Rust State Monad

gistfile1.txt

/Users/ulyssecarion/rust/sparsile/src/lib.rs:7:9: 13:10 error: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
/Users/ulyssecarion/rust/sparsile/src/lib.rs:7         State {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8             runState: |firstState| {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:9                 let (result, nextState) = (self.runState)(firstState);
/Users/ulyssecarion/rust/sparsile/src/lib.rs:10
/Users/ulyssecarion/rust/sparsile/src/lib.rs:11                 (f(result).runState)(nextState)
/Users/ulyssecarion/rust/sparsile/src/lib.rs:12             }
                                                ...
/Users/ulyssecarion/rust/sparsile/src/lib.rs:6:65: 14:6 note: first, the lifetime cannot outlive the block at 6:64...
/Users/ulyssecarion/rust/sparsile/src/lib.rs:6     fn and_then<B>(&self, f: |A| -> State<S, B>) -> State<S, B> {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:7         State {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8             runState: |firstState| {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:9                 let (result, nextState) = (self.runState)(firstState);
/Users/ulyssecarion/rust/sparsile/src/lib.rs:10
/Users/ulyssecarion/rust/sparsile/src/lib.rs:11                 (f(result).runState)(nextState)
                                                ...
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8:23: 12:14 note: ...so that closure does not outlive its stack frame
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8             runState: |firstState| {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:9                 let (result, nextState) = (self.runState)(firstState);
/Users/ulyssecarion/rust/sparsile/src/lib.rs:10
/Users/ulyssecarion/rust/sparsile/src/lib.rs:11                 (f(result).runState)(nextState)
/Users/ulyssecarion/rust/sparsile/src/lib.rs:12             }
/Users/ulyssecarion/rust/sparsile/src/lib.rs:6:65: 14:6 note: but, the lifetime must be valid for the anonymous lifetime #1 defined on the block at 6:64...
/Users/ulyssecarion/rust/sparsile/src/lib.rs:6     fn and_then<B>(&self, f: |A| -> State<S, B>) -> State<S, B> {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:7         State {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8             runState: |firstState| {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:9                 let (result, nextState) = (self.runState)(firstState);
/Users/ulyssecarion/rust/sparsile/src/lib.rs:10
/Users/ulyssecarion/rust/sparsile/src/lib.rs:11                 (f(result).runState)(nextState)
                                                ...
/Users/ulyssecarion/rust/sparsile/src/lib.rs:7:9: 13:10 note: ...so that expression is assignable (expected `State<'_, S, B>`, found `State<'_, S, B>`)
/Users/ulyssecarion/rust/sparsile/src/lib.rs:7         State {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:8             runState: |firstState| {
/Users/ulyssecarion/rust/sparsile/src/lib.rs:9                 let (result, nextState) = (self.runState)(firstState);
/Users/ulyssecarion/rust/sparsile/src/lib.rs:10
/Users/ulyssecarion/rust/sparsile/src/lib.rs:11                 (f(result).runState)(nextState)
/Users/ulyssecarion/rust/sparsile/src/lib.rs:12             }
                                                ...
e

lib.rs

struct State<'a, S, A> {
    runState: |S|: 'a -> (A, S)
}

impl<'a, S, A> State<'a, S, A> {
    fn and_then<B>(&self, f: |A| -> State<S, B>) -> State<S, B> {
        State {
            runState: |firstState| {
                let (result, nextState) = (self.runState)(firstState);

                (f(result).runState)(nextState)
            }
        }
    }
}