tricu

A lazy functional language based on Tree Calculus
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microscope.tri (1095B)

      1 !import bd2c14d6db6b69308a5252a8e839705a55d30e815f012900b094315263e08d81 *
      2 !export shape
      3 !export size
      4 !export same
      5 
      6 -- Inspect data OR compiled program trees, not source text.
      7 -- Try shape (t t t), size (t t t), or same (t t) (t t).
      8 -- Also try shape (x : x): functions are inspectable trees too.
      9 -- triage dispatches directly on Leaf, Stem and Fork without visiting children.
     10 -- Arithmetic and Booleans come from base; traversal is the subject of this demo.
     11 shape tree = triage "Leaf" (child : "Stem") (left right : "Fork") tree
     12 
     13 -- Count every constructor occurrence, including repeated shared branches.
     14 -- This is expanded tree size, not allocated nodes or source-code length.
     15 countNodes tree acc = triage
     16   (succ acc)
     17   (child : countNodes child <| succ acc)
     18   (left right : succ acc |> countNodes left |> countNodes right)
     19   tree
     20 
     21 size tree = countNodes tree 0
     22 
     23 same a b = triage
     24   (triage true (ignored : false) (ignored ignored2 : false) b)
     25   (x : triage false (y : same x y) (ignored ignored2 : false) b)
     26   (x y : triage false (ignored : false) (u v : and? (same x u) (same y v)) b)
     27   a