don't limit yourself to `it` ident about iterrr

[hamidb80]

i can define a untyped template or really do the unpacking

[hamidb80]

I didn't use template for that. that was a very bad idea.

here's what I did instead:

imap[a,b,c](a + b * c - 12)

[a,b,c] => [(0. a), (1, b), (2,c) ]
a + b * c - 12  => it[0] + it[1] * it[2] - 1

I replaced the the idents directly in the parameter of entity with their corresponding index.