mirror-ghostty/src/datastruct/split_tree.zig

1130 lines
39 KiB
Zig

const std = @import("std");
const assert = std.debug.assert;
const build_config = @import("../build_config.zig");
const ArenaAllocator = std.heap.ArenaAllocator;
const Allocator = std.mem.Allocator;
/// SplitTree represents a tree of view types that can be divided.
///
/// Concretely for Ghostty, it represents a tree of terminal views. In
/// its basic state, there are no splits and it is a single full-sized
/// terminal. However, it can be split arbitrarily many times among two
/// axes (horizontal and vertical) to create a tree of terminal views.
///
/// This is an immutable tree structure, meaning all operations on it
/// will return a new tree with the operation applied. This allows us to
/// store versions of the tree in a history for easy undo/redo. To facilitate
/// this, the stored View type must implement reference counting; this is left
/// as an implementation detail of the View type.
///
/// The View type will be stored as a pointer within the tree and must
/// implement a number of functions to work properly:
///
/// - `fn ref(*View, Allocator) Allocator.Error!*View` - Increase a
/// reference count of the view. The Allocator will be the allocator provided
/// to the tree operation. This is allowed to copy the value if it wants to;
/// the returned value is expected to be a new reference (but that may
/// just be a copy).
///
/// - `fn unref(*View, Allocator) void` - Decrease the reference count of a
/// view. The Allocator will be the allocator provided to the tree
/// operation.
///
/// - `fn eql(*const View, *const View) bool` - Check if two views are equal.
///
/// Optionally the following functions can also be implemented:
///
/// - `fn splitTreeLabel(*const View) []const u8` - Return a label that is used
/// for the debug view. If this isn't specified then the node handle
/// will be used.
///
/// Note: for both the ref and unref functions, the allocator is optional.
/// If the functions take less arguments, then the allocator will not be
/// passed.
pub fn SplitTree(comptime V: type) type {
return struct {
const Self = @This();
/// The view that this tree contains.
pub const View = V;
/// The arena allocator used for all allocations in the tree.
/// Since the tree is an immutable structure, this lets us
/// cleanly free all memory when the tree is deinitialized.
arena: ArenaAllocator,
/// All the nodes in the tree. Node at index 0 is always the root.
nodes: []const Node,
/// An empty tree.
pub const empty: Self = .{
// Arena can be undefined because we have zero allocated nodes.
// If our nodes are empty our deinit function doesn't touch the
// arena.
.arena = undefined,
.nodes = &.{},
};
pub const Node = union(enum) {
leaf: *View,
split: Split,
/// A handle into the nodes array. This lets us keep track of
/// nodes with 16-bit handles rather than full pointer-width
/// values.
pub const Handle = u16;
};
pub const Split = struct {
layout: Layout,
ratio: f16,
left: Node.Handle,
right: Node.Handle,
pub const Layout = enum { horizontal, vertical };
pub const Direction = enum { left, right, down, up };
};
/// Initialize a new tree with a single view.
pub fn init(gpa: Allocator, view: *View) Allocator.Error!Self {
var arena = ArenaAllocator.init(gpa);
errdefer arena.deinit();
const alloc = arena.allocator();
const nodes = try alloc.alloc(Node, 1);
nodes[0] = .{ .leaf = try viewRef(view, gpa) };
errdefer viewUnref(view, gpa);
return .{
.arena = arena,
.nodes = nodes,
};
}
pub fn deinit(self: *Self) void {
// Important: only free memory if we have memory to free,
// because we use an undefined arena for empty trees.
if (self.nodes.len > 0) {
// Unref all our views
const gpa: Allocator = self.arena.child_allocator;
for (self.nodes) |node| switch (node) {
.leaf => |view| viewUnref(view, gpa),
.split => {},
};
self.arena.deinit();
}
self.* = undefined;
}
/// Clone this tree, returning a new tree with the same nodes.
pub fn clone(self: *const Self, gpa: Allocator) Allocator.Error!Self {
// Create a new arena allocator for the clone.
var arena = ArenaAllocator.init(gpa);
errdefer arena.deinit();
const alloc = arena.allocator();
// Allocate a new nodes array and copy the existing nodes into it.
const nodes = try alloc.dupe(Node, self.nodes);
// Increase the reference count of all the views in the nodes.
try refNodes(gpa, nodes);
return .{
.arena = arena,
.nodes = nodes,
};
}
/// Returns true if this is an empty tree.
pub fn isEmpty(self: *const Self) bool {
// An empty tree has no nodes.
return self.nodes.len == 0;
}
/// An iterator over all the views in the tree.
pub fn iterator(
self: *const Self,
) Iterator {
return .{ .nodes = self.nodes };
}
pub const Iterator = struct {
i: Node.Handle = 0,
nodes: []const Node,
pub const Entry = struct {
handle: Node.Handle,
view: *View,
};
pub fn next(self: *Iterator) ?Entry {
// If we have no nodes, return null.
if (self.i >= self.nodes.len) return null;
// Get the current node and increment the index.
const handle = self.i;
self.i += 1;
const node = self.nodes[handle];
return switch (node) {
.leaf => |v| .{ .handle = handle, .view = v },
.split => self.next(),
};
}
};
/// Insert another tree into this tree at the given node in the
/// specified direction. The other tree will be inserted in the
/// new direction. For example, if the direction is "right" then
/// `insert` is inserted right of the existing node.
///
/// The allocator will be used for the newly created tree.
/// The previous trees will not be freed, but reference counts
/// for the views will be increased accordingly for the new tree.
pub fn split(
self: *const Self,
gpa: Allocator,
at: Node.Handle,
direction: Split.Direction,
insert: *const Self,
) Allocator.Error!Self {
// The new arena for our new tree.
var arena = ArenaAllocator.init(gpa);
errdefer arena.deinit();
const alloc = arena.allocator();
// We know we're going to need the sum total of the nodes
// between the two trees plus one for the new split node.
const nodes = try alloc.alloc(Node, self.nodes.len + insert.nodes.len + 1);
if (nodes.len > std.math.maxInt(Node.Handle)) return error.OutOfMemory;
// We can copy our nodes exactly as they are, since they're
// mostly not changing (only `at` is changing).
@memcpy(nodes[0..self.nodes.len], self.nodes);
// We can copy the destination nodes as well directly next to
// the source nodes. We just have to go through and offset
// all the handles in the destination tree to account for
// the shift.
const nodes_inserted = nodes[self.nodes.len..][0..insert.nodes.len];
@memcpy(nodes_inserted, insert.nodes);
for (nodes_inserted) |*node| switch (node.*) {
.leaf => {},
.split => |*s| {
// We need to offset the handles in the split
s.left += @intCast(self.nodes.len);
s.right += @intCast(self.nodes.len);
},
};
// Determine our split layout and if we're on the left
const layout: Split.Layout, const left: bool = switch (direction) {
.left => .{ .horizontal, true },
.right => .{ .horizontal, false },
.up => .{ .vertical, true },
.down => .{ .vertical, false },
};
// Copy our previous value to the end of the nodes list and
// create our new split node.
nodes[nodes.len - 1] = nodes[at];
nodes[at] = .{ .split = .{
.layout = layout,
.ratio = 0.5,
.left = @intCast(if (left) self.nodes.len else nodes.len - 1),
.right = @intCast(if (left) nodes.len - 1 else self.nodes.len),
} };
// We need to increase the reference count of all the nodes.
try refNodes(gpa, nodes);
return .{ .arena = arena, .nodes = nodes };
}
/// Remove a node from the tree.
pub fn remove(
self: *Self,
gpa: Allocator,
at: Node.Handle,
) Allocator.Error!Self {
assert(at < self.nodes.len);
// If we're removing node zero then we're clearing the tree.
if (at == 0) return .empty;
// The new arena for our new tree.
var arena = ArenaAllocator.init(gpa);
errdefer arena.deinit();
const alloc = arena.allocator();
// Allocate our new nodes list with the number of nodes we'll
// need after the removal.
const nodes = try alloc.alloc(Node, self.countAfterRemoval(
0,
at,
0,
));
// Traverse the tree and copy all our nodes into place.
assert(self.removeNode(
nodes,
0,
0,
at,
) > 0);
// Increase the reference count of all the nodes.
try refNodes(gpa, nodes);
return .{
.arena = arena,
.nodes = nodes,
};
}
fn removeNode(
self: *Self,
nodes: []Node,
new_offset: Node.Handle,
current: Node.Handle,
target: Node.Handle,
) Node.Handle {
assert(current != target);
switch (self.nodes[current]) {
// Leaf is simple, just copy it over. We don't ref anything
// yet because it'd make undo (errdefer) harder. We do that
// all at once later.
.leaf => |view| {
nodes[new_offset] = .{ .leaf = view };
return 1;
},
.split => |s| {
// If we're removing one of the split node sides then
// we remove the split node itself as well and only add
// the other (non-removed) side.
if (s.left == target) return self.removeNode(
nodes,
new_offset,
s.right,
target,
);
if (s.right == target) return self.removeNode(
nodes,
new_offset,
s.left,
target,
);
// Neither side is being directly removed, so we traverse.
const left = self.removeNode(
nodes,
new_offset + 1,
s.left,
target,
);
assert(left > 0);
const right = self.removeNode(
nodes,
new_offset + 1 + left,
s.right,
target,
);
assert(right > 0);
nodes[new_offset] = .{ .split = .{
.layout = s.layout,
.ratio = s.ratio,
.left = new_offset + 1,
.right = new_offset + 1 + left,
} };
return left + right + 1;
},
}
}
/// Returns the number of nodes that would be needed to store
/// the tree if the target node is removed.
fn countAfterRemoval(
self: *Self,
current: Node.Handle,
target: Node.Handle,
acc: usize,
) usize {
assert(current != target);
return switch (self.nodes[current]) {
// Leaf is simple, always takes one node.
.leaf => acc + 1,
// Split is slightly more complicated. If either side is the
// target to remove, then we remove the split node as well
// so our count is just the count of the other side.
//
// If neither side is the target, then we count both sides
// and add one to account for the split node itself.
.split => |s| if (s.left == target) self.countAfterRemoval(
s.right,
target,
acc,
) else if (s.right == target) self.countAfterRemoval(
s.left,
target,
acc,
) else self.countAfterRemoval(
s.left,
target,
acc,
) + self.countAfterRemoval(
s.right,
target,
acc,
) + 1,
};
}
/// Reference all the nodes in the given slice, handling unref if
/// any fail. This should be called LAST so you don't have to undo
/// the refs at any further point after this.
fn refNodes(gpa: Allocator, nodes: []Node) Allocator.Error!void {
// We need to increase the reference count of all the nodes.
// Careful accounting here so that we properly unref on error
// only the nodes we referenced.
var reffed: usize = 0;
errdefer for (0..reffed) |i| {
switch (nodes[i]) {
.split => {},
.leaf => |view| viewUnref(view, gpa),
}
};
for (0..nodes.len) |i| {
switch (nodes[i]) {
.split => {},
.leaf => |view| nodes[i] = .{ .leaf = try viewRef(view, gpa) },
}
reffed = i;
}
assert(reffed == nodes.len - 1);
}
/// Spatial representation of the split tree. See spatial.
pub const Spatial = struct {
/// The slots of the spatial representation in the same order
/// as the tree it was created from.
slots: []const Slot,
pub const empty: Spatial = .{ .slots = &.{} };
const Slot = struct {
x: f16,
y: f16,
width: f16,
height: f16,
};
pub fn deinit(self: *const Spatial, alloc: Allocator) void {
alloc.free(self.slots);
self.* = undefined;
}
};
/// Spatial representation of the split tree. This can be used to
/// better understand the layout of the tree in a 2D space.
///
/// The bounds of the representation are always based on each split
/// being exactly 1 unit wide and high. The x and y coordinates
/// are offsets into that space. This means that the spatial
/// representation is a normalized representation of the actual
/// space.
///
/// The top-left corner of the tree is always (0, 0).
///
/// We use a normalized form because we can calculate it without
/// accessing to the actual rendered view sizes. These actual sizes
/// may not be available at various times because GUI toolkits often
/// only make them available once they're part of a widget tree and
/// a SplitTree can represent views that aren't currently visible.
pub fn spatial(
self: *const Self,
alloc: Allocator,
) Allocator.Error!Spatial {
// No nodes, empty spatial representation.
if (self.nodes.len == 0) return .empty;
// Get our total dimensions.
const dim = self.dimensions(0);
// Create our slots which will match our nodes exactly.
const slots = try alloc.alloc(Spatial.Slot, self.nodes.len);
errdefer alloc.free(slots);
slots[0] = .{
.x = 0,
.y = 0,
.width = @floatFromInt(dim.width),
.height = @floatFromInt(dim.height),
};
self.fillSpatialSlots(slots, 0);
return .{ .slots = slots };
}
fn fillSpatialSlots(
self: *const Self,
slots: []Spatial.Slot,
current: Node.Handle,
) void {
assert(slots[current].width > 0 and slots[current].height > 0);
switch (self.nodes[current]) {
// Leaf node, current slot is already filled by caller.
.leaf => {},
.split => |s| {
switch (s.layout) {
.horizontal => {
slots[s.left] = .{
.x = slots[current].x,
.y = slots[current].y,
.width = slots[current].width * s.ratio,
.height = slots[current].height,
};
slots[s.right] = .{
.x = slots[current].x + slots[current].width * s.ratio,
.y = slots[current].y,
.width = slots[current].width * (1 - s.ratio),
.height = slots[current].height,
};
},
.vertical => {
slots[s.left] = .{
.x = slots[current].x,
.y = slots[current].y,
.width = slots[current].width,
.height = slots[current].height * s.ratio,
};
slots[s.right] = .{
.x = slots[current].x,
.y = slots[current].y + slots[current].height * s.ratio,
.width = slots[current].width,
.height = slots[current].height * (1 - s.ratio),
};
},
}
self.fillSpatialSlots(slots, s.left);
self.fillSpatialSlots(slots, s.right);
},
}
}
/// Get the dimensions of the tree starting from the given node.
///
/// This creates relative dimensions (see Spatial) by assuming each
/// leaf is exactly 1x1 unit in size.
fn dimensions(self: *const Self, current: Node.Handle) struct {
width: u16,
height: u16,
} {
return switch (self.nodes[current]) {
.leaf => .{ .width = 1, .height = 1 },
.split => |s| split: {
const left = self.dimensions(s.left);
const right = self.dimensions(s.right);
break :split switch (s.layout) {
.horizontal => .{
.width = left.width + right.width,
.height = @max(left.height, right.height),
},
.vertical => .{
.width = @max(left.width, right.width),
.height = left.height + right.height,
},
};
},
};
}
/// Format the tree in a human-readable format. By default this will
/// output a diagram followed by a textual representation. This can
/// be controlled via the formatting string:
///
/// - `diagram` - Output a diagram of the split tree only.
/// - `text` - Output a textual representation of the split tree only.
/// - Empty - Output both a diagram and a textual representation.
///
pub fn format(
self: *const Self,
comptime fmt: []const u8,
options: std.fmt.FormatOptions,
writer: anytype,
) !void {
_ = options;
if (self.nodes.len == 0) {
try writer.writeAll("empty");
return;
}
if (std.mem.eql(u8, fmt, "diagram")) {
self.formatDiagram(writer) catch
try writer.writeAll("failed to draw split tree diagram");
} else if (std.mem.eql(u8, fmt, "text")) {
try self.formatText(writer, 0, 0);
} else if (fmt.len == 0) {
self.formatDiagram(writer) catch {};
try self.formatText(writer, 0, 0);
} else {
return error.InvalidFormat;
}
}
fn formatText(
self: *const Self,
writer: anytype,
current: Node.Handle,
depth: usize,
) !void {
for (0..depth) |_| try writer.writeAll(" ");
switch (self.nodes[current]) {
.leaf => |v| if (@hasDecl(View, "splitTreeLabel"))
try writer.print("leaf: {s}\n", .{v.splitTreeLabel()})
else
try writer.print("leaf: {d}\n", .{current}),
.split => |s| {
try writer.print("split (layout: {s}, ratio: {d:.2})\n", .{
@tagName(s.layout),
s.ratio,
});
try self.formatText(writer, s.left, depth + 1);
try self.formatText(writer, s.right, depth + 1);
},
}
}
fn formatDiagram(
self: *const Self,
writer: anytype,
) !void {
// Use our arena's GPA to allocate some intermediate memory.
// Requiring allocation for formatting is nasty but this is really
// only used for debugging and testing and shouldn't hit OOM
// scenarios.
var arena: ArenaAllocator = .init(self.arena.child_allocator);
defer arena.deinit();
const alloc = arena.allocator();
// Get our spatial representation.
const sp = spatial: {
const sp = try self.spatial(alloc);
// Scale our spatial representation to have minimum width/height 1.
var min_w: f16 = 1;
var min_h: f16 = 1;
for (sp.slots) |slot| {
min_w = @min(min_w, slot.width);
min_h = @min(min_h, slot.height);
}
const ratio_w: f16 = 1 / min_w;
const ratio_h: f16 = 1 / min_h;
const slots = try alloc.dupe(Spatial.Slot, sp.slots);
for (slots) |*slot| {
slot.x *= ratio_w;
slot.y *= ratio_h;
slot.width *= ratio_w;
slot.height *= ratio_h;
}
break :spatial .{ .slots = slots };
};
// The width we need for the largest label.
const max_label_width: usize = max_label_width: {
if (!@hasDecl(View, "splitTreeLabel")) {
break :max_label_width std.math.log10(sp.slots.len) + 1;
}
var max: usize = 0;
for (self.nodes) |node| switch (node) {
.split => {},
.leaf => |view| {
const label = view.splitTreeLabel();
max = @max(max, label.len);
},
};
break :max_label_width max;
};
// We need space for whitespace and ASCII art so add that.
// We need to accommodate the leaf handle, whitespace, and
// then the border.
const cell_width = cell_width: {
// Border + whitespace + label + whitespace + border.
break :cell_width 2 + max_label_width + 2;
};
const cell_height = cell_height: {
// Border + label + border. No whitespace needed on the
// vertical axis.
break :cell_height 1 + 1 + 1;
};
// Make a grid that can fit our entire ASCII diagram. We know
// the width/height based on node 0.
const grid = grid: {
// Get our initial width/height. Each leaf is 1x1 in this.
// We round up for this because partial widths/heights should
// take up an extra cell.
var width: usize = @intFromFloat(@ceil(sp.slots[0].width));
var height: usize = @intFromFloat(@ceil(sp.slots[0].height));
// We need space for whitespace and ASCII art so add that.
// We need to accommodate the leaf handle, whitespace, and
// then the border.
width *= cell_width;
height *= cell_height;
const rows = try alloc.alloc([]u8, height);
for (0..rows.len) |y| {
rows[y] = try alloc.alloc(u8, width + 1);
@memset(rows[y], ' ');
rows[y][width] = '\n';
}
break :grid rows;
};
// Draw each node
for (sp.slots, 0..) |slot, handle| {
// We only draw leaf nodes. Splits are only used for layout.
const node = self.nodes[handle];
switch (node) {
.leaf => {},
.split => continue,
}
var x: usize = @intFromFloat(@floor(slot.x));
var y: usize = @intFromFloat(@floor(slot.y));
var width: usize = @intFromFloat(@max(@floor(slot.width), 1));
var height: usize = @intFromFloat(@max(@floor(slot.height), 1));
x *= cell_width;
y *= cell_height;
width *= cell_width;
height *= cell_height;
// Top border
{
const top = grid[y][x..][0..width];
top[0] = '+';
for (1..width - 1) |i| top[i] = '-';
top[width - 1] = '+';
}
// Bottom border
{
const bottom = grid[y + height - 1][x..][0..width];
bottom[0] = '+';
for (1..width - 1) |i| bottom[i] = '-';
bottom[width - 1] = '+';
}
// Left border
for (y + 1..y + height - 1) |y_cur| grid[y_cur][x] = '|';
for (y + 1..y + height - 1) |y_cur| grid[y_cur][x + width - 1] = '|';
// Get our label text
var buf: [10]u8 = undefined;
const label: []const u8 = if (@hasDecl(View, "splitTreeLabel"))
node.leaf.splitTreeLabel()
else
try std.fmt.bufPrint(&buf, "{d}", .{handle});
// Draw the handle in the center
const x_mid = width / 2 + x;
const y_mid = height / 2 + y;
const label_width = label.len;
const label_start = x_mid - label_width / 2;
const row = grid[y_mid][label_start..];
_ = try std.fmt.bufPrint(row, "{s}", .{label});
}
// Output every row
for (grid) |row| {
try writer.writeAll(row);
}
}
fn viewRef(view: *View, gpa: Allocator) Allocator.Error!*View {
const func = @typeInfo(@TypeOf(View.ref)).@"fn";
return switch (func.params.len) {
1 => view.ref(),
2 => try view.ref(gpa),
else => @compileError("invalid view ref function"),
};
}
fn viewUnref(view: *View, gpa: Allocator) void {
const func = @typeInfo(@TypeOf(View.unref)).@"fn";
switch (func.params.len) {
1 => view.unref(),
2 => view.unref(gpa),
else => @compileError("invalid view unref function"),
}
}
/// Make this a valid gobject if we're in a GTK environment.
pub const getGObjectType = switch (build_config.app_runtime) {
.gtk, .@"gtk-ng" => @import("gobject").ext.defineBoxed(
Self,
.{
// To get the type name we get the non-qualified type name
// of the view and append that to `GhosttySplitTree`.
.name = name: {
const type_name = @typeName(View);
const last = if (std.mem.lastIndexOfScalar(
u8,
type_name,
'.',
)) |idx|
type_name[idx + 1 ..]
else
type_name;
assert(last.len > 0);
break :name "GhosttySplitTree" ++ last;
},
.funcs = .{
.copy = &struct {
fn copy(self: *Self) callconv(.c) *Self {
const ptr = @import("glib").ext.create(Self);
const alloc = self.arena.child_allocator;
ptr.* = self.clone(alloc) catch @panic("oom");
return ptr;
}
}.copy,
.free = &struct {
fn free(self: *Self) callconv(.c) void {
self.deinit();
@import("glib").ext.destroy(self);
}
}.free,
},
},
),
.none => void,
};
};
}
const TestTree = SplitTree(TestView);
const TestView = struct {
const Self = @This();
label: []const u8,
pub fn ref(self: *Self, alloc: Allocator) Allocator.Error!*Self {
const ptr = try alloc.create(Self);
ptr.* = self.*;
return ptr;
}
pub fn unref(self: *Self, alloc: Allocator) void {
alloc.destroy(self);
}
pub fn splitTreeLabel(self: *const Self) []const u8 {
return self.label;
}
};
test "SplitTree: empty tree" {
const testing = std.testing;
const alloc = testing.allocator;
var t: TestTree = .empty;
defer t.deinit();
const str = try std.fmt.allocPrint(alloc, "{}", .{t});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\empty
);
}
test "SplitTree: single node" {
const testing = std.testing;
const alloc = testing.allocator;
var v: TestTree.View = .{ .label = "A" };
var t: TestTree = try .init(alloc, &v);
defer t.deinit();
const str = try std.fmt.allocPrint(alloc, "{diagram}", .{t});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---+
\\| A |
\\+---+
\\
);
}
test "SplitTree: split horizontal" {
const testing = std.testing;
const alloc = testing.allocator;
var v1: TestTree.View = .{ .label = "A" };
var t1: TestTree = try .init(alloc, &v1);
defer t1.deinit();
var v2: TestTree.View = .{ .label = "B" };
var t2: TestTree = try .init(alloc, &v2);
defer t2.deinit();
var t3 = try t1.split(
alloc,
0, // at root
.right, // split right
&t2, // insert t2
);
defer t3.deinit();
{
const str = try std.fmt.allocPrint(alloc, "{}", .{t3});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---++---+
\\| A || B |
\\+---++---+
\\split (layout: horizontal, ratio: 0.50)
\\ leaf: A
\\ leaf: B
\\
);
}
// Split right at B
var vC: TestTree.View = .{ .label = "C" };
var tC: TestTree = try .init(alloc, &vC);
defer tC.deinit();
var it = t3.iterator();
var t4 = try t3.split(
alloc,
while (it.next()) |entry| {
if (std.mem.eql(u8, entry.view.label, "B")) {
break entry.handle;
}
} else return error.NotFound,
.right,
&tC,
);
defer t4.deinit();
{
const str = try std.fmt.allocPrint(alloc, "{}", .{t4});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+--------++---++---+
\\| A || B || C |
\\+--------++---++---+
\\split (layout: horizontal, ratio: 0.50)
\\ leaf: A
\\ split (layout: horizontal, ratio: 0.50)
\\ leaf: B
\\ leaf: C
\\
);
}
// Split right at C
var vD: TestTree.View = .{ .label = "D" };
var tD: TestTree = try .init(alloc, &vD);
defer tD.deinit();
it = t4.iterator();
var t5 = try t4.split(
alloc,
while (it.next()) |entry| {
if (std.mem.eql(u8, entry.view.label, "C")) {
break entry.handle;
}
} else return error.NotFound,
.right,
&tD,
);
defer t5.deinit();
{
const str = try std.fmt.allocPrint(alloc, "{}", .{t5});
defer alloc.free(str);
try testing.expectEqualStrings(
\\+------------------++--------++---++---+
\\| A || B || C || D |
\\+------------------++--------++---++---+
\\split (layout: horizontal, ratio: 0.50)
\\ leaf: A
\\ split (layout: horizontal, ratio: 0.50)
\\ leaf: B
\\ split (layout: horizontal, ratio: 0.50)
\\ leaf: C
\\ leaf: D
\\
, str);
}
}
test "SplitTree: split vertical" {
const testing = std.testing;
const alloc = testing.allocator;
var v1: TestTree.View = .{ .label = "A" };
var t1: TestTree = try .init(alloc, &v1);
defer t1.deinit();
var v2: TestTree.View = .{ .label = "B" };
var t2: TestTree = try .init(alloc, &v2);
defer t2.deinit();
var t3 = try t1.split(
alloc,
0, // at root
.down, // split down
&t2, // insert t2
);
defer t3.deinit();
const str = try std.fmt.allocPrint(alloc, "{diagram}", .{t3});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---+
\\| A |
\\+---+
\\+---+
\\| B |
\\+---+
\\
);
}
test "SplitTree: remove leaf" {
const testing = std.testing;
const alloc = testing.allocator;
var v1: TestTree.View = .{ .label = "A" };
var t1: TestTree = try .init(alloc, &v1);
defer t1.deinit();
var v2: TestTree.View = .{ .label = "B" };
var t2: TestTree = try .init(alloc, &v2);
defer t2.deinit();
var t3 = try t1.split(
alloc,
0, // at root
.right, // split right
&t2, // insert t2
);
defer t3.deinit();
// Remove "A"
var it = t3.iterator();
var t4 = try t3.remove(
alloc,
while (it.next()) |entry| {
if (std.mem.eql(u8, entry.view.label, "A")) {
break entry.handle;
}
} else return error.NotFound,
);
defer t4.deinit();
const str = try std.fmt.allocPrint(alloc, "{diagram}", .{t4});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---+
\\| B |
\\+---+
\\
);
}
test "SplitTree: split twice, remove intermediary" {
const testing = std.testing;
const alloc = testing.allocator;
var v1: TestTree.View = .{ .label = "A" };
var t1: TestTree = try .init(alloc, &v1);
defer t1.deinit();
var v2: TestTree.View = .{ .label = "B" };
var t2: TestTree = try .init(alloc, &v2);
defer t2.deinit();
var v3: TestTree.View = .{ .label = "C" };
var t3: TestTree = try .init(alloc, &v3);
defer t3.deinit();
// A | B horizontal.
var split1 = try t1.split(
alloc,
0, // at root
.right, // split right
&t2, // insert t2
);
defer split1.deinit();
// Insert C below that.
var split2 = try split1.split(
alloc,
0, // at root
.down, // split down
&t3, // insert t3
);
defer split2.deinit();
{
const str = try std.fmt.allocPrint(alloc, "{diagram}", .{split2});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---++---+
\\| A || B |
\\+---++---+
\\+--------+
\\| C |
\\+--------+
\\
);
}
// Remove "B"
var it = split2.iterator();
var split3 = try split2.remove(
alloc,
while (it.next()) |entry| {
if (std.mem.eql(u8, entry.view.label, "B")) {
break entry.handle;
}
} else return error.NotFound,
);
defer split3.deinit();
{
const str = try std.fmt.allocPrint(alloc, "{diagram}", .{split3});
defer alloc.free(str);
try testing.expectEqualStrings(str,
\\+---+
\\| A |
\\+---+
\\+---+
\\| C |
\\+---+
\\
);
}
// Remove every node from split2 (our most complex one), which should
// never crash. We don't test the result is correct, this just verifies
// we don't hit any assertion failures.
for (0..split2.nodes.len) |i| {
var t = try split2.remove(alloc, @intCast(i));
t.deinit();
}
}