const std = @import("index.zig"); const debug = std.debug; const assert = debug.assert; const assertError = debug.assertError; const mem = std.mem; const Allocator = mem.Allocator; pub fn ArrayList(comptime T: type) type { return AlignedArrayList(T, @alignOf(T)); } pub fn AlignedArrayList(comptime T: type, comptime A: u29) type { return struct { const Self = this; /// Use toSlice instead of slicing this directly, because if you don't /// specify the end position of the slice, this will potentially give /// you uninitialized memory. items: []align(A) T, len: usize, allocator: *Allocator, /// Deinitialize with `deinit` or use `toOwnedSlice`. pub fn init(allocator: *Allocator) Self { return Self{ .items = []align(A) T{}, .len = 0, .allocator = allocator, }; } pub fn deinit(self: Self) void { self.allocator.free(self.items); } pub fn toSlice(self: Self) []align(A) T { return self.items[0..self.len]; } pub fn toSliceConst(self: Self) []align(A) const T { return self.items[0..self.len]; } pub fn at(self: Self, i: usize) T { return self.toSliceConst()[i]; } /// Sets the value at index `i`, or returns `error.OutOfBounds` if /// the index is not in range. pub fn setOrError(self: Self, i: usize, item: T) !void { if (i >= self.len) return error.OutOfBounds; self.items[i] = item; } /// Sets the value at index `i`, asserting that the value is in range. pub fn set(self: *Self, i: usize, item: T) void { assert(i < self.len); self.items[i] = item; } pub fn count(self: Self) usize { return self.len; } /// ArrayList takes ownership of the passed in slice. The slice must have been /// allocated with `allocator`. /// Deinitialize with `deinit` or use `toOwnedSlice`. pub fn fromOwnedSlice(allocator: *Allocator, slice: []align(A) T) Self { return Self{ .items = slice, .len = slice.len, .allocator = allocator, }; } /// The caller owns the returned memory. ArrayList becomes empty. pub fn toOwnedSlice(self: *Self) []align(A) T { const allocator = self.allocator; const result = allocator.alignedShrink(T, A, self.items, self.len); self.* = init(allocator); return result; } pub fn insert(self: *Self, n: usize, item: T) !void { try self.ensureCapacity(self.len + 1); self.len += 1; mem.copyBackwards(T, self.items[n + 1 .. self.len], self.items[n .. self.len - 1]); self.items[n] = item; } pub fn insertSlice(self: *Self, n: usize, items: []align(A) const T) !void { try self.ensureCapacity(self.len + items.len); self.len += items.len; mem.copyBackwards(T, self.items[n + items.len .. self.len], self.items[n .. self.len - items.len]); mem.copy(T, self.items[n .. n + items.len], items); } pub fn append(self: *Self, item: T) !void { const new_item_ptr = try self.addOne(); new_item_ptr.* = item; } /// Removes the element at the specified index and returns it. /// The empty slot is filled from the end of the list. pub fn swapRemove(self: *Self, i: usize) T { if (self.len - 1 == i) return self.pop(); const slice = self.toSlice(); const old_item = slice[i]; slice[i] = self.pop(); return old_item; } /// Removes the element at the specified index and returns it /// or an error.OutOfBounds is returned. If no error then /// the empty slot is filled from the end of the list. pub fn swapRemoveOrError(self: *Self, i: usize) !T { if (i >= self.len) return error.OutOfBounds; return self.swapRemove(i); } pub fn appendSlice(self: *Self, items: []align(A) const T) !void { try self.ensureCapacity(self.len + items.len); mem.copy(T, self.items[self.len..], items); self.len += items.len; } pub fn resize(self: *Self, new_len: usize) !void { try self.ensureCapacity(new_len); self.len = new_len; } pub fn shrink(self: *Self, new_len: usize) void { assert(new_len <= self.len); self.len = new_len; } pub fn ensureCapacity(self: *Self, new_capacity: usize) !void { var better_capacity = self.items.len; if (better_capacity >= new_capacity) return; while (true) { better_capacity += better_capacity / 2 + 8; if (better_capacity >= new_capacity) break; } self.items = try self.allocator.alignedRealloc(T, A, self.items, better_capacity); } pub fn addOne(self: *Self) !*T { const new_length = self.len + 1; try self.ensureCapacity(new_length); const result = &self.items[self.len]; self.len = new_length; return result; } pub fn pop(self: *Self) T { self.len -= 1; return self.items[self.len]; } pub fn popOrNull(self: *Self) ?T { if (self.len == 0) return null; return self.pop(); } pub const Iterator = struct { list: *const Self, // how many items have we returned count: usize, pub fn next(it: *Iterator) ?T { if (it.count >= it.list.len) return null; const val = it.list.at(it.count); it.count += 1; return val; } pub fn reset(it: *Iterator) void { it.count = 0; } }; pub fn iterator(self: *const Self) Iterator { return Iterator{ .list = self, .count = 0, }; } }; } test "std.ArrayList.basic" { var bytes: [1024]u8 = undefined; const allocator = &std.heap.FixedBufferAllocator.init(bytes[0..]).allocator; var list = ArrayList(i32).init(allocator); defer list.deinit(); // setting on empty list is out of bounds assertError(list.setOrError(0, 1), error.OutOfBounds); { var i: usize = 0; while (i < 10) : (i += 1) { list.append(@intCast(i32, i + 1)) catch unreachable; } } { var i: usize = 0; while (i < 10) : (i += 1) { assert(list.items[i] == @intCast(i32, i + 1)); } } for (list.toSlice()) |v, i| { assert(v == @intCast(i32, i + 1)); } for (list.toSliceConst()) |v, i| { assert(v == @intCast(i32, i + 1)); } assert(list.pop() == 10); assert(list.len == 9); list.appendSlice([]const i32{ 1, 2, 3, }) catch unreachable; assert(list.len == 12); assert(list.pop() == 3); assert(list.pop() == 2); assert(list.pop() == 1); assert(list.len == 9); list.appendSlice([]const i32{}) catch unreachable; assert(list.len == 9); // can only set on indices < self.len list.set(7, 33); list.set(8, 42); assertError(list.setOrError(9, 99), error.OutOfBounds); assertError(list.setOrError(10, 123), error.OutOfBounds); assert(list.pop() == 42); assert(list.pop() == 33); } test "std.ArrayList.swapRemove" { var list = ArrayList(i32).init(debug.global_allocator); defer list.deinit(); try list.append(1); try list.append(2); try list.append(3); try list.append(4); try list.append(5); try list.append(6); try list.append(7); //remove from middle assert(list.swapRemove(3) == 4); assert(list.at(3) == 7); assert(list.len == 6); //remove from end assert(list.swapRemove(5) == 6); assert(list.len == 5); //remove from front assert(list.swapRemove(0) == 1); assert(list.at(0) == 5); assert(list.len == 4); } test "std.ArrayList.swapRemoveOrError" { var list = ArrayList(i32).init(debug.global_allocator); defer list.deinit(); // Test just after initialization assertError(list.swapRemoveOrError(0), error.OutOfBounds); // Test after adding one item and remote it try list.append(1); assert((try list.swapRemoveOrError(0)) == 1); assertError(list.swapRemoveOrError(0), error.OutOfBounds); // Test after adding two items and remote both try list.append(1); try list.append(2); assert((try list.swapRemoveOrError(1)) == 2); assert((try list.swapRemoveOrError(0)) == 1); assertError(list.swapRemoveOrError(0), error.OutOfBounds); // Test out of bounds with one item try list.append(1); assertError(list.swapRemoveOrError(1), error.OutOfBounds); // Test out of bounds with two items try list.append(2); assertError(list.swapRemoveOrError(2), error.OutOfBounds); } test "std.ArrayList.iterator" { var list = ArrayList(i32).init(debug.global_allocator); defer list.deinit(); try list.append(1); try list.append(2); try list.append(3); var count: i32 = 0; var it = list.iterator(); while (it.next()) |next| { assert(next == count + 1); count += 1; } assert(count == 3); assert(it.next() == null); it.reset(); count = 0; while (it.next()) |next| { assert(next == count + 1); count += 1; if (count == 2) break; } it.reset(); assert(it.next().? == 1); } test "std.ArrayList.insert" { var list = ArrayList(i32).init(debug.global_allocator); defer list.deinit(); try list.append(1); try list.append(2); try list.append(3); try list.insert(0, 5); assert(list.items[0] == 5); assert(list.items[1] == 1); assert(list.items[2] == 2); assert(list.items[3] == 3); } test "std.ArrayList.insertSlice" { var list = ArrayList(i32).init(debug.global_allocator); defer list.deinit(); try list.append(1); try list.append(2); try list.append(3); try list.append(4); try list.insertSlice(1, []const i32{ 9, 8, }); assert(list.items[0] == 1); assert(list.items[1] == 9); assert(list.items[2] == 8); assert(list.items[3] == 2); assert(list.items[4] == 3); assert(list.items[5] == 4); const items = []const i32{1}; try list.insertSlice(0, items[0..0]); assert(list.len == 6); assert(list.items[0] == 1); }