> Right. So you're actually saying that (MessageSend receiver: 1
> selector: #abs) numArgs == 0 instead of the correct 1. I agree. Sorry
> for the noise!

I have trouble understanding the above.  0 is the correct answer for
that example, not 1, but this change has no bearing on that example.

> (Of course you could also ^ arguments size + 1...)

Mmm, no.  The idea here is that if a message selector Symbol such as
#at:put: has a numArgs of 2, and we create a MessageSend based on that
selector as in:

  MessageSend
     receiver: myDictionary
     selector: #at:put:

then its numArgs better be 2, not 0.

MessageSends are sometimes used interchangeably with Blocks:

   [ :key :value | myDictionary at: key put: value ]

because they're easier to serialize, but either one can be sent
#value:value: at some point in the future.

HTH.


> frank
>
>>> We have three proper constructors that create fully initialised
>>> MessageSends, so I'd rather hope (quite possibly in vain) that noone
>>> creates MessageSends through #new directly. It doesn't look like the
>>> base image does so.
>>
>