SKILL Q: Coaxing a Symbol to Give Up Its Value Without Usin

[Edward]

Anyone who has glanced at the Cadence SKILL documentation knows the
use of eval() is a no-no. But there are situations in which one binds
a value to a symbol and then passes the QUOTED symbol around before
finally needing the actual value associated with the symbol. What
other ways can one get at a symbol's value besides using eval()?

 

[S. Badel]

Anyone who has glanced at the Cadence SKILL documentation knows the
use of eval() is a no-no. But there are situations in which one binds
a value to a symbol and then passes the QUOTED symbol around before
finally needing the actual value associated with the symbol. What
other ways can one get at a symbol's value besides using eval()?

symeval() does precisely this. But I don't think the end result is any different from using eval().

I do not see any problems with eval() myself, though.

Cheers,
Stéphane

 

[Andrew Beckett]

S. Badel wrote, on 04/17/08 00:05:

Anyone who has glanced at the Cadence SKILL documentation knows the
use of eval() is a no-no. But there are situations in which one binds
a value to a symbol and then passes the QUOTED symbol around before
finally needing the actual value associated with the symbol. What
other ways can one get at a symbol's value besides using eval()?

symeval() does precisely this. But I don't think the end result is any
different from using eval().

I do not see any problems with eval() myself, though.

Cheers,
Stéphane

It's preferrable to avoid eval() because:

a) it means you're doing run-time evaluation - this means you're not taking
advantage of the byte-code compilation which will improve speed
b) you need to be particularly careful when using SKILL++ code because
of it needing to understand the scope you're in.

symeval() to some extent is similar, but it's really just looking up a
symbol value, so that's not so costly.

However, often you'd be better off using a macro.

See my previous posting http://tinyurl.com/5wx3y7

Andrew.