//
// various attempts to figure out how head/tail-recursion might work in OMeta:
//

ometa List {
  joinJS anything*:i -> (i.join('; ') + '***JS'),

  join1 end -> '***end',
  join1 :h join1:t -> (h.toString() + "; " + t),

  join2 :h end     -> (h.toString() + "***end"),
  join2 :h join2:t -> (h.toString() + "; " + t),

  join3 end        -> "***not end",
  join3 :h end     -> (h.toString() + "***end"),
  join3 :h join3:t -> (h.toString() + "; " + t),

  list end         -> [],
  list :h list:t   -> [h].concat(t),

  list2 list2:h anything:t -> h.concat(t),
  list2 end        -> [],

  end_marker
}

// here is a JavaScript reference for join that works :-)
List.matchAll( [1,2,3], "joinJS" )  1; 2; 3***JS
List.matchAll( [1], "joinJS" )      1***JS
List.matchAll( [], "joinJS" )       ***JS

// this one adds '; ' after last element :-(
List.matchAll( [1,2,3], "join1" )   1; 2; 3; ***end
List.matchAll( [1], "join1" )       1; ***end
List.matchAll( [], "join1" )        ***end

// not good either :-(
List.matchAll( [1,2,3], "join2" )   1; 2; 3***end
List.matchAll( [], "join2" )        (match fails)

// here is n OMeta join that works :-)
List.matchAll( [1,2,3], "join3" )   1; 2; 3***end
List.matchAll( [1], "join3" )       1***end
List.matchAll( [], "join3" )        ***not end

// an OMeta list w. head and tail that works:
List.matchAll( [1,2,3], "list" )    [1, 2, 3]
List.matchAll( [1], "list" )        [1]
List.matchAll( [], "list" )         []

// trying a left-recursive implementation - did not work :-(
List.matchAll( [1,2,3], "list2" )    (match fails)
List.matchAll( [1], "list2" )        (match fails)
List.matchAll( [], "list2" )        []