mirror of
https://github.com/rust-lang/rust
synced 2024-11-05 20:45:15 +00:00
20 lines
539 B
Rust
20 lines
539 B
Rust
pub enum Expr<'var, VAR> {
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Let(Box<Expr<'var, VAR>>,
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Box<dyn for<'v> Fn(Expr<'v, VAR>) -> Expr<'v, VAR> + 'var>)
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}
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pub fn add<'var, VAR>
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(a: Expr<'var, VAR>, b: Expr<'var, VAR>) -> Expr<'var, VAR> {
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loop {}
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}
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pub fn let_<'var, VAR, F: for<'v> Fn(Expr<'v, VAR>) -> Expr<'v, VAR>>
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(a: Expr<'var, VAR>, b: F) -> Expr<'var, VAR> {
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loop {}
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}
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fn main() {
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let ex = |x| { //~ ERROR type annotations needed
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let_(add(x,x), |y| {
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let_(add(x, x), |x|x)})};
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}
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