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Runs `go` → "b"

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::NullCoalescing_ChainPicksFirstNonNull   topic: core   status: verified
// verified behavior: Test.go(...) == "b"

namespace Test
func pick(a: string?, b: string?) -> string {
    return a ?? b ?? "fallback"
}
func go() -> string { return pick(nil, "b") }

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::NullConditional_OnPresentReadsMember   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let s: string? = "hello"
    return s?.Length ?? 0
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::Ternary_DrivesCompoundAssign   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var n = 4
    n += n > 0 ? 4 : -4
    return n
}

Runs `go` → "zero"

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::Ternary_Nested   topic: core   status: verified
// verified behavior: Test.go(...) == "zero"

namespace Test
func sign(n: int) -> string {
    return n > 0 ? "pos" : (n < 0 ? "neg" : "zero")
}
func go() -> string { return sign(0) }

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::Ternary_SelectsBranch   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let x = -9
    return x > 0 ? x : 0 - x
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_AccumulatesSum   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var i = 1
    var total = 0
    while i <= 5 {
        total += i
        i += 1
    }
    return total
}

Runs `go` → "aaa"

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_BuildsString   topic: core   status: verified
// verified behavior: Test.go(...) == "aaa"

namespace Test
func go() -> string {
    var s = ""
    var n = 3
    while n > 0 {
        s = s + "a"
        n -= 1
    }
    return s
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_Countdown   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var n = 10
    while n > 0 { n -= 1 }
    return n
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_FalseCondition_NeverRuns   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var n = 99
    while false { n = 0 }
    return n
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_FlagBasedExit   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func firstSquareOver(limit: int) -> int {
    var i = 0
    var done = false
    var answer = -1
    while !done {
        if i * i > limit {
            answer = i
            done = true
        }
        i += 1
    }
    return answer
}
func go() -> int { return firstSquareOver(10) }

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_NestedMultiplicationTable   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var i = 1
    var sum = 0
    while i <= 5 {
        var j = 1
        while j <= 5 {
            sum += i * j
            j += 1
        }
        i += 1
    }
    return sum
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_ControlFlow.cs::While_TrueWithEarlyReturn   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var n = 0
    while true {
        n += 2
        if n >= 8 { return n }
    }
    return -1
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Closure_Accumulator   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var sum = 0
    let addTo = func(value: int) {
        sum = sum + value
    }
    for i in 1..6 {
        addTo(i)
    }
    return sum
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Closure_MutableCapture   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var total = 0
    let inc = func() {
        total = total + 1
    }
    inc()
    inc()
    return total
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Collection_ForInSum   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [1, 2, 3, 4, 5]
    var total = 0
    for x in xs {
        total += x
    }
    return total
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Collection_ListCount   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [1, 2, 3, 4]
    return xs.Count
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Collection_ListLiteralIndex   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [10, 20, 30]
    return xs[0] + xs[1] + xs[2]
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::ExpressionBodied_Function   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func double(x: int) -> int = x * 2
func go() -> int {
    return double(10)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::FunctionPointer_CallThroughLocal   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func add(a: int, b: int) -> int {
    return a + b
}
func go() -> int {
    let p = &add
    return p(3, 4)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Lambda_ArrowExpression   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func apply(x: int, f: Func<int, int>) -> int = f(x)
func go() -> int {
    return apply(6, (x) => x * x)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::NullCoalescing_Fallback   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func find(id: int) -> string? {
    if id == 0 { return nil }
    return "x"
}
func go() -> int {
    let s = find(0) ?? "fallback"
    return s.Length
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::NullConditional_Access   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let s: string? = nil
    return s?.Length ?? 0
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Tuple_Construction   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let t = (3, 4)
    return t.Item1 + t.Item2
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Data.cs::Tuple_DestructuringInLet   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func swap(a: int, b: int) -> (int, int) {
    return (b, a)
}
func go() -> int {
    let (x, y) = swap(2, 3)
    return x + y
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::LetElse_BindsPresentValue   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func lookup(id: int) -> int? {
    if id == 0 { return nil }
    return 50
}
func go() -> int {
    let v = lookup(3) else { return -1 }
    return v
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::LetElse_ChainedGuards   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func first(id: int) -> int? {
    if id < 0 { return nil }
    return 10
}
func second(n: int) -> int? {
    if n == 0 { return nil }
    return n + 5
}
func go() -> int {
    let a = first(2) else { return -1 }
    let b = second(a) else { return -2 }
    return b
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::LetElse_DivertsOnNil   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func lookup(id: int) -> int? {
    if id == 0 { return nil }
    return 50
}
func go() -> int {
    let v = lookup(0) else { return -99 }
    return v
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::LetElse_SecondGuardDiverts   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func first(id: int) -> int? {
    return 0
}
func second(n: int) -> int? {
    if n == 0 { return nil }
    return n + 5
}
func go() -> int {
    let a = first(2) else { return -1 }
    let b = second(a) else { return -2 }
    return b
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::Throw_CaughtByCallerBoundary   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func risky(n: int) -> int {
    if n < 0 { throw InvalidOperationException("negative") }
    return n
}
func go() -> int {
    var result = 0
    try {
        result = risky(-1)
    } catch (Exception e) {
        result = -42
    }
    return result
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::TryCatch_BareCatchSwallows   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var result = 0
    try {
        result = int.Parse("xyz")
    } catch {
        result = -7
    }
    return result
}

Runs `go` → "inner"

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::TryCatch_Nested_InnerHandlesFirst   topic: core   status: verified
// verified behavior: Test.go(...) == "inner"

namespace Test
func go() -> string {
    var tag = "none"
    try {
        try {
            throw FormatException("x")
        } catch (FormatException e) {
            tag = "inner"
        }
    } catch (Exception e) {
        tag = "outer"
    }
    return tag
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::TryCatch_RecoversFromParseFailure   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var result = 0
    try {
        result = int.Parse("notanumber")
    } catch (FormatException e) {
        result = -1
    }
    return result
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::TryCatch_SuccessPathSkipsCatch   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var result = 0
    try {
        result = int.Parse("123")
    } catch (FormatException e) {
        result = -1
    }
    return result
}

Runs `go` → "negative"

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Errors.cs::TryCatch_TypedCatchBindsMessage   topic: core   status: verified
// verified behavior: Test.go(...) == "negative"

namespace Test
func go() -> string {
    var msg = "none"
    try {
        throw InvalidOperationException("negative")
    } catch (InvalidOperationException e) {
        msg = e.Message
    }
    return msg
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Bcl_ListAddSum   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = List<int>()
    xs.Add(1)
    xs.Add(2)
    xs.Add(3)
    var total = 0
    for x in xs {
        total += x
    }
    return total
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Linq_Sum   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [1, 2, 3, 4]
    return xs.Sum()
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::NullableValueLetElse   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func find(id: int) -> int? {
    if id == 0 {
        return nil
    }
    return id * 10
}
func lookup(id: int) -> int {
    let v = find(id) else {
        return 0 - 1
    }
    return v
}
func go() -> int {
    return lookup(5) + lookup(0)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::OutParam_TryParse   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    if int.TryParse("77", out var n) {
        return n
    }
    return 0
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Pointer_ByRefIntMutation   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func addTen(x: *int) {
    x += 10
}
func go() -> int {
    var n = 5
    addTen(&n)
    return n
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Range_IndexFromEnd   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [10, 20, 30]
    return xs[^1]
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Range_IndexFromEnd_Second   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    let xs = [10, 20, 30]
    return xs[^2]
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Recursion_Factorial   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func fact(n: int) -> int {
    if n <= 1 {
        return 1
    }
    return n * fact(n - 1)
}
func go() -> int {
    return fact(5)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::Recursion_Fibonacci   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func fib(n: int) -> int {
    if n < 2 {
        return n
    }
    return fib(n - 1) + fib(n - 2)
}
func go() -> int {
    return fib(7)
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::TryCatch_ConvertsException   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var result = 0
    try {
        result = int.Parse("not a number")
    } catch (Exception e) {
        result = 0 - 1
    }
    return result
}

Compiles

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Misc.cs::TryCatch_Succeeds   topic: core   status: verified
// compiles cleanly (no auto-run claim was extracted)

namespace Test
func go() -> int {
    var result = 0
    try {
        result = int.Parse("123")
    } catch {
        result = 0 - 1
    }
    return result
}

Runs `go` → 3

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Numerics.cs::Algo_CountSetViaModulo   topic: core   status: verified
// verified behavior: Test.go(...) == 3

namespace Test
func countMultiples(limit: int, of: int) -> int {
    var count = 0
    for i in 1..limit {
        if i % of == 0 { count += 1 }
    }
    return count
}
func go() -> int { return countMultiples(10, 3) }

Runs `go` → 55

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Numerics.cs::Algo_FibonacciIterative   topic: core   status: verified
// verified behavior: Test.go(...) == 55

namespace Test
func fib(n: int) -> int {
    var a = 0
    var b = 1
    for i in 0..n {
        let t = a + b
        a = b
        b = t
    }
    return a
}
func go() -> int { return fib(10) }

Runs `go` → 6

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Numerics.cs::Algo_GcdEuclid   topic: core   status: verified
// verified behavior: Test.go(...) == 6

namespace Test
func gcd(a: int, b: int) -> int {
    var x = a
    var y = b
    while y != 0 {
        let t = y
        y = x % y
        x = t
    }
    return x
}
func go() -> int { return gcd(48, 18) }

Runs `go` → true

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Numerics.cs::Algo_IsPrime   topic: core   status: verified
// verified behavior: Test.go(...) == true

namespace Test
func isPrime(n: int) -> bool {
    if n < 2 { return false }
    var d = 2
    while d * d <= n {
        if n % d == 0 { return false }
        d += 1
    }
    return true
}
func go() -> bool { return isPrime(97) }

Runs `go` → 243

// E# — a verified example from the E# language corpus (CLR language; .es, not ECMAScript).
// provenance: ILEmitterTests_Coverage_Numerics.cs::Algo_PowerByMultiplication   topic: core   status: verified
// verified behavior: Test.go(...) == 243

namespace Test
func ipow(b: int, exp: int) -> int {
    var result = 1
    for i in 0..exp {
        result *= b
    }
    return result
}
func go() -> int { return ipow(3, 5) }