Re: : [ sisc-Bugs-1091312 ] java.lang.OutOfMemoryError: Java heap space

Ken Anderson wrote:

> To: "SourceForge.net" <[email protected]>
> Subject: Re: [SISC-devel] [ sisc-Bugs-1091312 ] java.lang.OutOfMemoryError: Java heap space
> Cc: [email protected]
> 
> The out of memory occurs because of how SICP does laziness.
> See http://srfi.schemers.org/srfi-45/srfi-45.html

Ken,

that's what I thought at first too but the problem turns out to be with 
the memo-proc procedure in the example. If it is changed to not remember 
the proc once it has been used, e.g.

(define (memo-proc proc)
   (let ((result #f))
     (lambda ()
       (if proc
           (begin (set! result (proc))
                  (set! proc #f)))
       result)))

then the code runs in near-constant space. SISC's general 
safe-for-spaceness may be one reason why that works - the compiler does 
capture analysis that guarantees that code does not hang on to 
references any longer than strictly necessary.


Matthias.



-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. 
http://productguide.itmanagersjournal.com/