atomo-0.2: prelude/association.atomo

operator right 1 ->

Association = Object clone
a -> b := Association clone do: { from = a; to = b }

(a: Association) show :=
    a from show .. " -> " .. a to show

[] lookup: _ = @none
(a . as) lookup: k :=
  if: (k == a from)
    then: { @(ok: a to) }
    else: { as lookup: k }

[] find: _ = @none
(a . as) find: k :=
  if: (k == a from)
    then: { @(ok: a) }
    else: { as find: k }

[] set: k to: v := [k -> v]
(a . as) set: k to: v :=
  if: (k == a from)
    then: { (k -> v) . as }
    else: { a . (as set: k to: v) }