<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta content="text/html;charset=UTF-8" http-equiv="Content-Type"></head><body ><div style='font-size:10pt;font-family:Verdana,Arial,Helvetica,sans-serif;'>Eliot and Frank,<br><br>Thank you.<br><br><br><br><br><br><br><div id="1"><br>---- On Tue, 19 Nov 2013 08:47:00 -0800 <b>Eliot Miranda<eliot.miranda@gmail.com></b> wrote ---- <br></div><br><blockquote style="border-left: 1px solid #0000FF; padding-left: 6px; margin:0 0 0 5px"><div dir="ltr">Hi Timothy,<div><br><br><div>On Tue, Nov 19, 2013 at 8:33 AM, gettimothy <span dir="ltr"><<a subj="" mailid="gettimothy%40zoho.com" href="mailto:gettimothy@zoho.com" target="_blank">gettimothy@zoho.com</a>></span> wrote:<br> <blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u><div><div style="font-size:10pt;font-family:verdana,arial,helvetica,sans-serif">Part 4 of the Blue Book--chapter 26 The implementation--in the intro there is this example:<br> <br><br><br><blockquote style="border:1px solid rgb(204,204,204);padding:7px;background-color:rgb(245,245,245)"><div>center<br> ^ origin + corner / 2<br></div></blockquote> <br><br>With these operations<br><br><blockquote style="border:1px solid rgb(204,204,204);padding:7px;background-color:rgb(245,245,245)"> <div><br>Rectangle center<br> 0 push the value of the receiver's first instance variable (origin) onto the<br> stack<br> 1 push the value of the receiver's second instance variable (corner) onto the<br> stack<br> 176 send a binary message with the selector +<br> 119 push the Smalllnteger 2 onto the stack<br> 185 send a binary message with the selector /<br> 124 return the object on top of the stack as the value of the message (center)<br> </div></blockquote> <br>In a Workspace, when I doit on 3 + 7/2 I get 5, left, right, unary, binary....rules apply.<br><br>What I see here--and please check my reasoning--is a RPN that places things onto the stack via Smalltalk's order of operation rules and then does conventional RPN processing.<br> <br>In other words, Smalltalk expressions are translated to RPN and then placed on the stack.<br></div></div></blockquote><div><br></div><div>Yes, and so they are in most stack-based implementations of languages. Bytecode for a stack machine is a form of RPN.</div> <div><br></div><blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:10pt;font-family:verdana,arial,helvetica,sans-serif">A simple 'banish the thought' or 'yep' or 'sometimes' would be helpful as I move forward in my study. I am just trying to avoid carrying forward an improper idea that I will have to revise later when/if the facts turn out otherwise.<br> <br>thx.<br><br>t</div></div></blockquote></div><div><br></div>-- <br>best,<div>Eliot</div> </div></div> <br></blockquote><br></div></body></html>