Fuzion • Idioms • Idiom # 9: Create a Binary Tree data structure

Idiom # 9: Create a Binary Tree data structure

Code

# a Bin_Tree_Node is a value plus left and right sub-trees
#
Bin_Tree_Node(T type : has_total_order,
            val T,
            left, right bin_tree T) ref
is

# a bin_tree is either a Bin_Tree_Node or an empty tree represented by nil
#
bin_tree(T type : has_total_order) : choice<Bin_Tree_Node T, nil> is

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# a Bin_Tree_Node is a value plus left and right sub-trees
#
Bin_Tree_Node(T type : has_total_order,
            val T,
            left, right bin_tree T) ref
is
# a bin_tree is either a Bin_Tree_Node or an empty tree represented by nil
#
bin_tree(T type : has_total_order) : choice<Bin_Tree_Node T, nil> is
 
 
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What are effects?

Running Example

# a Bin_Tree_Node is a value plus left and right sub-trees
#
Bin_Tree_Node(T type : property.orderable,
            val T,
            left, right bin_tree T) ref
is

  # add element to this tree, return resulting tree
  #
  add (v T) bin_tree T =>
    l := if (v < val) (left .add v) else left
    r := if (v > val) (right.add v) else right
    Bin_Tree_Node val l r


  # print this tree
  #
  show =>
    left.show
    say val
    right.show


# a bin_tree is either a Bin_Tree_Node or an empty tree represented by nil
#
bin_tree(T type : property.orderable) : choice (Bin_Tree_Node T) nil is

  # add element to this tree, return resulting tree
  #
  add (v T) bin_tree T =>
    match bin_tree.this
      nil           => Bin_Tree_Node v nil nil
      n Bin_Tree_Node => n.add v

  # print this tree
  #
  show unit =>
    match bin_tree.this
      nil           =>
      n Bin_Tree_Node => n.show

for
  tree bin_tree String := nil, tree.add x
  x in ["dog", "elephant", "cat", "cat", "cat", "cat", "lion", "ant", "bee", "albatros", "hyena", "horse", "frog"]
else
  tree.show

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# a Bin_Tree_Node is a value plus left and right sub-trees
#
Bin_Tree_Node(T type : property.orderable,
            val T,
            left, right bin_tree T) ref
is
  # add element to this tree, return resulting tree
  #
  add (v T) bin_tree T =>
    l := if (v < val) (left .add v) else left
    r := if (v > val) (right.add v) else right
    Bin_Tree_Node val l r
  # print this tree
  #
  show =>
    left.show
    say val
    right.show
# a bin_tree is either a Bin_Tree_Node or an empty tree represented by nil
#
bin_tree(T type : property.orderable) : choice (Bin_Tree_Node T) nil is
  # add element to this tree, return resulting tree
  #
  add (v T) bin_tree T =>
    match bin_tree.this
      nil           => Bin_Tree_Node v nil nil
      n Bin_Tree_Node => n.add v
  # print this tree
  #
  show unit =>
    match bin_tree.this
      nil           =>
      n Bin_Tree_Node => n.show
for
  tree bin_tree String := nil, tree.add x
  x in ["dog", "elephant", "cat", "cat", "cat", "cat", "lion", "ant", "bee", "albatros", "hyena", "horse", "frog"]
else
  tree.show
 
 
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What are effects?

last changed: 2025-05-13

next: Idiom # 10: Shuffle a list