what is the assignment expression return value?

I believe in C, an assignment expression returns the value of the left
side of the assignment. For example, a = 2, would return 2.

If this is true, is Skill similar? For instance, if I have the
following, a = nil, would it return nil ?

 

It seems like it would return nil but for different reason than C. I
believe it returns the value of the expression on the right side that
happens to be what is assigned to a.

 

Dear vlsidesign,

Why don't you give it a try into your CIW ? you will get the truth by
yourself ;-)
I guess you don't have cadence.

Give a look at the function 'setq' in the following document :
Cadence SKILL Language Reference ($CDSHOME/doc/sklangref.pdf).
As you can see in this document setq is the same as the assignment (=)
operator. It sets a variable to a new value and returns this new value
(or the evaluated result if the assigned new value is an expression).
I think that (=) is internally translated to setq (to be confirmed or
not by the skill experts).

ciw> x = 5
=> 5
ciw> (setq x 5)
=> 5
ciw> a = nil
=> nil

Do mind that nil is a special atom in skill !

Hope it helps !

Riad.

 

Yes it is, it returns the value of the expression on the right side.

 

vlsidesign wrote, on 05/14/08 22:55:

The assignment operator is converted into functional equivalent, by working
from right to left. Most operators work left to right:

(setq a
(setq b
(setq c
(setq d 5)
)
)
)

The above shows you the functional equivalent (i.e. how it is actually implemented)
for a=b=c=d=5. So you can see precedence and left-to-right/right-to-left handling
by looking at the output of that.

So it behaves just like C in this respect - the compiler expands = operators right to left.

Regards,

Andrew.