Here's a version that doesn't use a lambda. Instead, there's a new function `findl' that captures `list' from its caller (`finds').
∇z←list find key z←key≡¨list ∇ ∇z←findl key z←(nl list) find ⊂key ∇ ∇z←list finds keys z←findl¨nl keys ∇ ∇z←me e z←⊂(⎕io+≡e)⊃(⊂,e) (,e) (e) ∇ ∇z←nl l z←me¨(⎕io+1=≡l)⊃l (⊂l) ∇ On Fri, 2014-05-09 at 12:55 -0700, David B. Lamkins wrote: [snip] > Here's an example: > > ]boxing 8 > ll←'a' 'bc' 'def' 'foo' 'g' > ll > ┌→───────────────────┐ > │a ┌→─┐ ┌→──┐ ┌→──┐ g│ > │ │bc│ │def│ │foo│ │ > │ └──┘ └───┘ └───┘ │ > └∊───────────────────┘ > ll finds 'a' > ┌───────────┐ > │┌→────────┐│ > ││1 0 0 0 0││ > │└─────────┘│ > └∊──────────┘ > ll finds 'bc' 'foo' > ┌→──────────────────────┐ > │┌→────────┐ ┌→────────┐│ > ││0 1 0 0 0│ │0 0 0 1 0││ > │└─────────┘ └─────────┘│ > └∊──────────────────────┘ > ⍝ Beware... > ll finds 'a' 'g' > ┌───────────┐ > │┌→────────┐│ > ││0 0 0 0 0││ > │└─────────┘│ > └∊──────────┘ > ⍝ ... because: > 'a' 'g' > ┌→─┐ > │ag│ > └──┘ > ll finds (,'a') (,'g') > ┌→──────────────────────┐ > │┌→────────┐ ┌→────────┐│ > ││1 0 0 0 0│ │0 0 0 0 1││ > │└─────────┘ └─────────┘│ > └∊──────────────────────┘ >
