dimgigov
f9185c96b2
Blocks can yield a value: last expression statement is the result.
Match arms accept block bodies, so multi-statement arms work:
match n {
1 => { let a = 10; a + 1 },
_ => 0
}
Bootstrap: lowerBlock(asExpr) lifts the trailing skExpr. Selfhost: parse
{...} as ekBlock, emit __blk_N yield temps (retTypeKind -2), and treat
only non-empty strValue as match/block yield. Nested enum/struct pattern
bindings recurse in both compilers.
Example: match_block.bux. Selfhost-loop remains binary-identical.
82 lines
1.6 KiB
Plaintext
82 lines
1.6 KiB
Plaintext
// Multi-stmt match arms (block bodies) + block-as-expression
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import Std::Io::{PrintLine, PrintInt};
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import Std::Test::{Test_AssertEqInt, Test_Pass};
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struct Point {
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x: int,
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y: int,
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}
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enum Option {
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Some(int),
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None
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}
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func Classify(n: int) -> int {
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match n {
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1 => {
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let a: int = 10;
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a + 1
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},
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2 => {
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PrintLine("two");
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let b: int = 20;
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b * 2
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},
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_ => 0
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}
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}
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func Main() -> int {
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Test_AssertEqInt(Classify(1), 11);
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Test_AssertEqInt(Classify(2), 40);
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Test_AssertEqInt(Classify(9), 0);
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// Block as expression outside match
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let r: int = {
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let x: int = 5;
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let y: int = 6;
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x + y
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};
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Test_AssertEqInt(r, 11);
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// Tuple pattern + block body
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let t: (int, int) = (3, 4);
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let u: int = match t {
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(a, b) => {
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let prod: int = a * b;
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prod
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},
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_ => 0
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};
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Test_AssertEqInt(u, 12);
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// Struct pattern + block body
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let p: Point = Point { x: 2, y: 5 };
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let z: int = match p {
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Point { x: px, y: py } => {
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let sum: int = px + py;
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sum
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},
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_ => -1
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};
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Test_AssertEqInt(z, 7);
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// Enum payload + block
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let opt: Option = Option { tag: Option_Some };
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opt.data.Some_0 = 7;
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let v: int = match opt {
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Option::Some(n) => {
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let doubled: int = n + n;
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doubled
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},
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Option::None => 0
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};
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Test_AssertEqInt(v, 14);
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PrintInt(Classify(2));
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PrintLine("");
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Test_Pass("match_block");
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return 0;
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}
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