core :: MapRead :: filter_keys
keys
that have a value.var map = new Map[String, String]
map["A"] = "a"
map["B"] = "b"
map["C"] = "c"
assert map.filter_keys(["B"]) == ["B"]
assert map.filter_keys(["A", "Z", "C"]) == ["A", "C"]
assert map.filter_keys(["X", "Y", "Z"]).is_empty
has_key
is used to filter.
# Return all elements of `keys` that have a value.
#
# ~~~
# var map = new Map[String, String]
# map["A"] = "a"
# map["B"] = "b"
# map["C"] = "c"
#
# assert map.filter_keys(["B"]) == ["B"]
# assert map.filter_keys(["A", "Z", "C"]) == ["A", "C"]
# assert map.filter_keys(["X", "Y", "Z"]).is_empty
# ~~~
#
# `has_key` is used to filter.
fun filter_keys(keys: Collection[nullable Object]): Array[K]
do
var res = new Array[K]
for e in keys do
if has_key(e) then res.add e
end
return res
end
lib/poset/poset.nit:734,2--755,4