RE: set!

[Avi Kivity <Avi@xxxxxxxxxxxxx>]

On Tuesday, January 05, 1999 14:06, Stefan Mintert
[SMTP:mintert@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx] wrote:
> 
> 
> Hi!
> 
> 
> I'm looking for a way to *change* the value of a variable. Some
> years ago I
> learned Scheme based on the book "Structure and interpretation of
> computer
> programs" by Abelson/Sussman/Sussman. The Scheme version described
> in that
> book contains a function called set!. Does the expression language
> of DSSSL
> contain such a feature? 

No, but I've seen a proposal (can't remember where) to add some mutating
operations.

> 
> On page 30 of the DSSSL spec one can read: "The expression language
> uses only
> the functional, side-effect free subset of Scheme. [...]"
> 
> I guess that set! or any equivalent feature was removed because of
> it's
> side-effects. Is that correct?

Yes.

> 
> Any help is appreciated. Thanks in advance!
> 

Post your problem! Usually a side-effect-free solution can be found,
although it's not always elegant.

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