dimgigov
3eb1ad3a82
Sessions 18–23 quality work: - B.3c match arm guards + sequential found-flag lower (bootstrap + selfhost) - Generic HOF type inference (Array/Iter map/filter/fold without type args) - Pattern binding shadowing via unique C locals (__pN_src) - Ownership C.2 exclusive &mut data-flow + C.4 goldens; *p= store-through fix - Ownership C.3 auto-drop on early return/branches: scoped defers, move-on-return, Drop monomorphization, materialize return before Drop - LSP 0.3.0: hover from real sema types - Examples and QUALITY_PLAN session log; selfhost-loop identical
84 lines
1.8 KiB
Plaintext
84 lines
1.8 KiB
Plaintext
// Match arm guards: `p if cond => body`
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// Bindings from the pattern are in scope for the guard 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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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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return match n {
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x if x < 0 => -1,
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x if x == 0 => 0,
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x if x > 0 => 1,
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_ => 99
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};
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}
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func Main() -> int {
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// Ident + guard
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Test_AssertEqInt(Classify(-5), -1);
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Test_AssertEqInt(Classify(0), 0);
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Test_AssertEqInt(Classify(7), 1);
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// Literal + guard (second arm only when n is even)
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let n: int = 4;
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let a: int = match n {
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4 if n % 2 == 0 => 40,
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4 => 41,
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_ => -1
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};
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Test_AssertEqInt(a, 40);
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let m: int = 4;
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let b: int = match m {
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4 if m % 2 != 0 => 40,
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4 => 41,
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_ => -1
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};
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Test_AssertEqInt(b, 41);
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// Range + guard
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let k: int = 5;
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let c: int = match k {
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1..10 if k % 2 == 0 => 100,
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1..10 => 101,
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_ => -1
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};
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Test_AssertEqInt(c, 101);
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let j: int = 6;
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let d: int = match j {
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1..10 if j % 2 == 0 => 100,
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1..10 => 101,
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_ => -1
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};
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Test_AssertEqInt(d, 100);
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// Enum payload binding used in guard
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let opt: Option = Option { tag: Option_Some };
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opt.data.Some_0 = 15;
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let e: int = match opt {
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Option::Some(v) if v > 10 => v * 2,
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Option::Some(v) => v,
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Option::None => 0
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};
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Test_AssertEqInt(e, 30);
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let small: Option = Option { tag: Option_Some };
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small.data.Some_0 = 3;
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let f: int = match small {
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Option::Some(v) if v > 10 => v * 2,
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Option::Some(v) => v,
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Option::None => 0
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};
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Test_AssertEqInt(f, 3);
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PrintInt(e);
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PrintLine("");
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Test_Pass("match_guards");
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return 0;
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}
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