Announcing E 0.8.4: The Birthday Release
Mark S. Miller
Tue, 01 Jun 1999 14:28:51 -0700
>On Fri, 28 May 1999, Mark S. Miller wrote:
>> x |=| y
>> meaning that x and y are equivalent in their natural partial ordering.
>> This is a peer to <, <=, >=, and >. Think of 'x |=| y' as 'x <= y &&
>> x >= y'.
At 10:16 AM 5/28/99 , Ka-Ping Yee wrote:
>[#] How about <=> instead, to make more obvious their kinship?
>Pipe characters don't appear in any of the other operators in
>this family, and <=> is a clearer mnemonic for <= && =>.
[+] I originally rejected this for a bogus reason.
It was one of the alternatives I'd originally considered, but thinking back
I see that my reason for rejecting this was stupid. I remembered the old
Basic not equals operator, "<>", which means "less than *or* greater than".
Similarly, "<=" means "less than *or* equals", so I thought people would
assume "<=>" means "less than, equal to, or greater than", ie, comparable to.
Now that you've raised it, it's clear to me that people will instead assume
only that it's a comparison operator, but know they don't know what it means
until they find out. Once they do find out, it's easily memorable by its
place in the following sequence:
< <= <=> >= >
I will add this in 0.8.5, and deprecate |=|. In 0.8.6, I will remove |=|.