only support void hooks

src/nu/hooks.zig

@@ -2,10 +2,10 @@ const std = @import("std");
 
 pub fn Hook(ftype: type) type {
     const F: std.builtin.Type.Fn = @typeInfo(ftype).Fn;
-    const Result: type = F.return_type.?;
+    const R: std.builtin.Type = @typeInfo(F.return_type.?);
+    comptime if (R != .Void) @compileError("Hook signature must return void.");
 
-    return switch (@typeInfo(Result)) {
+    return struct {
-        .Void => struct {
         const Self = @This();
 
         handlers: std.AutoArrayHashMap(*const ftype, void),
@@ -33,38 +33,6 @@ pub fn Hook(ftype: type) type {
                 @call(.auto, handler, args);
             }
         }
-        },
-        else => struct {
-            const Self = @This();
-
-            handlers: std.AutoArrayHashMap(*const ftype, void),
-
-            pub fn init(alloc: std.mem.Allocator) Self {
-                return Self{
-                    .handlers = std.AutoArrayHashMap(*const ftype, void).init(alloc),
-                };
-            }
-
-            pub fn deinit(self: *Self) void {
-                self.handlers.deinit();
-            }
-
-            pub fn register(self: *Self, f: ftype) !void {
-                try self.handlers.putNoClobber(f, {});
-            }
-
-            pub fn unregister(self: *Self, f: ftype) void {
-                _ = self.handlers.orderedRemove(f);
-            }
-
-            pub fn invoke(self: Self, alloc: std.mem.Allocator, args: anytype) ![]Result {
-                const results = try alloc.alloc(Result, self.handlers.count());
-                for (self.handlers.keys(), results) |handler, *result| {
-                    result.* = @call(.auto, handler, args);
-                }
-                return results;
-            }
-        },
     };
 }
 
@@ -112,83 +80,3 @@ test "void hooks" {
     set_flags.invoke(.{&flag});
     try std.testing.expect(flag == 0b00);
 }
-
-test "collect hooks" {
-    var collect = Hook(fn (usize) usize).init(std.testing.allocator);
-    defer collect.deinit();
-
-    const hooks = struct {
-        pub fn double(f: usize) usize {
-            return f * 2;
-        }
-
-        pub fn square(f: usize) usize {
-            return f * f;
-        }
-    };
-
-    {
-        const result = try collect.invoke(std.testing.allocator, .{3});
-        defer std.testing.allocator.free(result);
-        try std.testing.expectEqualSlices(usize, &.{}, result);
-    }
-
-    try collect.register(hooks.double);
-
-    {
-        const result = try collect.invoke(std.testing.allocator, .{4});
-        defer std.testing.allocator.free(result);
-        try std.testing.expectEqualSlices(usize, &.{8}, result);
-    }
-
-    try collect.register(hooks.square);
-
-    {
-        const result = try collect.invoke(std.testing.allocator, .{5});
-        defer std.testing.allocator.free(result);
-        try std.testing.expectEqualSlices(usize, &.{ 10, 25 }, result);
-    }
-
-    collect.unregister(hooks.double);
-
-    {
-        const result = try collect.invoke(std.testing.allocator, .{6});
-        defer std.testing.allocator.free(result);
-        try std.testing.expectEqualSlices(usize, &.{36}, result);
-    }
-
-    collect.unregister(hooks.square);
-
-    {
-        const result = try collect.invoke(std.testing.allocator, .{7});
-        defer std.testing.allocator.free(result);
-        try std.testing.expectEqualSlices(usize, &.{}, result);
-    }
-}
-
-test "error_hooks" {
-    const CollectError = error{Fail};
-    const Collect = Hook(fn (usize) CollectError!usize);
-    var collect = Collect.init(std.testing.allocator);
-    defer collect.deinit();
-
-    const hooks = struct {
-        pub fn halve(f: usize) !usize {
-            if (f % 2 == 0) return f / 2;
-            return CollectError.Fail;
-        }
-
-        pub fn third(f: usize) !usize {
-            if (f % 3 == 0) return f / 3;
-            return CollectError.Fail;
-        }
-    };
-
-    try collect.register(hooks.halve);
-    try collect.register(hooks.third);
-
-    const result = try collect.invoke(std.testing.allocator, .{4});
-    defer std.testing.allocator.free(result);
-    try std.testing.expectEqual(2, try result[0]);
-    try std.testing.expectError(CollectError.Fail, result[1]);
-}