// Variadic heterogeneous type packs — step 4 source-construction
// path: `$args[$i]` in expression position yields a comptime Type
// VALUE (`Value.type_tag(TypeId)` in the interp). Lets builders +
// pack-fn bodies dispatch on the i-th pack type at compile time.
//
// Two usage shapes covered here:
//
// 1. `type_name($args[0])` — the value-form Type goes through the
//    reflection intrinsic, picking up the per-mono concrete type.
//
// 2. `inline if type_eq($args[0], s64) { ... }` — compile-time
//    branch over the pack element's type. The fold via
//    `tryConstBoolCondition` reads $args[0] via `resolveTypeArg`,
//    which the step-4 work taught to walk `pack_arg_types`.
//
// Lowering: `$args[$i]` in expression position emits a
// `const_type(arg_types[i])` IR op. The interp materialises a
// `Value.type_tag(TypeId)`. LLVM emit bails (Type is comptime-only).

#import "modules/std.sx";

show :: (..$args) -> string => type_name($args[0]);

describe :: (..$args) -> string {
    inline if type_eq($args[0], s64) { return "got s64"; }
    inline if type_eq($args[0], string) { return "got string"; }
    inline if type_eq($args[0], bool) { return "got bool"; }
    return "got other";
}

main :: () -> s32 {
    // type_name picks up the per-mono first-arg type.
    print("{}\n", show(42));         // s64
    print("{}\n", show("hi"));        // string
    print("{}\n", show(3.14));        // f64

    // inline-if + type_eq picks the right branch per mono.
    print("{}\n", describe(42));      // got s64
    print("{}\n", describe("hello"));  // got string
    print("{}\n", describe(true));     // got bool
    print("{}\n", describe(3.14));     // got other

    return 0;
}
