530 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			530 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
pub enum Closure(P, D = Any, S = Any) -> T {
 | 
						|
    Read(ReadClosure), // reads self (where Self is Closure) and/or environment
 | 
						|
    ReadRef(ReadRefClosure), // reads environment/self, return value tied to closure
 | 
						|
    Mut(MutClosure), // mutates self/environment
 | 
						|
    MutRef(MutRefClosure), // mutates self/environment, return value tied to closure
 | 
						|
    Cons(ConsClosure), // consumes self/environment
 | 
						|
}
 | 
						|
 | 
						|
class Foo(bar: Bar) {}
 | 
						|
 | 
						|
class Bar(mut i: Int) {}
 | 
						|
 | 
						|
fn readClosure(cl: Closure(Int) -> String) -> String {
 | 
						|
    cl(42)
 | 
						|
}
 | 
						|
 | 
						|
fn useReadClosure() {
 | 
						|
    let s = readClosure { i ->
 | 
						|
        'i: ' + i.toString()
 | 
						|
    }
 | 
						|
    assertEq('i: 42', s)
 | 
						|
}
 | 
						|
 | 
						|
fn mutClosure(cl: mut Closure(Int) -> String) -> String {
 | 
						|
    cl(42)
 | 
						|
}
 | 
						|
 | 
						|
fn useMutClosure() {
 | 
						|
    let mut x = 0
 | 
						|
    let cl: mut Closure(Int) -> String = mut { i ->
 | 
						|
        let result = 'Val: ' + (i + x)
 | 
						|
        x++
 | 
						|
        result
 | 
						|
    }
 | 
						|
    let s0 = mutClosure cl
 | 
						|
    assertEq('Val: 42', s0)
 | 
						|
    let s1 = mutClosure cl
 | 
						|
    assertEq('Val: 43', s1)
 | 
						|
}
 | 
						|
 | 
						|
fn consClosure(cl: cons Closure(Int) -> String) -> String {
 | 
						|
    cl(42)
 | 
						|
    // cl(43) // Error! cl was already consumed
 | 
						|
}
 | 
						|
 | 
						|
fn useConsClosure() {
 | 
						|
    let foo = Foo(Bar(10))
 | 
						|
    let cl: cons Closure(Int) -> String = cons { i ->
 | 
						|
        let fooBarI = foo.bar.i
 | 
						|
        drop(foo)
 | 
						|
        'Val: ' + (i + fooBarI)
 | 
						|
    }
 | 
						|
    let s = consClosure(cl)
 | 
						|
    // let err0 = consClosure(cl) // Error! cl may have been consumed
 | 
						|
    // let err1 = foo // Error! foo may have been consumed
 | 
						|
    assertEq('Val: 52', s)
 | 
						|
}
 | 
						|
 | 
						|
fn readRefClosure(cl: Closure(foo: Foo) -> Bar ref foo) -> Int {
 | 
						|
    let foo = Foo(Bar(42))
 | 
						|
    let bar = cl(foo)
 | 
						|
    bar.i
 | 
						|
}
 | 
						|
 | 
						|
fn useReadRefClosure() {
 | 
						|
    let i = readRefClosure { foo -> foo.bar }
 | 
						|
    assertEq(42, i)
 | 
						|
}
 | 
						|
 | 
						|
fn mutRefClosure(cl: mut Closure(foo: Foo) -> Bar ref foo) -> Int {
 | 
						|
    let foo = Foo(Bar(42))
 | 
						|
    let bar = cl(foo)
 | 
						|
    bar.i
 | 
						|
}
 | 
						|
 | 
						|
fn useMutRefClosure() {
 | 
						|
    let i = mutRefClosure mut { foo ->
 | 
						|
        foo.bar.i = 84
 | 
						|
        foo.bar
 | 
						|
    }
 | 
						|
    assertEq(84, i)
 | 
						|
}
 | 
						|
 | 
						|
fn readClosureWithDelegate(cl: Closure(P = Int, D = Foo) -> String) -> String {
 | 
						|
    cl(42)
 | 
						|
}
 | 
						|
 | 
						|
fn useReadClosureWithDelegate() {
 | 
						|
    let foo = Foo(Bar(42))
 | 
						|
    let cl = { i: Int ->
 | 
						|
        'Val: ' + (i + bar.i) // bar found in delegate
 | 
						|
    }
 | 
						|
    cl.delegate = &foo
 | 
						|
    let s = readClosureWithDelegate(cl)
 | 
						|
    assertEq('Val: 84', s)
 | 
						|
}
 | 
						|
 | 
						|
class Baz(foo: Foo) {}
 | 
						|
 | 
						|
fn mutRefClosureWithDelegate(baz: &mut Baz, cl: Closure(Int, baz: &mut Baz)(D = Foo) -> &Bar ref baz) -> String {
 | 
						|
    let foo = Foo(Bar(1))
 | 
						|
    cl.delegate = &foo
 | 
						|
    let bar = cl(2, baz)
 | 
						|
    'Val: ' + bar.i
 | 
						|
}
 | 
						|
 | 
						|
fn useMutRefClosureWithDelegate() {
 | 
						|
    let cl: Closure(Int, baz: &mut Baz)(D = Foo) -> &Bar ref baz = mut { i, baz ->
 | 
						|
        let iFromDelegate = bar.i
 | 
						|
        baz.foo.bar.i = iFromDelegate + i
 | 
						|
        &baz.foo.bar
 | 
						|
    }
 | 
						|
    let baz = Baz(Foo(Bar(20)))
 | 
						|
    let bar = mutRefClosureWithDelegate(cl)
 | 
						|
    assertEq(3, bar.i)
 | 
						|
}
 | 
						|
 | 
						|
fn mutClosureWithDelegate(cl: Closure(P = (Int, Int), D = mut Foo) -> String {
 | 
						|
    let foo = Foo(Bar(42))
 | 
						|
    cl.delegate = &mut foo
 | 
						|
    cl(1, 2)
 | 
						|
}
 | 
						|
 | 
						|
fn useMutClosureWithDelegate() {
 | 
						|
    let cl: Closure(P = (Int, Int), D = mut Foo) -> String = mut { x, y ->
 | 
						|
        bar.i = 3
 | 
						|
        'Val: ' + (x + y + bar.i)
 | 
						|
    }
 | 
						|
    let s = mutClosureWithDelegate(cl)
 | 
						|
    assertEq('Val: 6', s)
 | 
						|
}
 | 
						|
 | 
						|
pub int ClosureBase {
 | 
						|
    params: Array<ClosureParam>
 | 
						|
    mut resolutionStrategy: ResolutionStrategy
 | 
						|
    ref fn getDelegate() -> Option<&Any>
 | 
						|
    ref fn getSelfObject() -> Option<&Any>
 | 
						|
}
 | 
						|
 | 
						|
pub enum ResolutionStrategy {
 | 
						|
    DelegateFirst,
 | 
						|
    DelegateOnly,
 | 
						|
    SelfFirst,
 | 
						|
    SelfOnly,
 | 
						|
    None
 | 
						|
}
 | 
						|
 | 
						|
pub int ConsClosure<T> : ClosureBase {
 | 
						|
    mut fn setDelegate(d: Any) -> Void
 | 
						|
    mut fn setSelf(s: Any) -> Void
 | 
						|
    mut fn call(...args: Array<Any>) -> T
 | 
						|
    def mut op () (...args: Array<Any) -> T = call(...args)
 | 
						|
}
 | 
						|
 | 
						|
pub int MutClosure<T> : ClosureBase {
 | 
						|
    mut fn setDelegate(d: &mut Any) -> Void
 | 
						|
    mut fn setSelf(s: &mut Any) -> Void
 | 
						|
    mut fn call(...args: Array<Any>) -> T
 | 
						|
    def mut op () (...args: Array<Any>) -> T = call(...args)
 | 
						|
}
 | 
						|
 | 
						|
pub int MutRefClosure<T> : ClosureBase {
 | 
						|
    mut fn setDelegate(d: &mut Any) -> Void
 | 
						|
    mut fn setSelf(s: &mut Any) -> Void
 | 
						|
    mut ref fn call(...args: Array<Any>) -> T // T ref self
 | 
						|
    def mut ref op () (...args: Array<Any>) -> T = call(...args)
 | 
						|
}
 | 
						|
 | 
						|
pub int ReadClosure<T> : ClosureBase {
 | 
						|
    mut fn setDelegate(d: &Any) -> Void
 | 
						|
    mut fn setSelf(s: &Any) -> Void
 | 
						|
    fn call(...args: Array<Any>) -> T
 | 
						|
    def op () (...args: Array<Any>) -> T = call(...args)
 | 
						|
}
 | 
						|
 | 
						|
pub int ReadRefClosure<T> : ClosureBase {
 | 
						|
    mut fn setDelegate(d: &Any) -> Void
 | 
						|
    mut fn setSelf(s: &Any) -> Void
 | 
						|
    ref fn call(...args: Array<Any>) -> T
 | 
						|
    def op () (...args) -> T = call(..args)
 | 
						|
}
 | 
						|
 | 
						|
pub int ClosureParam {
 | 
						|
    clazz: Class<Any>
 | 
						|
    def op typeof () -> Class<Any> = clazz
 | 
						|
}
 | 
						|
 | 
						|
// Example of how closures are compiled
 | 
						|
 | 
						|
fn main() {
 | 
						|
    let is = [1, 2, 3]
 | 
						|
    let cl0 = { acc: String, i: Int ->
 | 
						|
        acc + i
 | 
						|
    }
 | 
						|
    println is.reduce(cl0)
 | 
						|
 | 
						|
    let x = 10
 | 
						|
    let cl1 = /* read */ { acc: String, i: Int ->
 | 
						|
        acc + (i + x)
 | 
						|
    }
 | 
						|
    println is.reduce(cl1)
 | 
						|
 | 
						|
    let mut counter = 0
 | 
						|
    let cl2 = mut { acc: String, i: Int ->
 | 
						|
        let result = acc + (i + counter)
 | 
						|
        counter++
 | 
						|
        result
 | 
						|
    }
 | 
						|
    println is.reduce(cl2)
 | 
						|
 | 
						|
    let mut foo = Foo(Bar(1))
 | 
						|
    let cl3 = cons { acc: String, i: Int ->
 | 
						|
        // do something pointless just for illustration
 | 
						|
        if foo.bar.y % 2 == 0 {
 | 
						|
            foo.bar = Bar(1)
 | 
						|
        }
 | 
						|
        let result = acc + (i + foo.bar.y)
 | 
						|
        foo.bar.y++
 | 
						|
        result
 | 
						|
    }
 | 
						|
    // foo.bar = Bar(42) // Error! foo moved into consuming cl3
 | 
						|
    println [1, 2, 3, 4].reduce(cl3) // "11243645"
 | 
						|
}
 | 
						|
 | 
						|
// Compiled
 | 
						|
 | 
						|
@Synthetic
 | 
						|
fn closure_main_cl0(acc: String, i: Int) = acc + i
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_main_cl1_env(x: &Int) -> String {}
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_main_cl1(env: Closure_main_cl1_env) : ReadClosure<String> {
 | 
						|
    impl fn call(...args: Array<Any>) -> String {
 | 
						|
        let acc: String = args[0]
 | 
						|
        let i: Int = args[1]
 | 
						|
        let x: Int = *env.x // because env.getX() -> &&Int
 | 
						|
        acc + (i + x)
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_main_cl2_env(counter: &mut Int) {}
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_main_cl2(env: Closure_main_cl2_env) : MutClosure<String> {
 | 
						|
    impl mut fn call(...args: Array<Any>) -> String {
 | 
						|
        let acc: String = args[0]
 | 
						|
        let i: Int = args[1]
 | 
						|
        let counter = &mut env.counter
 | 
						|
        let result = acc + (i + counter)
 | 
						|
        *counter++
 | 
						|
        result
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_main_cl3(mut foo: Foo) : ConsClosure<String> {
 | 
						|
    impl mut fn call(...args: Array<Any>) -> String {
 | 
						|
        let acc: String = args[0]
 | 
						|
        let i: Int = args[1]
 | 
						|
        if foo.bar.y % 3 == 0 {
 | 
						|
            foo.bar = Bar(1)
 | 
						|
        }
 | 
						|
        let result = acc + (i + foo.bar.y)
 | 
						|
        foo.bar.y++
 | 
						|
        result
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    let is: List<Int> = ArrayList() {
 | 
						|
        add 1
 | 
						|
        add 2
 | 
						|
        add 3
 | 
						|
    }
 | 
						|
    let cl0 = &closure_main_cl0
 | 
						|
    println is.reduce(cl0)
 | 
						|
 | 
						|
    let x = 10
 | 
						|
    let cl1_env = HashMap() {
 | 
						|
        put 'x', &x
 | 
						|
    }
 | 
						|
    let cl1: Closure<String> = Closure::ReadClosure(Closure_main_cl1(cl1_env))
 | 
						|
    println is.reduce(cl1)
 | 
						|
 | 
						|
    let mut counter = 0
 | 
						|
    let cl2_env = Closure_main_cl2_env(&counter)
 | 
						|
    let cl2: Closure<String> = Closure::MutClosure(Closure_main_cl2(cl2_env))
 | 
						|
    println is.reduce(cl2)
 | 
						|
 | 
						|
    let mut foo = Foo(Bar(1))
 | 
						|
    let cl3: Closure<String> = Closure::ConsClosure(Closure_main_cl3(foo)) // foo moved into closure
 | 
						|
    let tmp0: List<Int> = ArrayList() {
 | 
						|
        addAll 1, 2, 3, 4
 | 
						|
    }
 | 
						|
    println tmp0.reduce(cl3)
 | 
						|
}
 | 
						|
 | 
						|
// Example
 | 
						|
 | 
						|
// original
 | 
						|
class Foo {
 | 
						|
    mut fld current = 0
 | 
						|
 | 
						|
    ref fn getClosure(base: Int) -> (mut Closure(Int) -> Int) {
 | 
						|
        return mut { given ->
 | 
						|
            let result = base + given + current
 | 
						|
            current++
 | 
						|
            result
 | 
						|
        }
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    let foo = Foo()
 | 
						|
    let cl = foo.getClosure(10)
 | 
						|
    let nums = [cl(1), cl(2), cl(3), cl(4)]
 | 
						|
    assertEq([11, 13, 15, 17], nums)
 | 
						|
}
 | 
						|
 | 
						|
// Compiles to
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_Foo_getClosure_0(base: &Int, current: &mut Int) : MutClosure(Int) -> Int {
 | 
						|
    impl mut fn call(given: Int) -> Int {
 | 
						|
        let result = *base + given + *current
 | 
						|
        *current++
 | 
						|
        result
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
class Foo {
 | 
						|
    mut fld current = 0
 | 
						|
 | 
						|
    ref fn getClosure(base: Int) -> (mut Closure(Int) -> Int) {
 | 
						|
        return Closure_Foo_getClosure_0(&base, &mut current)
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    /* ... */
 | 
						|
}
 | 
						|
 | 
						|
// Library code
 | 
						|
 | 
						|
pub int ReadClosure(P : () = ())<T, D = Any, S = Any> : Into[Self(P)<T, D, S>, Option<D>] {
 | 
						|
    mut fn setDelegate(d: D) -> Void
 | 
						|
    ref fn getDelegate() -> Option<&D>
 | 
						|
    mut fn setSelfObject(s: &S) -> Void
 | 
						|
    ref fn getSelfObject() -> Option<&S>
 | 
						|
    fn call(...params: P) -> T
 | 
						|
    def op () (...params: P) -> T = call(...params)
 | 
						|
 | 
						|
    def cons fn intoDelegate() -> D {
 | 
						|
        Into[Self(P)<T, D, S>, Option<D>].into()
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
pub abstract class AbstractReadClosure(P : () = ())<T, D = Any, S = Any> : ReadClosure(P)<T, D, S> {
 | 
						|
    mut fld delegate: Option<D>
 | 
						|
    mut fld selfObject: Option<&S>
 | 
						|
 | 
						|
    impl mut fn setDelegate(d: D) {
 | 
						|
        delegate = Some(d)
 | 
						|
    }
 | 
						|
 | 
						|
    impl ref fn getDelegate() -> Option<&D> {
 | 
						|
        &delegate is Some(d) ? Some(d) : None
 | 
						|
    }
 | 
						|
 | 
						|
    impl mut fn setSelfObject(s: &S) {
 | 
						|
        selfObject = Some(s)
 | 
						|
    }
 | 
						|
 | 
						|
    impl ref fn getSelfObject() -> Option<&S> {
 | 
						|
        &selfObject is Some(s) ? Some(s) : None
 | 
						|
    }
 | 
						|
 | 
						|
    impl Into[Self(P)<T, D, S>, D] {
 | 
						|
        cons fn into() -> Option<D> = delegate
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
// User code demonstration
 | 
						|
 | 
						|
class Foo(bar: Bar) {}
 | 
						|
 | 
						|
class Bar(num: Int) {}
 | 
						|
 | 
						|
class Baz(foo: Foo) {
 | 
						|
    pub ref fn getClosure() -> Closure<Int, D = Foo> {
 | 
						|
        return { foo.bar.num + bar.num }
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    let baz0 = Baz(Foo(Bar(1)))
 | 
						|
    let cl = baz0.getClosure()
 | 
						|
    let delegate = Foo(Bar(2))
 | 
						|
    cl.delegate = delegate
 | 
						|
    let result0 = cl()
 | 
						|
    assertEq(3, result0)
 | 
						|
    let baz1 = Baz(Foo(Bar(2)))
 | 
						|
    cl.selfObject = &baz1
 | 
						|
    let result1 = cl()
 | 
						|
    assertEq(4, result1)
 | 
						|
    let movedDelegate = cl.intoDelegate()
 | 
						|
    assertEq(2, movedDelegate.bar.num)
 | 
						|
}
 | 
						|
 | 
						|
// User code compiles to
 | 
						|
 | 
						|
class Foo(bar: Bar) {}
 | 
						|
 | 
						|
class Bar(num: Int) {}
 | 
						|
 | 
						|
@Synthetic
 | 
						|
class Closure_Baz_getClosure_0: AbstractReadClosure()<Int, D = Foo> {
 | 
						|
    ctor(selfObject: &Baz) ref selfObject {
 | 
						|
        self.selfObject = Some(selfObject)
 | 
						|
    }
 | 
						|
 | 
						|
    fn call() -> Int {
 | 
						|
        let t0 = selfObject.unwrap().foo.bar.num
 | 
						|
        let t1 = self.delegate.unwrap().bar.num
 | 
						|
        t0 + t1
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
class Baz(foo: Foo) {
 | 
						|
    pub ref fn getClosure() -> Closure<Int, D = Foo> {
 | 
						|
        return Closure_Baz_getClosure_0(&self)
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    // ...
 | 
						|
}
 | 
						|
 | 
						|
// fn vs Closure syntax
 | 
						|
 | 
						|
int FnOrClosureTaker {
 | 
						|
    fn read(f: fn (Int) -> Int) -> Int
 | 
						|
    fn mut(f: mut fn (Int) -> Int) -> Int
 | 
						|
    fn cons(f: cons fn (Int) -> Int) -> Int
 | 
						|
}
 | 
						|
 | 
						|
class FnOrClosureTakerImpl : FnOrClosureTaker {
 | 
						|
    impl fn read(f: fn (Int) -> Int) {
 | 
						|
        let i0 = f(0)
 | 
						|
        let i1 = f(1)
 | 
						|
        let i2 = f(2)
 | 
						|
        i0 + i1 + i2
 | 
						|
    }
 | 
						|
 | 
						|
    impl fn mut(f: mut fn (Int) -> Int) {
 | 
						|
        /* same as read */
 | 
						|
    }
 | 
						|
 | 
						|
    impl fn cons(f: cons fn (Int) -> Int) {
 | 
						|
        let i0 = f()
 | 
						|
        // let i1 = f() // Error! f already consumed
 | 
						|
        i0
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
mod User {
 | 
						|
    fn getReader() -> fn (Int) -> Int {
 | 
						|
        return { it * 2 }
 | 
						|
    }
 | 
						|
 | 
						|
    fn useReader() {
 | 
						|
        let reader = getReader()
 | 
						|
        let fnOrClosureTaker: FnOrClosureTaker = FnOrClosureTakerImpl()
 | 
						|
        let result = fnOrClosureTaker.read(reader)
 | 
						|
        assertEq(6, result)
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
// compiles to
 | 
						|
 | 
						|
mod User {
 | 
						|
    fn getReader_closure_0(it: Int) -> Int {
 | 
						|
        it * 2
 | 
						|
    }
 | 
						|
 | 
						|
    fn getReader() -> &fn (Int) -> Int {
 | 
						|
        &getReader_closure_0
 | 
						|
    }
 | 
						|
 | 
						|
    // etc.
 | 
						|
}
 | 
						|
 | 
						|
// New interfaces?
 | 
						|
 | 
						|
pub int ReadClosure(P : () = ())<D> -> T : fn (P) -> T {
 | 
						|
    ref fn getDelegate() -> Option<&D>
 | 
						|
    mut fn setDelegate(d: D) -> Void
 | 
						|
    fn call(...p: P) -> T
 | 
						|
    def op () alias call
 | 
						|
}
 | 
						|
 | 
						|
pub int Iterator<T> {
 | 
						|
    mut fn next() -> Option<T>
 | 
						|
}
 | 
						|
 | 
						|
pub int Iterable<T> : Into[Self<T>, Iterator<T>] {
 | 
						|
    ref fn iterator() -> Iterator<&T>
 | 
						|
 | 
						|
    def cons fn intoIterator() = Into[Self, Iterator].into(self)
 | 
						|
}
 | 
						|
 | 
						|
pub class MyIterable : Iterable<Int> {
 | 
						|
    fld items: List<Int> = [1, 2, 3]
 | 
						|
 | 
						|
    impl ref fn iterator() -> Iterator<&Int> {
 | 
						|
        let mut index = 0
 | 
						|
        return mut {
 | 
						|
            if index >= items.length {
 | 
						|
                None
 | 
						|
            } else {
 | 
						|
                let next = items[index]
 | 
						|
                index++
 | 
						|
                Some(next)
 | 
						|
            }
 | 
						|
        }
 | 
						|
    }
 | 
						|
} |