On 28.12.2019, at 05:09, Mark Miller mmille10@comcast.net wrote:

I was trying to explain in a question on Smalltalk (on Quora.com) how messages are also objects, and I'm running into a bit of a problem in trying to demonstrate this in either Squeak or Pharo.

I started off using a simple example:

'5' asInteger --> 5

I can do the same thing with:

(Message selector: #asInteger) sendTo: '5' --> 5

This all works fine.

The response I got back from the person I was trying to convince was that since I'm using syntax to create and send a message (using sendTo: with a Message class), it's not really a message, because if a constructed message with Message is a message, then why use syntax to send "sendTo:" to it? He contends it's an object being used to represent a message. The actual message gets sent in the process of evaluation (I suppose he thinks the message is "unwrapped" from Message, and is sent under the covers).

I was going to try the following, to perhaps be more convincing (though I don't know if this is a lost cause re. convincing), but I ran into a problem. I tried translating the 2nd expression above into more explicit terms, and I'm running into an exception I can't explain. To me, what I'm doing is equivalent to the 2nd expression, but Smalltalk disagrees.

First version:

| m1 m2 | m1 := Message selector: #asInteger. m2 := Message selector: #sendTo argument: '5'. m2 sendTo: m1.

I also tried the following:

(Message selector: #sendTo argument: '5') sendTo: (Message selector: #asInteger)

In both cases, in both Squeak and Pharo, it throws up an exception saying:

"Message(Object)>>doesNotUnderstand: #sendTo" (Squeak)

or

"Instance of Message did not understand #sendTo" (Pharo).

The difference is the missing colon in the message.

Try

(Message selector: #sendTo: argument: '5') sendTo: (Message selector: #asInteger) instead of (Message selector: #sendTo argument: '5') sendTo: (Message selector: #asInteger)

Best regards -Tobias

This is bizarre to me, because if I look at Message in a browser, I can clearly see sendTo: is an instance method. Also, if it wasn't an instance method, then my very first example wouldn't have worked. I suspect I'm running into some underlying mechanics of how messages are sent, and how object state works in expressions.

Is this a bug? Am I missing something in how I'm using sendTo:? Or, does my experimentation reveal that I'm wrong about messages? :)

Thanks in advance for any clarity on this.

---Mark mmille10@comcast.net