add new command impl, Sequence

src/hncore/command/Interface.zig

@@ -34,6 +34,12 @@ pub const Mock = struct {
     target   : ?*i32  = null,
     destroyed: ?*bool = null,
 
+    pub fn init(alloc: std.mem.Allocator, target: ?*i32, destroyed: ?*bool) !Self {
+        return make(alloc, Mock {
+            .target    = target,
+            .destroyed = destroyed,
+        });
+    }
     pub fn deinit(self: *@This(), _: anytype) void {
         if (self.destroyed) |ptr| {
             ptr.* = true;
@@ -117,10 +123,7 @@ test {
     var value: i32 = 0;
     var destroyed = false;
     {
-        const cmd = try Self.make(std.testing.allocator, Mock {
+        const cmd = try Mock.init(std.testing.allocator, &value, &destroyed);
-            .target    = &value,
-            .destroyed = &destroyed,
-        });
         defer cmd.deinit();
 
         try cmd.apply();

src/hncore/command/generic.zig

@@ -0,0 +1,88 @@
+const std = @import("std");
+
+const Interface = @import("./Interface.zig");
+
+///
+const Sequence = struct {
+    ///
+    const Self = @This();
+
+    ///
+    commands: []Interface,
+
+    ///
+    pub fn init(alloc: std.mem.Allocator, commands: []const Interface) !Interface {
+        const list = try alloc.dupe(Interface, commands);
+        errdefer alloc.free(list);
+        return try Interface.make(alloc, Self {
+            .commands = list,
+        });
+    }
+
+    ///
+    pub fn deinit(self: *Self, alloc: std.mem.Allocator) void {
+        for (self.commands) |command| {
+            command.deinit();
+        }
+        alloc.free(self.commands);
+    }
+
+    ///
+    pub fn apply(self: *Self, _: std.mem.Allocator) Interface.Error!void {
+        for (self.commands) |command| {
+            try command.apply();
+        }
+    }
+
+    ///
+    pub fn revert(self: *Self, _: std.mem.Allocator) Interface.Error!void {
+        var i = self.commands.len;
+        while (i > 0) {
+            i -= 1;
+            try self.commands[i].revert();
+        }
+    }
+};
+
+test {
+    var value1: i32 = 0;
+    var value2: i32 = 0;
+    var value3: i32 = 0;
+
+    var finished1 = false;
+    var finished2 = false;
+    var finished3 = false;
+
+    {
+        var seq = blk: {
+            const alloc = std.testing.allocator;
+
+            var cmd1 = try Interface.Mock.init(alloc, &value1, &finished1);
+            errdefer cmd1.deinit();
+
+            var cmd2 = try Interface.Mock.init(alloc, &value2, &finished2);
+            errdefer cmd2.deinit();
+
+            var cmd3 = try Interface.Mock.init(alloc, &value3, &finished3);
+            errdefer cmd3.deinit();
+
+            break :blk try Sequence.init(std.testing.allocator, &[_]Interface {
+                cmd1, cmd2, cmd3,
+            });
+        };
+        defer seq.deinit();
+
+        try seq.apply();
+        try std.testing.expectEqual(1, value1);
+        try std.testing.expectEqual(1, value2);
+        try std.testing.expectEqual(1, value3);
+
+        try seq.revert();
+        try std.testing.expectEqual(0, value1);
+        try std.testing.expectEqual(0, value2);
+        try std.testing.expectEqual(0, value3);
+    }
+    try std.testing.expect(finished1);
+    try std.testing.expect(finished2);
+    try std.testing.expect(finished3);
+}

src/hncore/command/root.zig

@@ -1,6 +1,7 @@
 pub const Interface = @import("./Interface.zig");
 
-pub const task = @import("./task.zig");
+pub const generic = @import("./generic.zig");
+pub const task    = @import("./task.zig");
 
 test {
     @import("std").testing.refAllDecls(@This());