def __call__(self, expr: E.Apply, env: E.Env) -> V.Base:
assert len(expr.arguments) == 2
lhs = expr.arguments[0]
rhs = expr.arguments[1]
if isinstance(lhs.type, T.Array):
arr = lhs.eval(env)
assert isinstance(arr, V.Array)
assert isinstance(arr.type, T.Array)
assert isinstance(arr.value, list)
idx = rhs.eval(env).expect(T.Int()).value
if idx < 0 or idx >= len(arr.value):
raise Error.OutOfBounds(rhs)
return arr.value[idx] # pyre-fixme
if isinstance(lhs.type, T.Map):
mp = lhs.eval(env)
assert isinstance(mp, V.Map)
assert isinstance(mp.type, T.Map)
assert mp.type.item_type is not None
assert isinstance(mp.value, list)
ans = None
key = rhs.eval(env).expect(mp.type.item_type[0])
for k, v in mp.value:
if key == k:
ans = v.expect(mp.type.item_type[1])
if ans is None:
raise Error.OutOfBounds(rhs) # TODO: KeyNotFound
return ans # pyre-fixme
assert False # pyre-fixme
def _call_eager(self, expr: E.Apply, arguments: List[V.Base]) -> V.Base:
assert len(expr.arguments) == 2 and len(arguments) == 2
lhs = arguments[0]
rhs = arguments[1]
if isinstance(lhs, V.Array):
assert isinstance(rhs, V.Int)
if rhs.value < 0 or rhs.value >= len(lhs.value):
raise Error.OutOfBounds(expr.arguments[1])
return lhs.value[rhs.value]
if isinstance(lhs, V.Map):
mty = expr.arguments[0].type
assert isinstance(mty, T.Map)
key = rhs.coerce(mty.item_type[0])
ans = None
for k, v in lhs.value:
if rhs == k:
ans = v
if ans is None:
raise Error.OutOfBounds(expr.arguments[1]) # TODO: KeyNotFound
return ans
assert False
def infer_type(self, expr: E.Apply) -> T.Base:
assert len(expr.arguments) == 2
lhs = expr.arguments[0]
rhs = expr.arguments[1]
if isinstance(lhs.type, T.Array):
if isinstance(lhs, E.Array) and not lhs.items:
# the user wrote: [][idx]
raise Error.OutOfBounds(expr)
try:
rhs.typecheck(T.Int())
except Error.StaticTypeMismatch:
raise Error.StaticTypeMismatch(rhs, T.Int(), rhs.type, "Array index") from None
return lhs.type.item_type
if isinstance(lhs.type, T.Map):
if lhs.type.item_type is None:
raise Error.OutOfBounds(expr)
try:
rhs.typecheck(lhs.type.item_type[0])
except Error.StaticTypeMismatch:
raise Error.StaticTypeMismatch(
rhs, lhs.type.item_type[0], rhs.type, "Map key"
) from None
return lhs.type.item_type[1]
raise Error.NotAnArray(lhs)
