

[Stewart Gordon]

On 01/10/2010 02:12, bearophile wrote:
<snip>
>> Researchers at Stanford have just released a paper detailing their use of automated tools
> to look for redundant code in 1.6 million lines of Linux. "Redundant" is defined as:
> - Idempotent operations (like assigning a variable to itself)
<snip>

Idempotent operations are not necessarily redundant.

For example,

     x = y;

is idempotent, but not redundant.  But performing the same idempotent 
operation multiple times in succession is an example of redundancy.

Really, section 2 of that paper isn't about idempotence at all.

For those who aren't sure what idempotent means, put simply it means 
that performing the operation multiple times in succession has the same 
effect as performing it only once.

But assigning a variable to itself is indeed redundant, because it has 
no effect.

Stewart.