Dictionaries implementing using blocks and delicious metaprogramming.

dict.the.hs

(b: Block) key: (v: Object) := {
    find = { l |
        l match: {
            [] -> @nothing
            (e . es) ->
                if: (e values head evaluate == v)
                    then: { @(ok: (e values (at: 1) evaluate)) }
                    else: { find call: [es] }
        }
    }

    find call: [b contents]
} call

usage

> load: "prelude/dict.the" 
@ok
> { 0 -> 'a'; 1 -> 'b' } key: 0
@(ok: 'a')
> { 0 -> 'a'; 1 -> 'b' } key: 1
@(ok: 'b')
> { 0 -> 'a'; 1 -> 'b' } key: 42
@nothing
>