[racket] [OT] Re: Fundamentals

From: Neil Van Dyke (neil at neilvandyke.org)
Date: Sat Oct 16 12:29:40 EDT 2010

Jakub Piotr Cłapa wrote at 10/16/2010 11:57 AM:
> On 14.10.10 11:44, Noel Welsh wrote:
>> The distinction is a bit arbitrary, as with a one-to-one mapping you 
>> can convert from one to the other with no loss of information.
> AFAIK this is true in general since in the raw binary form you have to 
> distinguish code from data and as far as my knowledge od disassemblers 
> goes it is not a trivial problem to solve.

Just in case any student is confused: by "one-to-one", Noel was speaking 
of assembly language when it used as a target code of a compiler (note 
his "usually").  You might see assembly language code that uses macros 
and descriptive symbolic labels, which have information that is lost 
when assembling to its target machine (or virtual machine / p-code) 
code, especially if it is handwritten.  Plus, if the assembly language 
was handwritten, the comments are often indispensable, and they, too, 
are lost when going to target code.


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