authorgravatar for quae@daurnimator.comdaurnimator <quae@daurnimator.com> 2019-04-12 12:23:44+02:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2019-05-03 01:54:49-04:00
logfca3e3a73f157d93ae3d57f90c13512acfbe9aa4
tree7cdd658422f60221443bfee6d0de18b0e0d18080
parent3552180143a86432bfec3e71ba2fdd7aaebb0549

std: add std.ArrayList.orderedRemove

1 files changed, 38 insertions(+), 0 deletions(-)

std/array_list.zig+38
......@@ -111,6 +111,17 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) type {
111111 new_item_ptr.* = item;
112112 }
113113
114 pub fn orderedRemove(self: *Self, i: usize) T {
115 const newlen = self.len - 1;
116 if (newlen == i) return self.pop();
117
118 const old_item = self.at(i);
119 for (self.items[i..newlen]) |*b, j| b.* = self.items[i + 1 + j];
120 self.items[newlen] = undefined;
121 self.len = newlen;
122 return old_item;
123 }
124
114125 /// Removes the element at the specified index and returns it.
115126 /// The empty slot is filled from the end of the list.
116127 pub fn swapRemove(self: *Self, i: usize) T {
......@@ -279,6 +290,33 @@ test "std.ArrayList.basic" {
279290 testing.expect(list.pop() == 33);
280291}
281292
293test "std.ArrayList.orderedRemove" {
294 var list = ArrayList(i32).init(debug.global_allocator);
295 defer list.deinit();
296
297 try list.append(1);
298 try list.append(2);
299 try list.append(3);
300 try list.append(4);
301 try list.append(5);
302 try list.append(6);
303 try list.append(7);
304
305 //remove from middle
306 testing.expectEqual(i32(4), list.orderedRemove(3));
307 testing.expectEqual(i32(5), list.at(3));
308 testing.expectEqual(usize(6), list.len);
309
310 //remove from end
311 testing.expectEqual(i32(7), list.orderedRemove(5));
312 testing.expectEqual(usize(5), list.len);
313
314 //remove from front
315 testing.expectEqual(i32(1), list.orderedRemove(0));
316 testing.expectEqual(i32(2), list.at(0));
317 testing.expectEqual(usize(4), list.len);
318}
319
282320test "std.ArrayList.swapRemove" {
283321 var list = ArrayList(i32).init(debug.global_allocator);
284322 defer list.deinit();