candid gulch
Hello there.
I want to generate a StaticStringMap at compile time that acts as a kind of "lookup table" for specific functions. This will later be used as routes for a little web framework.
Usage should look something like this:
library.init(.{
.{ "GET /", HomePageHandler },
.{ "GET /user", UserPageHandler },
});
In the init function I generate a Key-Value-List at compile time that I can then later pass to initComptime of StaticStringMap.
const HandlerFn = *const fn (*anyopaque, *anyopaque) *anyopaque;
fn generateKeyValueList(comptime routes: anytype) []struct { []const u8, HandlerFn } {
comptime {
var kv_list: [routes.len]struct { []const u8, HandlerFn } = undefined;
for (routes, 0..) |entry, i| {
const key = entry.@"0";
const value: HandlerFn = entry.@"1";
kv_list[i] = .{ key, value };
}
return &kv_list;
}
}
// ...
const kv_list = generateKeyValueList(routes);
const map = std.StaticStringMap(HandlerFn).initComptime(kv_list);
The problem is:
error: expected type '*const fn (*anyopaque, *anyopaque) *anyopaque', found '*const fn (void, void) []const u8'
const value: HandlerFn = entry.@"1";
~~~~~^~~~~
note: pointer type child 'fn (void, void) []const u8' cannot cast into pointer type child 'fn (*anyopaque, *anyopaque) *anyopaque'
note: return type '[]const u8' cannot cast into return type '*anyopaque'
echo viper