bin_tree.txt

group :num 
  :int :float

type :bintree:leaf a
  @val a

type :bintree:branch a
  @left  :bintree a
  @right :bintree a

fun !map
arg f = :func a b
arg vec = :vec a
ret :vec b
  | len <- !len vec
  | ret <- !:vec len
  $ foreach idx elem vec
  | result <- !f elem
  | ret <- !set result idx vec
  $ repeat
  $ return ret

fun !sum
arg tree <- :bintree :num a
ret :num a
match tree
:bintree:leaf
  $ return leaf
:bintree:branch
  | left <- @left branch
  | right <- @right branch
  | lsum <- !sum left
  | rsum <- !sum right
  | sum <- !add lsum rsum
  $ return sum

# bintree constructor
fun !mytree
arg n <- :num
ret :bintree :num
  | l1 <- !:bintree:leaf n
  | inc <- !inc n
  | l2 <- !:bintree:leaf inc
  | root <- !:create_branch l1 l2
  # compiler returns pointer to `root` and keeps structs `root`, `l1`, and `l2` allocated
  $ return root

# creates a bintree, sums it
main
  | tree <- !mytree 10
  | sum <- !sum tree
  > print sum
# tree will be deallocated at the end of main, as well as its children (`l1`, `l2)