Basic controller impl., some file reordering

src/graph/system.zig

@@ -0,0 +1,35 @@
+const std = @import("std");
+const utils = @import("utils.zig");
+const Controller = @import("resource.zig").Controller;
+
+function_runner: *const fn ([]const *anyopaque) void,
+requested_types: []const Request,
+
+pub const Request = union(enum) {
+    resource: utils.Hash,
+    controller: void,
+    // TODO:
+    // - Params
+};
+
+const Self = @This();
+pub fn from_function(comptime function: anytype, alloc: std.mem.Allocator) !Self {
+    utils.validate_system(function);
+
+    var requests: [@typeInfo(@TypeOf(function)).Fn.params.len]Request = undefined;
+    inline for (0.., @typeInfo(@TypeOf(function)).Fn.params) |i, param| {
+        switch (@typeInfo(param.type.?).Pointer.child) {
+            Controller => requests[i] = .controller,
+            else => |resource_type| requests[i] = .{ .resource = utils.hash_type(resource_type) },
+        }
+    }
+
+    return Self{
+        .requested_types = try alloc.dupe(Request, &requests),
+        .function_runner = utils.generate_runner(function),
+    };
+}
+
+pub fn deinit(self: *const Self, alloc: std.mem.Allocator) void {
+    alloc.free(self.requested_types);
+}