What method for constracting an object is more efficient?

Question

I have a class that has several inner values:

private variable layer_type
private variable color
private variable name
private variable thickness
private variable conductivity
private variable permittivity
private variable loss_tangent

I want to initiate them with values that the user gives to the constructor, but since there 7 of them, to reduce clutter and code size I did it in a loop:

constructor {in_layer_type in_color in_conductivity in_loss_tangent in_name in_permittivity in_thikness f_row frame} {
    foreach var [list layer_type color conductivity loss_tangent name permittivity thikness] {
        set $var [set in_$var]
    }

Is there any difference (performance wise) with this approach, over the writing all the set commands?

set layer_type $in_layer_type
set color $in_color
#...
set thickness $in_thickness

How many microseconds are you interested in saving? Your real question should be: which is easier to read and maintain? — glenn jackman, Jan 02 '13 at 16:30
By `contractor`, did you mean `constructor`? And clatter=clutter? — Hai Vu, Jan 02 '13 at 16:31
@glennjackman, I realize that since it's only 7 the difference will be minor, but I'm still interested in the answer, to understand what is the more efficient practice. I have other pieces of code where I do similar things inside much longer loops. — SIMEL, Jan 02 '13 at 16:59

score 1 · Accepted Answer · answered Jan 02 '13 at 23:13

In strict terms of efficiency, writing it all out in full is the most efficient method. I suggest that you don't do that! The problem is that it's difficult to maintain and hard to use (I don't know about you, but I hate calls with lots of mandatory positional arguments in all languages!) Instead, try something like this:

constructor {f_row frame args} {
    foreach {var value} $args {
        if {[string match -* $var]} {
            set [string range $var 1 end] $value
        }
    }
    # ...
}

Yes, you need to write things a bit different to use this:

TheClass theObjToMake $theFRow $theFrame -layer_type 12345 ...

You're also advised to use Itcl's facilities for setting defaults if you're doing this. Pick something sensible and it will all suddenly seem very natural.

What method for constracting an object is more efficient?

1 Answers1