File: switch.ls

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node-livescript 1.6.1%2Bdfsg-1
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switch 10
case 5 then ok 0
case 'a'
  true
  false
  ok 0
case 10 then ok 1

  #! Mid-switch comment with whitespace

    #! and multi line
case 11 then ok 0
default ok 0


func = (num) ->
  switch num
  case 2, 4, 6
    Boolean true
  case [1, 3, 5]
    Boolean false
  default
eq func(2), true
eq func(6), true
eq func(3), false
eq func(8), void


# One-liner
eq void, switch case 1 then break
eq 1   , switch case 0 then break default 1
eq 2   , switch case 1 then (while 0 then continue); 2
eq 3   , do -> switch 0 case 1 then -> 2 default 3
eq 4   , if 1 then switch 2 case 3 then default 4


compileThrows 'inconvertible statement' 3 '''
  for ever
    !switch
      continue
'''


ok switch \words
  case (<[ nonbare words ]>) then false
  case  <[    bare words ]>
    switch Function::toString
    case ok<[valueOf toString]> then true
, '`case` expands bare arrays'


# Sans-topic
eq ok, switch
case null                    then 0
case !1                      then 1
case '' not of {''}          then 2
case [] not instanceof Array then 3
case true is false           then 4
case 'x' < 'y' > 'z'         then 5
case 'a' in  <[ b c ]>       then 6
case 'd' in (<[ e f ]>)      then 7
default ok


eq '''
var that;
switch (false) {
case !1:
  return;
case !2:
  throw me;
case !3:
  break;
case !4:
  // fallthrough
case !(that = 5):
  that;
  break;
case !(6 || 7 || 8):
  break;
case !void 8:
  break;
default:
  9;
}
''', LiveScript.compile '''
switch
case 1 then return
case 2 then throw me
case 3 then break
case 4 then fallthrough
case 5 then that
case 6 [7 8] then
case[] then
default 9
''', {+bare,-header}


# `that`
eq 1, switch 1 case 1 then that

while 1
  eq 3, switch 3 case 3 then that
  break

switch case [0, 2, 4,] then eq 2, that

# `that` with default - #508
switch 10 | _ => that

# Sans-condition
switch
  ok 1 'caseless switch is allowed'
  break if true
  ok 0 'for early breaking'

# case |
switch
| false then ok 0 | false then ok 0
| false
  ok 0
| true
  ok 1
| true  then ok 0

# then =>
switch
| false => ok 0
| false =>
  ok 0
| true  => ok 1
| true  => ok 0

# otherwise, _
eq otherwise?, false

switch
| false     => ok 0
| otherwise => ok 1

switch 2 + 3
case 6 then ok 0
case _ then ok 1

switch
| false => ok 0
| _     => ok 1

switch 2 + 3
case 6 then ok 0
case otherwise then ok 1

# implicit switches
boom1 = ->
  case false => 1
  case otherwise => 2

  3

eq 3 boom1!

do ->
  | false => ok 0
  | true => ok 1

do ~>
  | false => ok 0
  | true => ok 1

boom2 = ->
  | false => 1
  | otherwise => 2

  3

eq 3 boom2!

# when
switch
when false then ok 0
when true  then ok 1

# else
switch
| false => ok 0
else ok 1

#### match
x = 2
match x
| (== 3) => ok 0
| (== 2) => ok 1
| _      => ok 0

match ++x
| (== 4)          => ok 0
| (== 3) or (==8) => ok 1
| _               => ok 0

false-func = -> false
true-func  = -> true

# no subject
match
| false-func => ok 0
| true-func  => ok 1
| otherwise  => ok 0

# multiple topics
even = --> it % 2 == 0
odd = (not) . even
x = 1
y = 2
match x, y
| odd,  odd  => ok 0
| even, even => ok 0
| odd,  even => ok 1
| otherwise  => ok 0

# literals
x = 5
y = \moo
z = true
match x, y, z
| 5, \moo, false => ok 0
| 4, \moo, true  => ok 0
| 5, \moo, true  => ok 1
| otherwise      => ok 0

x = [1 2 3]
y = 'haha'
z = {+foo, moo: 2, g: {hi: \?}}
match x
| [2 4 6]   => ok 0
| [1 2 3 4] => ok 0
| [1 2 _]   => ok 1
| otherwise => ok 0

match z
| {-foo, goo: 23, g: {hi: \?}} => ok 0
| {+foo, moo: 2,  g: _}        => ok 1
| otherwise                    => ok 0

match x, y, z
| [1 2 3], /^ha/g, {foo: true, moo: 2, g: {hi: \!}} => ok 0
| [1 2 3], /^ha/g, {foo: true, moo: 2, g: {hi: \?}} => ok 1
| otherwise                                         => ok 0

match 2
| even and 2 => ok 1
| otherwise  => ok 0

match 3, \haha
| _, 'muhaha' => ok 0
| even, _     => ok 0
| _, 'haha'   => ok 1
| _           => ok 0

take = (n, [x, ...xs]:list) ->
  match n, list
  | (<= 0), _  => []
  | _     , [] => []
  | otherwise  => [x] ++ take n - 1, xs

eq '1,2,3' "#{ take 3, [1 to 10] }"

x = -2
match x
| -2 => ok 1
| _  => ok 0

match 1, 3, 3
| 1, 1, 2 or 3 => ok 0
| 1, 2 or 3, 3 => ok 1
| _            => ok 0


# [LiveScript#1025](https://github.com/gkz/LiveScript/issues/1025)
# Expressions starting from `_` were treated as placeholders in `match` cases
_ = -> -> false
_.isString = -> typeof it == \string
match 1
| _.isString   => ok 0
| (_.isString) => ok 0
| _!           => ok 0
match \foo
| _.isString   => ok 1

# other examples of Chains with tails
match \foo
| 'barbaz'~starts-with => ok 0
| 'foobar'~starts-with => ok 1
| otherwise            => ok 0

# [LiveScript#926](https://github.com/gkz/LiveScript/issues/926)
# `match` wasn't binding `this` correctly in expression position
o =
  bar: 42
  run: ->
    foo:
      match @bar
      | (== 42) => true

ok o.run!foo

# [gkz/LiveScript#931](https://github.com/gkz/LiveScript/issues/931)
# Let's not produce unreachable `break` statements
test-cases =
  '''
    foo = switch bar
    | \\a =>
      if baz then 1 else 2
    | \\b => 3
  '''
  '''
    foo = switch bar
    | \\a =>
      switch baz
      | \\1 => 1
      | otherwise => 2
    | \\b => 3
  '''
  '''
    switch foo
    | \\a =>
      if bar
        return 1
      else throw new Error
    | \\b => baz!
  '''

for test-cases
  compiled = LiveScript.compile .., {+bare,-header}
  eq -1 compiled.index-of(\break), "no break in:\n#compiled"