Files
sx/examples/190-tuple-values.sx
agra c03db7938c lang 2.4: value-position pack projection xs.value + mixed-tuple type fix
`xs.<method>` over a constrained pack projects a (zero-arg) protocol method
across every element into a tuple: `xs.get` ≈ `(xs[0].get(), …, xs[N-1].get())`.
lowerFieldAccess intercepts `xs.<m>` on a pack base (where <m> is a protocol
method) and synthesizes/lowers `xs[i].<m>()` per element into a tuple_init.
For a parameterised `Box(T)` the projected tuple is heterogeneous (each element
returns its own T). examples/196-pack-value-projection.sx.

Surfaced and fixed a pre-existing bug: inferExprType didn't handle tuple field
access (`t.0` / `t.x`), so a mixed-size tuple like `(42, "hi")` inferred the
string field as s64 — the wrong type then drove a bad `print` pack mangle and
coerced the string to i64 (garbage). Added the tuple arm (numeric + named).
Regression: a `(s64, string)` case in examples/190-tuple-values.sx.
2026-05-29 19:45:49 +03:00

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// Tuple values: construction, element access, struct-field storage,
// return, and operators. Regression for the tuple-construction bug where
// an inferred `:=` tuple literal lowered its element values under the
// enclosing fn's (narrower) return `target_type`, mismatching the
// independently-inferred s64 field types and yielding garbage on read.
#import "modules/std.sx";
Box :: struct { xs: (s32, s32); }
swap :: (a: s64, b: s64) -> (s64, s64) { (b, a); }
fst :: (t: (s64, s64)) -> s64 { t.0; }
main :: () -> s32 {
// Inferred positional tuple + numeric field access.
pair := (40, 2);
print("pair {} {}\n", pair.0, pair.1);
// Named tuple: named + numeric access.
named := (x: 10, y: 20);
print("named {} {} {}\n", named.x, named.0, named.1);
// Element into a typed local (access path, not just print).
a : s64 = pair.0;
b : s64 = pair.1;
print("locals {} {}\n", a, b);
// Tuple-typed struct field: store a tuple value, read both elements.
box : Box = ---;
box.xs = (7, 9);
print("field {} {}\n", box.xs.0, box.xs.1);
// Return a tuple from a function.
s := swap(1, 2);
print("ret {} {}\n", s.0, s.1);
// Pass a tuple by value.
print("pass {}\n", fst((11, 22)));
// Operators: equality, concatenation, repetition, membership, lex.
print("eq {}\n", (1, 2) == (1, 2));
c := (1, 2) + (3, 4);
print("concat {} {}\n", c.0, c.3);
r := (1, 2) * 3;
print("rep {} {}\n", r.0, r.5);
print("mem {}\n", 3 in (1, 2, 3));
print("lex {}\n", (1, 2) < (1, 3));
// Mixed-size fields: a tuple with both an s64 and a string (16-byte fat
// pointer). Field types are tracked per-position, so reading each back is
// typed correctly (s64 prints as a number, string as text).
mixed := (42, "hi");
print("mixed {} {}\n", mixed.0, mixed.1);
0;
}