| author |  Andrew Kelley <andrew@ziglang.org> 2022-02-26 18:01:12-07:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2022-02-26 20:59:23-07:00 |
| log | 32e89a98d82c0f4505a3f3d4cd72e7db2eadfbb9 |
| tree | ad3f28c440c3ff6e1ad5cfd5bb05a867331e4b0e |
| parent | e999a925fade363886538722df7605b01da220d1 |
Sema: implement union value equality at comptime
Still TODO is extern unions.3 files changed, 27 insertions(+), 2 deletions(-)
src/type.zig+8
| ... | ... | @@ -2934,6 +2934,14 @@ pub const Type = extern union { |
| 2934 | 2934 | }; |
| 2935 | 2935 | } |
| 2936 | 2936 | |
| 2937 | /// Asserts the type is a union; returns the tag type, even if the tag will | |
| 2938 | /// not be stored at runtime. | |
| 2939 | pub fn unionTagTypeHypothetical(ty: Type) Type { | |
| 2940 | const union_obj = ty.cast(Payload.Union).?.data; | |
| 2941 | assert(union_obj.haveFieldTypes()); | |
| 2942 | return union_obj.tag_ty; | |
| 2943 | } | |
| 2944 | ||
| 2937 | 2945 | pub fn unionFields(ty: Type) Module.Union.Fields { |
| 2938 | 2946 | const union_obj = ty.cast(Payload.Union).?.data; |
| 2939 | 2947 | assert(union_obj.haveFieldTypes()); |
src/value.zig+19
| ... | ... | @@ -1902,6 +1902,25 @@ pub const Value = extern union { |
| 1902 | 1902 | } |
| 1903 | 1903 | return true; |
| 1904 | 1904 | }, |
| 1905 | .@"union" => { | |
| 1906 | const a_union = a.castTag(.@"union").?.data; | |
| 1907 | const b_union = b.castTag(.@"union").?.data; | |
| 1908 | switch (ty.containerLayout()) { | |
| 1909 | .Packed, .Extern => { | |
| 1910 | // In this case, we must disregard mismatching tags and compare | |
| 1911 | // based on the in-memory bytes of the payloads. | |
| 1912 | @panic("TODO implement comparison of extern union values"); | |
| 1913 | }, | |
| 1914 | .Auto => { | |
| 1915 | const tag_ty = ty.unionTagTypeHypothetical(); | |
| 1916 | if (!a_union.tag.eql(b_union.tag, tag_ty)) { | |
| 1917 | return false; | |
| 1918 | } | |
| 1919 | const active_field_ty = ty.unionFieldType(a_union.tag); | |
| 1920 | return a_union.val.eql(b_union.val, active_field_ty); | |
| 1921 | }, | |
| 1922 | } | |
| 1923 | }, | |
| 1905 | 1924 | else => {}, |
| 1906 | 1925 | } else if (a_tag == .null_value or b_tag == .null_value) { |
| 1907 | 1926 | return false; |
test/behavior/union.zig-2
| ... | ... | @@ -723,8 +723,6 @@ test "@enumToInt works on unions" { |
| 723 | 723 | } |
| 724 | 724 | |
| 725 | 725 | test "comptime union field value equality" { |
| 726 | if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO | |
| 727 | ||
| 728 | 726 | const a0 = Setter(Attribute{ .A = false }); |
| 729 | 727 | const a1 = Setter(Attribute{ .A = true }); |
| 730 | 728 | const a2 = Setter(Attribute{ .A = false }); |