Skip to content

Fix map union optimization for open maps #15322

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
josevalim merged 1 commit into from
Apr 29, 2026
Merged

Fix map union optimization for open maps #15322

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions lib/elixir/lib/module/types/descr.ex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3000,8 +3000,12 @@ defmodule Module.Types.Descr do
end
end

defp map_union_strategy([], [], _tag1, _tag2, status) do
status
defp map_union_strategy([], [], tag1, tag2, status) do
case status do
:left_subtype_of_right when tag1 == :open and tag2 == :closed -> :none
:right_subtype_of_left when tag1 == :closed and tag2 == :open -> :none
_ -> status
end
end

defp map_union_strategy(l1, l2, tag1, tag2, status) do
Expand Down
8 changes: 8 additions & 0 deletions lib/elixir/test/elixir/module/types/descr_test.exs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -115,6 +115,14 @@ defmodule Module.Types.DescrTest do
a_integer_open = open_map(a: integer())
assert equal?(union(closed_map(a: integer()), a_integer_open), a_integer_open)

closed = closed_map(a: integer(), b: atom())
open = open_map(a: integer(), b: boolean())

assert subtype?(closed, union(closed, open))
assert subtype?(open, union(closed, open))
assert subtype?(closed, union(open, closed))
assert subtype?(open, union(open, closed))

# Domain key types
atom_to_atom = open_map([{domain_key(:atom), atom()}])
atom_to_integer = open_map([{domain_key(:atom), integer()}])
Expand Down
Loading