Files
sx/examples/0121-types-types.sx
agra bdd0e96d78 feat(lang): block value requires no trailing ; (Rust-style)
A block's value is now its last statement ONLY when that statement is a
trailing expression with no `;`. A trailing `;` discards the value,
leaving the block void. This makes value-vs-statement explicit and lets
the compiler reject "this block was supposed to produce a value".

Compiler:
- Parser records `Block.produces_value` (last stmt is a no-`;` trailing
  expression) + `Block.discarded_semi` (the `;` that discarded a value),
  via `expectSemicolonAfter`. A trailing expression before `}` may now
  omit its `;` (previously a parse error). Match-arm and else-arm bodies
  are built value-producing regardless of the arm `;` (arms are exempt —
  the `;` is an arm terminator).
- Lowering: `lowerBlockValue` / the block-expr path / `inferExprType`
  respect `produces_value`. A value-position block that discards its value
  is a hard error (`lowerValueBody` for function bodies; the value-context
  `.block` path for if/else branches, `catch` bodies, value bindings,
  match arms). Pure-failable `-> !` bodies (value rides the error channel)
  and a value-if whose branches are void are handled without false errors.
- `defer`/`onfail` cleanup bodies lower as statements (void), so a
  trailing `;` there is fine.

Migration (behavior-preserving — output unchanged):
- stdlib + ~210 examples: dropped the trailing `;` on value-position last
  expressions. `format` now ends with an explicit `#insert "return
  result;"` (it relied on `#insert`-as-block-value, which `;` discards).
- Two `main :: () -> s32` examples that relied on the old silent
  default-return got an explicit trailing `0`.
- Rejection snapshots 0412 / 1013 regenerated (their quoted source lines
  lost a `;`); the diagnostics themselves are unchanged.

Docs/tests: specs.md "Block values" section; examples 0040 (rules) + 0041
(rejection); 3 parser unit tests. Filed issue 0066 (pre-existing
match-arm negated-literal phi-width quirk, surfaced not caused here).

Gates: zig build, zig build test, run_examples.sh -> 343 passed,
cross_compile.sh -> 7 passed (also refreshed its stale example names).
2026-06-02 09:23:50 +03:00

343 lines
8.2 KiB
Plaintext

#import "modules/std.sx";
#import "modules/math/math.sx";
#import "modules/compiler.sx";
#import "modules/test.sx";
pkg :: #import "modules/testpkg";
Point :: struct { x, y: s32; }
Color :: enum { red; green; blue; }
Shape :: enum {
circle: f32;
rect: struct { w, h: f32; };
none;
}
Overlay :: union {
f: f32;
i: s32;
}
Vec2 :: union {
data: [2]f32;
struct { x, y: f32; };
}
Defaults :: struct {
a: s32;
b: s32 = 99;
c: s32 = ---;
}
MyFloat :: f64;
Status :: enum u8 { ok; err; timeout; }
add :: (a: s32, b: s32) -> s32 { a + b }
mul :: (a: s32, b: s32) -> s32 { a * b }
vec3 :: (x: f32, y: f32, z: f32) -> Vector(3, f32) {
.[x, y, z]
}
// Global variable for address-of test
g_smoke_val : s32 = 42;
write_to_ptr :: (p: *s32) {
p.* = 99;
}
main :: () {
// ========================================================
// 3. TYPE SYSTEM
// ========================================================
print("=== 3. Types ===\n");
// Primitive types
v_s8 : s8 = 127;
v_s16 : s16 = 32000;
v_s32 : s32 = 100000;
v_u8 : u8 = 255;
v_u16 : u16 = 65000;
v_u32 : u32 = 4000000;
print("s8: {}\n", v_s8);
print("s16: {}\n", v_s16);
print("s32: {}\n", v_s32);
print("u8: {}\n", v_u8);
print("u16: {}\n", v_u16);
print("u32: {}\n", v_u32);
// Type alias
mf : MyFloat = 1.5;
print("alias: {}\n", mf);
// --- Structs ---
// Positional literal
p1 : Point = .{ 1, 2 };
print("struct-pos: {}\n", p1);
// Type-prefix literal
p2 := Point.{ 3, 4 };
print("struct-prefix: {}\n", p2);
// Named fields
p3 := Point.{ y=10, x=20 };
print("struct-named: {}\n", p3);
// Shorthand (variable name = field name)
x : s32 = 5;
y : s32 = 6;
p4 := Point.{ x, y };
print("struct-shorthand: {}\n", p4);
// Field defaults
d1 : Defaults;
print("defaults: a={} b={}\n", d1.a, d1.b);
// Field access and assignment
p5 := Point.{ 0, 0 };
p5.x = 42;
p5.y = 99;
print("field-assign: {}\n", p5);
// --- Enum (payload-less) ---
ec : Color = .red;
print("enum: {}\n", ec);
// Enum comparison
ce1 : Color = .red;
ce2 : Color = .red;
ce3 : Color = .blue;
print("enum-eq: {}\n", ce1 == ce2);
print("enum-neq: {}\n", ce1 != ce3);
// Backing type
st : Status = .err;
print("backing: {}\n", st);
// --- Enum (tagged union) ---
sh : Shape = .circle(3.14);
print("tagged: {}\n", sh);
// Payload access
radius := sh.circle;
print("payload: {}\n", radius);
// Void variant
sh = .none;
print("void-variant: {}\n", sh);
// Variant reassignment
sh = .circle(1.0);
print("reassign: {}\n", sh);
sh = .rect(.{ 5, 3 });
print("reassign2: {}\n", sh);
// Type-prefix construction
tp := Shape.circle(2.5);
print("enum-prefix: {}\n", tp);
// Pattern matching
sh2 : Shape = .rect(.{ 5, 3 });
if sh2 == {
case .circle: print("match: circle\n");
case .rect: print("match: rect\n");
case .none: print("match: none\n");
}
// Match as expression
sh3 : Shape = .circle(1.0);
ms := if sh3 == {
case .circle: 10;
case .rect: 20;
case .none: 30;
}
print("match-expr: {}\n", ms);
// Match expression with else
me_val := 42;
me_res := if me_val == {
case 1: 10;
case 2: 20;
else: 99;
}
print("match-expr-else: {}\n", me_res);
// Payload capture (block form)
sh4 : Shape = .circle(9.5);
if sh4 == {
case .circle: (r) { print("capture: {}\n", r); }
case .rect: (sz) { print("capture: {}\n", sz); }
case .none: print("capture: none\n");
}
// Payload capture (arrow form)
sh_ca : Shape = .circle(7.5);
if sh_ca == {
case .circle: (r) => print("capture-arrow: {}\n", r);
case .rect: (sz) => print("capture-arrow: rect\n");
case .none: print("capture-arrow: none\n");
}
// else arm in match
num := 42;
if num == {
case 1: print("else-match: one\n");
case 2: print("else-match: two\n");
else: print("else-match: other\n");
}
// Integer pattern matching
code := 2;
if code == {
case 1: print("int-match: one\n");
case 2: print("int-match: two\n");
case 3: print("int-match: three\n");
}
// Integer match with else
im_code := 99;
if im_code == {
case 1: print("int-match-else: one\n");
case 2: print("int-match-else: two\n");
else: print("int-match-else: unknown\n");
}
// Bool pattern matching
bm := true;
if bm == {
case true: print("bool-match-t: yes\n");
case false: print("bool-match-t: no\n");
}
bm2 := false;
if bm2 == {
case true: print("bool-match-f: yes\n");
case false: print("bool-match-f: no\n");
}
// Bool conditional
flag := true;
if flag { print("bool: true\n"); }
// --- Union (untagged) ---
o : Overlay = ---;
o.f = 3.14;
print("union-f: {}\n", o.f);
// Type punning — read same bits as s32
print("union-i: {}\n", o.i);
// Union member promotion
uv : Vec2 = ---;
uv.x = 1.0;
uv.y = 2.0;
print("promoted-x: {}\n", uv.x);
print("promoted-data0: {}\n", uv.data[0]);
// --- Arrays ---
arr : [5]s32 = .[10, 20, 30, 40, 50];
print("arr[2]: {}\n", arr[2]);
print("arr.len: {}\n", arr.len);
// Array element assignment
aa : [3]s32 = .[1, 2, 3];
aa[1] = 99;
print("arr-assign: {}\n", aa);
// --- Slices ---
sl : []s32 = .[1, 2, 3, 4, 5];
print("sl[0]: {}\n", sl[0]);
print("sl.len: {}\n", sl.len);
// Slice element write
sla : []s32 = .[10, 20, 30];
sla[1] = 55;
print("sl-assign: {}\n", sla);
// Subslicing
sub := arr[1..4];
print("sub: {}\n", sub);
head := arr[..3];
print("head: {}\n", head);
tail := arr[2..];
print("tail: {}\n", tail);
// Slice of slice
sos : []s32 = .[10, 20, 30, 40, 50];
mid := sos[1..4];
inner := mid[0..2];
print("slice-of-slice: {}\n", inner);
// String subslicing
msg := "hello world";
print("strsub: {}\n", msg[6..11]);
print("str-prefix: {}\n", msg[..5]);
print("str-suffix: {}\n", msg[6..]);
// --- Pointers ---
// Address-of global variable
write_to_ptr(@g_smoke_val);
print("global-addr-of: {}\n", g_smoke_val);
pv := Point.{ 10, 20 };
ptr := @pv;
print("deref: {}\n", ptr.*);
// Auto-deref
print("auto-deref: {}\n", ptr.x);
// Many-pointer
mp : [*]s32 = @arr[0];
print("mp[0]: {}\n", mp[0]);
print("mp[3]: {}\n", mp[3]);
// Many-pointer write
mpw : [5]s32 = .[10, 20, 30, 40, 50];
mpw_ptr : [*]s32 = @mpw[0];
mpw_ptr[2] = 99;
print("mp-write: {}\n", mpw[2]);
// Pointer-null comparison
np : *s32 = null;
print("ptr==null: {}\n", np == null);
print("ptr!=null: {}\n", np != null);
np2 := @pv.x;
print("ptr2==null: {}\n", np2 == null);
print("ptr2!=null: {}\n", np2 != null);
// Pointer to nested struct field
Inner3 :: struct { a: f32; b: f32; c: f32; }
Outer3 :: struct { key: s32; inner: Inner3; }
out3 := Outer3.{ key = 42, inner = Inner3.{ a = 1.0, b = 2.0, c = 3.0 } };
ip3 := @out3.inner;
print("ptr-nested-field: {} {} {}\n", ip3.a, ip3.b, ip3.c);
// Store to many-pointer field must not corrupt adjacent memory
MpHolder :: struct { items: [*]s64; sentinel: s64; }
mph := MpHolder.{ items = xx 0, sentinel = 42 };
mph.items = xx 0;
print("mp-store-sentinel: {}\n", mph.sentinel);
// --- Vectors ---
vc := vec3(1, 3, 2);
print("vec-construct: {}\n", vc);
va := vec3(1, 2, 3);
vb := vec3(4, 5, 6);
print("vec-add: {}\n", va + vb);
print("vec-sub: {}\n", vec3(5, 5, 5) - vec3(1, 2, 3));
print("vec-mul: {}\n", vec3(2, 3, 4) * vec3(1, 2, 3));
print("vec-div: {}\n", vec3(10, 9, 8) / vec3(2, 3, 4));
print("vec-scalar: {}\n", vec3(1, 3, 2) * 2.0);
print("vec-neg: {}\n", -vec3(1, 3, 2));
ve := vec3(10, 20, 30);
print("vec-x: {}\n", ve.x);
print("vec-y: {}\n", ve.y);
print("vec-z: {}\n", ve.z);
print("vec-idx: {}\n", ve[1]);
}