# If `sub` is a safe subtype of `sup` then return `sub`.
# If `sub` is an unsafe subtype (ie an implicit cast is required), then return `sup`.
#
- # The point of the return type is to determinate the usable type on an expression:
+ # The point of the return type is to determinate the usable type on an expression when `autocast` is true:
# If the suptype is safe, then the return type is the one on the expression typed by `sub`.
# Is the subtype is unsafe, then the return type is the one of an implicit cast on `sup`.
- fun check_subtype(node: ANode, sub, sup: MType): nullable MType
+ fun check_subtype(node: ANode, sub, sup: MType, autocast: Bool): nullable MType
do
if self.is_subtype(sub, sup) then return sub
- if self.is_subtype(sub, self.anchor_to(sup)) then
+ if autocast and self.is_subtype(sub, self.anchor_to(sup)) then
# FIXME workaround to the current unsafe typing policy. To remove once fixed virtual types exists.
#node.debug("Unsafe typing: expected {sup}, got {sub}")
return sup
if sup == null then return null # Forward error
- var res = check_subtype(nexpr, sub, sup)
+ var res = check_subtype(nexpr, sub, sup, true)
if res != sub then
nexpr.implicit_cast_to = res
end
var value_type = v.visit_expr_subtype(self.n_value, msignature.mparameters.first.mtype)
if value_type == null then return null # Skip error
- v.check_subtype(self, rettype, writetype)
+ v.check_subtype(self, rettype, writetype, false)
return rettype
end
end
end
set_comprehension(e)
if mtype != null then
- if v.check_subtype(e, t, mtype) == null then return # Skip error
+ if v.check_subtype(e, t, mtype, false) == null then return # Forward error
if t == mtype then useless = true
else
mtypes.add(t)