authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2020-05-26 12:15:08-04:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2020-05-26 12:15:08-04:00
log62fefe864840e4d2c8bf4d6ad5509bcac141e7c3
tree6987bc1c7b9be6d30c8edf1b01aced6a86143968
parent5cdeac3b0eaf61bc07e45012d9c335a74f437276

std.fmt: non-exhaustive enums: avoid the loop when it's not necessary

1 files changed, 18 insertions(+), 32 deletions(-)

lib/std/fmt.zig+18-32
......@@ -359,38 +359,24 @@ pub fn formatType(
359359 },
360360 .Enum => |enumInfo| {
361361 try out_stream.writeAll(@typeName(T));
362
363 var has_name: bool = undefined;
364362 if (enumInfo.is_exhaustive) {
365 has_name = true;
366 } else {
367 has_name = false;
368 // Use @tagName only if value is one of known fields
369 inline for (enumInfo.fields) |enumField| {
370 if (@enumToInt(value) == enumField.value) {
371 has_name = true;
372 break;
373 }
374 }
363 try out_stream.writeAll(".");
364 try out_stream.writeAll(@tagName(value));
365 return;
375366 }
376367
377 var use_name = has_name;
378 if (comptime std.mem.eql(u8, fmt, "x") or
379 comptime std.mem.eql(u8, fmt, "X") or
380 comptime std.mem.eql(u8, fmt, "d") or
381 comptime std.mem.eql(u8, fmt, "b"))
382 {
383 use_name = false;
368 // Use @tagName only if value is one of known fields
369 inline for (enumInfo.fields) |enumField| {
370 if (@enumToInt(value) == enumField.value) {
371 try out_stream.writeAll(".");
372 try out_stream.writeAll(@tagName(value));
373 return;
374 }
384375 }
385376
386 if (use_name) {
387 try out_stream.writeAll(".");
388 try out_stream.writeAll(@tagName(value));
389 } else {
390 try out_stream.writeAll("(");
391 try formatType(@enumToInt(value), fmt, options, out_stream, max_depth);
392 try out_stream.writeAll(")");
393 }
377 try out_stream.writeAll("(");
378 try formatType(@enumToInt(value), fmt, options, out_stream, max_depth);
379 try out_stream.writeAll(")");
394380 },
395381 .Union => {
396382 try out_stream.writeAll(@typeName(T));
......@@ -1331,8 +1317,8 @@ test "enum" {
13311317 const value = Enum.Two;
13321318 try testFmt("enum: Enum.Two\n", "enum: {}\n", .{value});
13331319 try testFmt("enum: Enum.Two\n", "enum: {}\n", .{&value});
1334 try testFmt("enum: Enum(0)\n", "enum: {x}\n", .{Enum.One});
1335 try testFmt("enum: Enum(1)\n", "enum: {X}\n", .{Enum.Two});
1320 try testFmt("enum: Enum.One\n", "enum: {x}\n", .{Enum.One});
1321 try testFmt("enum: Enum.Two\n", "enum: {X}\n", .{Enum.Two});
13361322}
13371323
13381324test "non-exhaustive enum" {
......@@ -1344,9 +1330,9 @@ test "non-exhaustive enum" {
13441330 try testFmt("enum: Enum.One\n", "enum: {}\n", .{Enum.One});
13451331 try testFmt("enum: Enum.Two\n", "enum: {}\n", .{Enum.Two});
13461332 try testFmt("enum: Enum(4660)\n", "enum: {}\n", .{@intToEnum(Enum, 0x1234)});
1347 try testFmt("enum: Enum(f)\n", "enum: {x}\n", .{Enum.One});
1348 try testFmt("enum: Enum(beef)\n", "enum: {x}\n", .{Enum.Two});
1349 try testFmt("enum: Enum(BEEF)\n", "enum: {X}\n", .{Enum.Two});
1333 try testFmt("enum: Enum.One\n", "enum: {x}\n", .{Enum.One});
1334 try testFmt("enum: Enum.Two\n", "enum: {x}\n", .{Enum.Two});
1335 try testFmt("enum: Enum.Two\n", "enum: {X}\n", .{Enum.Two});
13501336 try testFmt("enum: Enum(1234)\n", "enum: {x}\n", .{@intToEnum(Enum, 0x1234)});
13511337}
13521338