[OT] difference of Scripting and programming

[John Summerfied]

Jeff Vian wrote:
> On Mon, 2005-05-23 at 15:04 -0700, Ian Puleston wrote:
> 
>>>-----Original Message-----
>>>From: fedora-list-bounces at redhat.com [mailto:fedora-list-
>>>bounces at redhat.com] On Behalf Of Jeff Vian
>>>
>>>
>>>>When you write a C program, isn't the source code a "script of commands"
>>>>telling another program (the compiler), what to do?
>>>
>>>yes
>>
>>Nope, the compiler is simply a translator that translates the program into
>>terms that the computer understands. It's the computer that executes the
>>program, not the compiler.
>>
> 
> The same applies to an interpreter. It "interprets" the code (script)
> and provides the resulting machine understandable commands to the
> machine.

Not so. It's more accurate to regard the interpreter as implementing a 
virtual computer. One whose primitives are the instructions of the language.


> No, that is a misrepresentation.  The interpreter serves a function
> similar to the compiler.  It makes human readable text into machine
> understandable code. (run time compiled instead of precompiled)  The
> real difference is when the compiling is done, and how.  

Some interpreters (bot probably not most)  Pascal originally compiled to 
a form called pcode and then there was a program to interpret the pcode.

Java still does that (aside from the compilers that compile to machine 
code). Some JVMs implement a "just-in-time" compiler that does create 
machine instructions, but AFAIK that can be turned off and is optional.



-- 

Cheers
John

-- spambait
1aaaaaaa at computerdatasafe.com.au  Z1aaaaaaa at computerdatasafe.com.au
Tourist pics http://portgeographe.environmentaldisasters.cds.merseine.nu/