bdd0e96d78
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).
107 lines
2.4 KiB
Plaintext
107 lines
2.4 KiB
Plaintext
#import "modules/std.sx";
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#import "modules/math/math.sx";
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#import "modules/compiler.sx";
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#import "modules/test.sx";
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pkg :: #import "modules/testpkg";
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add :: (a: s32, b: s32) -> s32 { a + b }
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mul :: (a: s32, b: s32) -> s32 { a * b }
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identity :: (x: $T) -> T { x }
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pair_add :: (a: $T, b: $U) -> s64 {
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cast(s64) a + cast(s64) b
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}
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typed_sum :: (..args: []s32) -> s32 {
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result := 0;
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for args: (it) { result = result + it; }
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result
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}
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apply :: (f: (s32, s32) -> s32, x: s32, y: s32) -> s32 {
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f(x, y)
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}
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void_return :: () {
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return;
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}
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implicit_return :: (x: s32) -> s32 {
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x * 2
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}
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early_return :: (x: s32) -> s32 {
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if x > 10 { return 99; }
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x
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}
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main :: () {
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// ========================================================
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// 5. FUNCTIONS & DECLARATIONS
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// ========================================================
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print("=== 5. Functions ===\n");
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// Constant binding
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FORTY_TWO :: 42;
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print("const: {}\n", FORTY_TWO);
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// Typed constant
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TYPED_PI : f64 : 3.14;
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print("typed-const: {}\n", TYPED_PI);
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// Variable with default init
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di : s32;
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print("default-init: {}\n", di);
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// Implicit return
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print("implicit-ret: {}\n", implicit_return(21));
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// Explicit return
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print("early-ret: {}\n", early_return(5));
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print("early-ret2: {}\n", early_return(20));
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// Void return
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void_return();
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print("void-return: ok\n");
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// Generic — single param
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print("generic-s32: {}\n", identity(42));
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print("generic-f32: {}\n", identity(1.5));
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print("generic-bool: {}\n", identity(true));
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// Generic — multiple params
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print("generic-multi: {}\n", pair_add(10, 20));
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// Lambda
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double :: (x: s32) => x * 2;
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print("lambda: {}\n", double(7));
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// Lambda with return type
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halve :: (x: f32) -> f32 => x / 2.0;
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print("lambda-ret: {}\n", halve(10.0));
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// Local function (non-lambda)
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local_add :: (a: s32, b: s32) -> s32 { a + b }
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print("local-fn: {}\n", local_add(3, 4));
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// Nested function calls
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print("fn-nested: {}\n", add(mul(2, 3), mul(4, 5)));
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// Variadic (typed)
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print("varargs: {}\n", typed_sum(1, 2, 3, 4, 5));
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// Spread
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spread_arr : [3]s32 = .[10, 20, 30];
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print("spread: {}\n", typed_sum(..spread_arr));
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// Function pointers
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fp : (s32, s32) -> s32 = add;
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print("fp: {}\n", fp(3, 4));
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fp = mul;
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print("fp-reassign: {}\n", fp(3, 4));
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print("fp-apply: {}\n", apply(add, 10, 20));
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}
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