erg/tests/should_err/subtyping.er
2024-04-28 18:53:30 +09:00

50 lines
1.1 KiB
Python

f(x: Nat): Int = x
y: Ratio = f 1
# Erg's type checking does not necessarily enlarge the type. So this is OK.
z: Int = y
# But this is invalid.
invalid: 10..<20 = z #ERR
for! [(1, 2)], ((i, j),) =>
k = i + 1 # OK
print! k
for! [(1, 2)], ((i, j),) =>
k = i + "a" # ERR
print! k
for! zip([1], ["a"]), ((i: Int, s: Str),) =>
k = i + 1
l = s + "b"
print! k, l
# ERR: i should be Int
for! zip([1], ["a"]), ((i: Str, s: Str),) => # ERR
k = i + "a"
print! k
for! zip([1], ["a"]), ((i, s),) =>
k = i + "a" # ERR
print! k
for! zip([1+1], ["a"+"b"]), ((i, s),) => # i: Nat, s: Str
print! i + 1
print! s + "b"
print! s + 1 # ERR
print! i + "a" # ERR
for! "aaa", a =>
print! a # OK
for! "aaa", a =>
print! a + 1 # ERR
inty|T :> Nat, T <: Int|(x: T) = x + x
inty 0 # OK
inty 1.1 # ERR
_: List!({"a", "b"}, 2) = !["a", "b"] # OK
_: List!({"a", "b", "c"}, 2) = !["a", "b"] # OK
_: List!({"a", "c"}, 2) = !["a", "b"] # ERR
_: List!({"a"}, 2) = !["a", "b"] # ERR
ii _: Iterable(Iterable(Str)) = None
ii [1] # ERR
ii [[1]] # ERR
ii [["a"]]
ii ["aaa"] # Str <: Iterable Str