Files
sx/examples/0518-packs-pack-value-dispatch.sx
agra 4e942b5373 test: migrate examples to XXXX-category-name layout + split expected streams
Rename all example tests/companions to the XXXX-category-test-name scheme
(per-category 100-blocks: basic 0010, types 0100, ... errors 1000,
diagnostics 1100, ffi 1200, ffi-objc 1300, ffi-jni 1400, vectors 1500,
platform 1600). Companions and dir/C fixtures move in lockstep with their
parent test; #import/#source/#include paths rewritten to match.

Expected output now lives in examples/expected/ (a sibling dir of the
tests) split into three streams per the new convention:
  <name>.exit / <name>.stdout / <name>.stderr  (+ optional <name>.ir)

run_examples.sh rewritten: scans examples/ and issues/ for an
expected/<name>.exit marker, captures stdout and stderr separately (no
more 2>&1), compares each stream + exit + optional IR snapshot.

Behavior validated unchanged: every renamed test reproduces its prior
merged output + exit (diffs limited to file paths/basenames embedded in
diagnostics + traces, which correctly reflect the new names). Suite:
292 passed, 0 failed. 50-smoke.sx split + issue relocation + docs follow
in subsequent commits.
2026-06-01 19:05:15 +03:00

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// 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;
}