implement Command interface

src/hncore/Command.zig

@@ -1,51 +0,0 @@
-//!
-
-const std = @import("std");
-
-///
-pub const Self  = @This();
-
-///
-pub const Error = error {
-    ///
-    AllocationFailure,
-
-    ///
-    InvalidState,
-
-    ///
-    Unknown,
-};
-
-///
-pub const VTable = struct {
-    ///
-    deinit: *const fn(ctx: *anyopaque) void,
-
-    ///
-    apply: *const fn(ctx: *anyopaque) Error!void,
-
-    ///
-    revert: *const fn(ctx: *anyopaque) Error!void,
-};
-
-///
-ctx: *anyopaque,
-
-///
-vtable: *const VTable,
-
-///
-pub fn deinit(self: Self) void {
-    self.vtable.deinit(self.ctx);
-}
-
-///
-pub fn apply(self: Self) !void {
-    return self.vtable.apply(self.ctx);
-}
-
-///
-pub fn revert(self: Self) !void {
-    return self.vtable.revert(self.ctx);
-}

src/hncore/CommandHistory.zig

@@ -1,12 +1,12 @@
 const std = @import("std");
 
-const Command = @import("./Command.zig");
+const CommandIF = @import("./command/root.zig").Interface;
 
 ///
 const Self = @This();
 
 ///
-const CommandList = std.ArrayList(Command);
+const CommandList = std.ArrayList(CommandIF);
 
 ///
 commands: CommandList,
@@ -31,7 +31,7 @@ pub fn deinit(self: *Self) void {
 }
 
 ///
-pub fn exec(self: *Self, command: Command) !void {
+pub fn exec(self: *Self, command: CommandIF) !void {
     if (self.head >= self.commands.items.len) {
         try self.commands.append(command);
     } else {
@@ -74,25 +74,8 @@ pub fn isRedoAvailable(self: *const Self) bool {
 }
 
 test {
-    const Mock = struct {
+    var value1: i32 = 0;
-        const vt = Command.VTable {
+    var value2: i32 = 0;
-            .deinit = deinit_,
-            .apply  = apply_,
-            .revert = revert_,
-        };
-        count: i32 = 0,
-        fn deinit_(_: *anyopaque) void { }
-        fn apply_(ctx: *anyopaque) Command.Error!void {
-            var self: *@This() = @ptrCast(@alignCast(ctx));
-            self.count += 1;
-        }
-        fn revert_(ctx: *anyopaque) Command.Error!void {
-            var self: *@This() = @ptrCast(@alignCast(ctx));
-            self.count -= 1;
-        }
-    };
-    var mock1 = Mock {};
-    var mock2 = Mock {};
 
     var history = init(std.testing.allocator);
     defer history.deinit();
@@ -102,48 +85,50 @@ test {
     try std.testing.expectError(error.NoCommand, history.undo());
     try std.testing.expectError(error.NoCommand, history.redo());
 
-    try history.exec(Command { .ctx = &mock1, .vtable = &Mock.vt, });
+    try history.exec(
+        try CommandIF.make(std.testing.allocator, CommandIF.Mock { .target = &value1, }));
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), false);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
 
     try history.undo();
     try std.testing.expectEqual(history.isUndoAvailable(), false);
     try std.testing.expectEqual(history.isRedoAvailable(), true);
-    try std.testing.expectEqual(mock1.count, 0);
+    try std.testing.expectEqual(value1, 0);
 
     try history.redo();
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), false);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
 
-    try history.exec(Command { .ctx = &mock2, .vtable = &Mock.vt, });
+    try history.exec(
+        try CommandIF.make(std.testing.allocator, CommandIF.Mock { .target = &value2, }));
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), false);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
-    try std.testing.expectEqual(mock2.count, 1);
+    try std.testing.expectEqual(value2, 1);
 
     try history.undo();
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), true);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
-    try std.testing.expectEqual(mock2.count, 0);
+    try std.testing.expectEqual(value2, 0);
 
     try history.redo();
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), false);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
-    try std.testing.expectEqual(mock2.count, 1);
+    try std.testing.expectEqual(value2, 1);
 
     try history.undo();
     try std.testing.expectEqual(history.isUndoAvailable(), true);
     try std.testing.expectEqual(history.isRedoAvailable(), true);
-    try std.testing.expectEqual(mock1.count, 1);
+    try std.testing.expectEqual(value1, 1);
-    try std.testing.expectEqual(mock2.count, 0);
+    try std.testing.expectEqual(value2, 0);
 
     try history.undo();
     try std.testing.expectEqual(history.isUndoAvailable(), false);
     try std.testing.expectEqual(history.isRedoAvailable(), true);
-    try std.testing.expectEqual(mock1.count, 0);
+    try std.testing.expectEqual(value1, 0);
-    try std.testing.expectEqual(mock2.count, 0);
+    try std.testing.expectEqual(value2, 0);
 }

src/hncore/Task.zig

@@ -38,16 +38,14 @@ pub fn deinit(self: *Self) void {
 }
 
 ///
-pub fn setSummary(self: *Self, v: []const u8) ![:0]const u8 {
+pub fn setSummary(self: *Self, v: []const u8) !void {
     self.alloc.free(self.summary);
     self.summary = try self.alloc.dupeZ(u8, v);
-    return self.summary;
 }
 ///
-pub fn setDetails(self: *Self, v: []const u8) ![:0]const u8 {
+pub fn setDetails(self: *Self, v: []const u8) !void {
     self.alloc.free(self.details);
     self.details = try self.alloc.dupeZ(u8, v);
-    return self.details;
 }
 
 test {
@@ -57,15 +55,15 @@ test {
     try std.testing.expectEqualStrings("", task.summary);
     try std.testing.expectEqualStrings("", task.details);
 
-    _ = try task.setSummary("helloworld");
+    try task.setSummary("helloworld");
     try std.testing.expectEqualStrings("helloworld", task.summary);
     try std.testing.expectEqualStrings("", task.details);
 
-    _ = try task.setDetails("good afternoon");
+    try task.setDetails("good afternoon");
     try std.testing.expectEqualStrings("helloworld", task.summary);
     try std.testing.expectEqualStrings("good afternoon", task.details);
 
-    _ = try task.setSummary("goodbye");
+    try task.setSummary("goodbye");
     try std.testing.expectEqualStrings("goodbye", task.summary);
     try std.testing.expectEqualStrings("good afternoon", task.details);
 }

src/hncore/command/Interface.zig

@@ -0,0 +1,134 @@
+//!
+
+const std = @import("std");
+
+///
+pub const Self  = @This();
+
+///
+pub const Error = error {
+    ///
+    OutOfMemory,
+
+    ///
+    InvalidState,
+
+    ///
+    Unknown,
+};
+
+///
+pub const VTable = struct {
+    ///
+    deinit: *const fn(ctx: *anyopaque) void,
+
+    ///
+    apply: *const fn(ctx: *anyopaque) Error!void,
+
+    ///
+    revert: *const fn(ctx: *anyopaque) Error!void,
+};
+
+///
+pub const Mock = struct {
+    target   : ?*i32  = null,
+    destroyed: ?*bool = null,
+
+    pub fn deinit(self: *@This(), _: anytype) void {
+        if (self.destroyed) |ptr| {
+            ptr.* = true;
+        }
+    }
+    pub fn apply(self: *@This(), _: anytype) !void {
+        if (self.target) |ptr| {
+            ptr.* += 1;
+        }
+    }
+    pub fn revert(self: *@This(), _: anytype) !void {
+        if (self.target) |ptr| {
+            ptr.* -= 1;
+        }
+    }
+};
+
+///
+ctx: *anyopaque,
+
+///
+vtable: *const VTable,
+
+///
+pub fn deinit(self: Self) void {
+    self.vtable.deinit(self.ctx);
+}
+
+///
+pub fn apply(self: Self) !void {
+    return self.vtable.apply(self.ctx);
+}
+
+///
+pub fn revert(self: Self) !void {
+    return self.vtable.revert(self.ctx);
+}
+
+///
+pub fn make(alloc: std.mem.Allocator, ctx: anytype) !Self {
+    const Target = @TypeOf(ctx);
+    const Wrapper = struct {
+        const vtable = VTable {
+            .deinit = @This().del,
+            .apply  = @This().apply,
+            .revert = @This().revert,
+        };
+
+        alloc: std.mem.Allocator,
+        ctx  : Target,
+
+        fn new(alloc2: std.mem.Allocator, ctx2: Target) !*@This() {
+            const self = try alloc2.create(@This());
+            self.* = .{
+                .alloc = alloc2,
+                .ctx   = ctx2,
+            };
+            return self;
+        }
+        fn del(selfp: *anyopaque) void {
+            const self: *@This() = @ptrCast(@alignCast(selfp));
+            self.ctx.deinit(self.alloc);
+            self.alloc.destroy(self);
+        }
+        fn apply(selfp: *anyopaque) Error!void {
+            const self: *@This() = @ptrCast(@alignCast(selfp));
+            return self.ctx.apply(self.alloc);
+        }
+        fn revert(selfp: *anyopaque) Error!void {
+            const self: *@This() = @ptrCast(@alignCast(selfp));
+            return self.ctx.revert(self.alloc);
+        }
+    };
+    return Self {
+        .ctx    = try Wrapper.new(alloc, ctx),
+        .vtable = &Wrapper.vtable,
+    };
+}
+
+test {
+    var value: i32 = 0;
+    var destroyed = false;
+    {
+        const cmd = try Self.make(std.testing.allocator, Mock {
+            .target    = &value,
+            .destroyed = &destroyed,
+        });
+        defer cmd.deinit();
+
+        try cmd.apply();
+        try std.testing.expectEqual(value, 1);
+
+        try cmd.revert();
+        try std.testing.expectEqual(value, 0);
+    }
+
+    try std.testing.expect(destroyed);
+}

src/hncore/command/root.zig

@@ -0,0 +1,7 @@
+pub const Interface = @import("./Interface.zig");
+
+pub const task = @import("./task.zig");
+
+test {
+    @import("std").testing.refAllDecls(@This());
+}

src/hncore/command/task.zig

@@ -0,0 +1,67 @@
+const std = @import("std");
+
+const Interface = @import("./Interface.zig");
+
+const Task = @import("../Task.zig");
+
+///
+const SetSummary = struct {
+    ///
+    const Self = @This();
+
+    ///
+    target: *Task,
+
+    ///
+    summary: [:0]const u8,
+
+    ///
+    pub fn init(alloc: std.mem.Allocator, task: *Task, summary: []const u8) !Interface {
+        const summaryDup = try alloc.dupeZ(u8, summary);
+        errdefer alloc.free(summaryDup);
+        return try Interface.make(alloc, Self {
+            .target  = task,
+            .summary = summaryDup,
+        });
+    }
+
+    ///
+    pub fn deinit(self: *Self, alloc: std.mem.Allocator) void {
+        alloc.free(self.summary);
+    }
+
+    ///
+    pub fn apply(self: *Self, alloc: std.mem.Allocator) Interface.Error!void {
+        const old = try alloc.dupeZ(u8, self.target.summary);
+        errdefer alloc.free(old);
+
+        try self.target.setSummary(self.summary);
+        alloc.free(self.summary);
+
+        self.summary = old;
+    }
+
+    ///
+    pub fn revert(self: *Self, alloc: std.mem.Allocator) Interface.Error!void {
+        return self.apply(alloc);
+    }
+};
+
+test {
+    const TaskStore = @import("../TaskStore.zig");
+
+    var tasks = TaskStore.init(std.testing.allocator);
+    defer tasks.deinit();
+
+    var task = try tasks.add();
+    try task.setSummary("helloworld");
+
+    var sut = try SetSummary.init(std.testing.allocator, task, "goodbye");
+    defer sut.deinit();
+
+    try sut.apply();
+    try std.testing.expectEqualStrings("goodbye", task.summary);
+
+    try sut.revert();
+    try std.testing.expectEqualStrings("helloworld", task.summary);
+}

src/hncore/root.zig

@@ -1,4 +1,5 @@
-pub const Command        = @import("./Command.zig");
+pub const command = @import("./command/root.zig");
+
 pub const CommandHistory = @import("./CommandHistory.zig");
 pub const Task           = @import("./Task.zig");
 pub const TaskStore      = @import("./TaskStore.zig");