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sx/examples/basic/0040-basic-block-value.sx
agra 66bdc70bf1 test: group examples into per-category folders
Move examples/*.sx and their expected/ snapshots into per-category
subfolders (examples/<category>/...). Folder = leading filename token,
with ffi-objc/ffi-jni kept whole; filenames are unchanged. The corpus
runner and LSP sweep now discover each category's expected/ dir, while
issues/ stays flat. Example 1058's repo-root-relative companion import
is made file-relative. Path strings embedded in 164 snapshots were
regenerated (path-only changes). Test-layout docs in CLAUDE.md updated.
2026-06-21 14:41:34 +03:00

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// Block value rule: a block's value is 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 "forgot to produce a value".
//
// { … expr } → value is `expr`
// { … expr; } → void (value discarded)
//
// Match arms are exempt: the arm `;` is an arm terminator, so `case .x: expr;`
// still yields `expr` (only an explicit inner braced block follows the rule).
#import "modules/std.sx";
// Implicit return: trailing expression, no `;`.
double :: (n: i32) -> i32 { n * 2 }
// if/else as a value — each branch's last expression has no `;`.
sign :: (n: i32) -> i32 {
if n < 0 { -1 } else if n > 0 { 1 } else { 0 }
}
// A value-producing block bound to a name.
sum3 :: (a: i32, b: i32, c: i32) -> i32 {
t := { x := a + b; x + c }; // block value is `x + c`
t
}
// Match arms keep their `;` (exempt): the arm `;` is an arm terminator, so each
// arm still yields its expression as the match value.
classify :: (n: i32) -> i32 {
if n == {
case 0: 100;
case 1: 10;
else: 7;
}
}
main :: () -> i32 {
total : i32 = 0;
total = total + double(10); // 20
total = total + sign(-7); // -1
total = total + sum3(1, 2, 3); // 6
total = total + classify(1); // 10
print("block-value total: {}\n", total); // 20 - 1 + 6 + 10 = 35
total
}