Files
sx/examples/0026-basic-operators.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

167 lines
3.9 KiB
Plaintext

#import "modules/std.sx";
#import "modules/math/math.sx";
#import "modules/compiler.sx";
#import "modules/test.sx";
pkg :: #import "modules/testpkg";
add :: (a: s32, b: s32) -> s32 { a + b }
mul :: (a: s32, b: s32) -> s32 { a * b }
// P4 edge: Chained default→default calls
Chained :: protocol {
base :: (msg: string) -> s32;
wrap :: (msg: string) -> s32 {
self.base(msg) + 1
}
double_wrap :: (msg: string) -> s32 {
self.wrap(msg) + self.wrap(msg)
}
}
main :: () {
// ========================================================
// 2. OPERATORS & PRECEDENCE
// ========================================================
print("=== 2. Operators ===\n");
// Arithmetic
print("add: {}\n", 3 + 4);
print("sub: {}\n", 10 - 3);
print("mul: {}\n", 6 * 7);
print("div: {}\n", 20 / 4);
print("mod: {}\n", 17 % 5);
print("neg: {}\n", -(5));
// Comparisons
print("eq: {}\n", 5 == 5);
print("neq: {}\n", 5 != 3);
print("lt: {}\n", 3 < 5);
print("gt: {}\n", 5 > 3);
print("le: {}\n", 5 <= 5);
print("ge: {}\n", 5 >= 3);
// Chained comparisons
v := 50;
print("chain: {}\n", 0 <= v <= 100);
print("chain-gt: {}\n", 100 > v > 0);
print("chain-mixed: {}\n", 100 > v >= 0);
// Equality chains
print("eq-chain: {}\n", 5 == 5 == 5);
print("eq-chain-f: {}\n", 5 == 5 == 6);
// Bitwise
print("band: {}\n", 0xFF & 0x0F);
print("bor: {}\n", 1 | 2 | 4);
// Bitwise XOR
print("bxor: {}\n", 0xFF ^ 0x0F);
print("bxor2: {}\n", 6 ^ 3);
// Bitwise NOT
print("bnot: {}\n", ~0);
print("bnot2: {}\n", ~1);
// Shifts
print("shl: {}\n", 1 << 4);
print("shr: {}\n", 256 >> 4);
print("shl2: {}\n", 3 << 3);
print("shr2: {}\n", 255 >> 1);
// Bitwise on variables
bv1 := 0xFF;
bv2 := 0x0F;
print("band-var: {}\n", bv1 & bv2);
bv3 := 1;
bv4 := 6;
print("bor-var: {}\n", bv3 | bv4);
print("bxor-var: {}\n", bv1 ^ bv2);
print("shl-var: {}\n", bv3 << 4);
print("shr-var: {}\n", bv1 >> 4);
print("bnot-var: {}\n", ~bv2);
// Bitwise compound assignment
bca := 0xFF;
bca &= 0x0F;
print("and-assign: {}\n", bca);
bco := 0x0F;
bco |= 0xF0;
print("or-assign: {}\n", bco);
bcx := 0xFF;
bcx ^= 0x0F;
print("xor-assign: {}\n", bcx);
bcs := 1;
bcs <<= 8;
print("shl-assign: {}\n", bcs);
bcr := 256;
bcr >>= 4;
print("shr-assign: {}\n", bcr);
// Modulo on variables
mv1 := 17;
mv2 := 5;
print("mod-var: {}\n", mv1 % mv2);
// Logical (short-circuit)
print("and: {}\n", true and true);
print("and-false: {}\n", true and false);
print("or: {}\n", false or true);
print("or-false: {}\n", false or false);
// Short-circuit verification
print("short-and: {}\n", false and true);
print("short-or: {}\n", true or false);
// Compound assignment
ca := 10;
ca += 5;
print("ca+=: {}\n", ca);
ca -= 3;
print("ca-=: {}\n", ca);
ca *= 2;
print("ca*=: {}\n", ca);
ca /= 6;
print("ca/=: {}\n", ca);
// Precedence
print("prec1: {}\n", 2 + 3 * 4);
print("prec2: {}\n", (2 + 3) * 4);
// xx explicit cast
big2 : f64 = 200.7;
small : u8 = xx big2;
print("xx-cast: {}\n", small);
// Implicit widening conversions
wu : u8 = 200;
ws : s64 = wu;
print("widen-u8-s64: {}\n", ws);
wi3 : s32 = 42;
wf : f64 = wi3;
print("widen-s32-f64: {}\n", wf);
wf32 : f32 = 1.5;
wf64 : f64 = wf32;
print("widen-f32-f64: {}\n", wf64);
wu2 : u8 = 100;
ws2 : s16 = wu2;
print("widen-u8-s16: {}\n", ws2);
// More xx narrowing
xl : s64 = 12345;
xs : s32 = xx xl;
print("xx-s64-s32: {}\n", xs);
xd : f64 = 1.5;
xf : f32 = xx xd;
print("xx-f64-f32: {}\n", xf);
xdf : f64 = 7.9;
xdi : s32 = xx xdf;
print("xx-f64-s32: {}\n", xdi);
}