In the below, why does the eval fail but the value works?
Also, what exactly is the k){x'y} part of the parse output and why did I have to enclose it in quotes for the value statement to work?

q)colist: `a`b`c

q){(=;x;0)} each colist
= `a 0
= `b 0
= `c 0

q)parse "{(=;x;0)} each colist"
k){x'y}
{(=;x;0)}
`colist

q)eval ("k){x'y}"; {(=;x;0)}; colist)
'c
  [0]  eval ("k){x'y}"; {(=;x;0)}; colist)
       ^

q)value ("k){x'y}"; {(=;x;0)}; colist)
= `a 0
= `b 0
= `c 0