tcsh being dodgy, or pipe code ishoos?

[Artem 'Zazoobr' Ignatjev]

Juli Mallett wrote:
> Anyone with insight into this?
> 
> (jmallett at big-lizard:~)39% ( echo 1 ; ( ( echo 2 ; echo 3 ) | xargs -I% echo + % ) )
> 1
> + 2
> + 3
> (jmallett at big-lizard:~)40% ( echo 1 ; ( ( echo 2 ; echo 3 ) | xargs -I% echo + % ) ) | cat
> 1
> + +2
> 3
last cat is not necessary...
And it's more weird than that:
> ( echo 1 ; ( ( echo 2 ; echo 3 ) | xargs -I% echo -- + % ) )
1
-- --+  +2 
3