factotum/nice-data
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

value: simplify list conversion code

Browse Source 
There was really no reason to use ArrayLists here when the list length
is known ahead of time. This slightly shortens the code and should be
slightly more memory/stack efficient.
This commit is contained in:
torque
2023-11-23 17:54:14 -08:00
parent 39619e7d6b
commit 98eac68929
1 changed files with 18 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
src/parser/value.zig
View File

@@ -131,15 +131,18 @@ pub const Value = union(enum) {
} }
}, },
.list, .inline_list => |lst| { .list, .inline_list => |lst| {
var result = try std.ArrayList(ptr.child).initCapacity(allocator, lst.items.len); const result = try allocator.alloc(ptr.child, lst.items.len + @intFromBool(ptr.sentinel != null));
errdefer result.deinit();
for (lst.items) |item| { for (result[0..lst.items.len], lst.items) |*res, item| {
result.appendAssumeCapacity(try item.convertTo(ptr.child, allocator, options)); res.* = try item.convertTo(ptr.child, allocator, options);
} }
if (ptr.sentinel) |sent| {
return try result.toOwnedSliceSentinel(@as(*align(1) const ptr.child, @ptrCast(sent)).*); if (comptime ptr.sentinel) |sentinel| {
const sval = @as(*align(1) const ptr.child, @ptrCast(sentinel)).*;
result[lst.items.len] = sval;
return result[0..lst.items.len :sval];
} else { } else {
return try result.toOwnedSlice(); return result;
} }
}, },
else => return error.BadValue, else => return error.BadValue,
@@ -151,7 +154,7 @@ pub const Value = union(enum) {
result.* = try self.convertTo(ptr.child, allocator, options); result.* = try self.convertTo(ptr.child, allocator, options);
return result; return result;
}, },
else => @compileError("Cannot deserialize into many-pointer or c-pointer " ++ @typeName(T)), // do not support many or C item pointers. else => @compileError("Cannot deserialize into many-pointer or c-pointer " ++ @typeName(T)),
}, },
.Array => |arr| { .Array => |arr| {
// TODO: There is ambiguity here because a document expecting a list // TODO: There is ambiguity here because a document expecting a list
@@ -168,14 +171,12 @@ pub const Value = union(enum) {
} else return error.BadValue; } else return error.BadValue;
}, },
.list, .inline_list => |lst| { .list, .inline_list => |lst| {
var storage = try std.ArrayList(arr.child).initCapacity(allocator, arr.len); if (lst.items.len != arr.len) return error.BadValue;
defer storage.deinit();
for (lst.items) |item| {
storage.appendAssumeCapacity(try item.convertTo(arr.child, allocator, options));
}
// this may result in a big stack allocation, which is not ideal
var result: T = undefined; var result: T = undefined;
@memcpy(&result, storage.items); for (&result, lst.items) |*res, item| {
res.* = try item.convertTo(arr.child, allocator, options);
}
return result; return result;
}, },
else => return error.BadValue, else => return error.BadValue,
@@ -190,8 +191,8 @@ pub const Value = union(enum) {
.list, .inline_list => |list| { .list, .inline_list => |list| {
if (list.items.len != stt.fields.len) return error.BadValue; if (list.items.len != stt.fields.len) return error.BadValue;
var result: T = undefined; var result: T = undefined;
inline for (stt.fields, 0..) |field, idx| { inline for (stt.fields, &result, list.items) |field, *res, item| {
result[idx] = try list.items[idx].convertTo(field.type, allocator, options); res.* = try item.convertTo(field.type, allocator, options);
} }
return result; return result;
}, },