Actually that was one of my first questions here.

(EDIT found it: why does push not default to $_?)

My guess is that it's because it's taking multiple args via push @a, LIST , and not a single one push @a, EXPR °

> allowing code to be more concise, succinct, and economical.

Nah, that's not true, because the defaults in Perl are not orthogonal.

You have to check for every operator and built-in how it's implemented.

especially the scalar behavior is very diverse.

EDIT

°) While it's still technically possible, this might be logically to confusing.

And symmetry would require a void ;shift or ;pop to automatically set $_ , which would most certainly break things!