plum

import std/Str

import std/Bool

import std/Number

fun loopSum(limit: Int) -> Int =

  total := 0

  for i := range limit

    if i == 3

      continue

    if i == 8

      break

    total = total + i

  return total

fun classify(n: Int) -> Str =

  if n < 0

    return "negative"

  else if n == 0

    return "zero"

  else

    return "positive"

fun countdown(start: Int) -> Int =

  i := start

  while i > 0

    i = i - 1

  return i

fun placeholder() =

  todo

fun checkPositive(n: Int) =

  assert n > 0

# ---- tail-expression and assert regression tests ----

fun bindExample(n: Int) -> Int =

  match n

    x => x

fun abs(n: Int) -> Int =

  if n < 0

    -n

  else

    n

fun classifySign(n: Int) -> Int =

  match n

    0 => 1

    x =>

      if x < 0

        -1

      else

        2

fun describeMagnitude(n: Int) -> Int =

  match n

    0 =>

      return 100

    x => x * 2

enum TailOption =

  | TailSome(Int)

  | TailNone

fun unwrapTailOr(o: TailOption, default: Int) -> Int =

  match o

    TailSome(v) => v

    TailNone => default

fun checkPositiveAndReturn(n: Int) -> Int =

  assert n > 0

  n

test "tail match without return runs correctly"

  assert bindExample(5) == 5

test "tail if without return runs correctly"

  assert abs(-7) == 7

test "tail if nested inside match arm without return runs correctly"

  assert classifySign(-5) == -1

test "tail match mixing return and bare expr arms runs correctly"

  assert describeMagnitude(21) == 42

test "tail enum match without return runs correctly"

  assert unwrapTailOr(TailSome(9), 0) == 9

test "assert passes through on true"

  assert checkPositiveAndReturn(5) == 5