Faraday cages ( was Re: staticy plastic tubs )

[Chuck Guzis]

On 21 Oct 2006 at 10:07, Jay West wrote:

> You wrote...
> > In general I don't believe an interpreted language can beat a compiled 
> > language.  Interpreting tokens or keywords is just far slower than 
> > compiled code, unless the compiler is severely broken.  (Which I wouldn't 
> > call a fair comparison.)
> 
> In theory, you are right. In practice I believe you're making too much of a 
> generalization. 

It all depends on the language and the work to be performed.

Certainly, "tokenizing" can cut down on scanning time without 
affecting program readability, but that's more a form of input 
editing than compilation.

If the operations performed by the language are complex or time-
consuming, then the interpretation overhead is just a small portion 
of the overall execution time and doesn't matter very much.

For example, given the nature of operations in a language such as 
SNOBOL4, I wouldn't expect that the difference between interpretation 
and compilation would amount to much.

The point being that there's more to a compiler or interpreter than 
the symbol manipulation.  Clever run-time routines can make a huge 
difference.  Consider another common statement, "Native code is 
faster than P-code".  Maybe not...

Way back when in the 8-bit world, I was on a project to do a 
commercial BASIC.  We were given free reign of choices, from strict 
interpretation to compilation to native machine code. 

Given the operations that BASIC programs tended to perform (lots of 
floating-point math, string manipulation and I/O) and a requirement 
that the run-time be multi-user, we determined that compile-to-
machine-code had no special benefits and would actually be a 
detriment (hard to relocate dynamically and lengthy),  we used a 
incremental compile to a P-code and concentrated on making math and 
string operations very efficient.

The vindication came sometime later when we were showing our system 
at one of the trade shows (Comdex/  NCC? -- I don't remember) and 
Microsoft was demoing their brand-new compiled Basic-80.  A bunch of 
attendees decided to run benchmarks among the various BASICs.  We 
blew M$ out of the water--in spite of their compile-to-machine code 
approach, their string handling was dreadful.

We actually sold quite a few systems with multitasking (up to 5 way) 
on a single 3.5 MHz 8085 running the usual suite of small business 
apps, most of which were ported from the MCBA suite for a DG Nova.

Cheers,
Chuck