diff options
Diffstat (limited to 'src/test/ui/run-pass/array-slice-vec/vec-matching-fold.rs')
| -rw-r--r-- | src/test/ui/run-pass/array-slice-vec/vec-matching-fold.rs | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/test/ui/run-pass/array-slice-vec/vec-matching-fold.rs b/src/test/ui/run-pass/array-slice-vec/vec-matching-fold.rs new file mode 100644 index 00000000000..1a30f875580 --- /dev/null +++ b/src/test/ui/run-pass/array-slice-vec/vec-matching-fold.rs @@ -0,0 +1,56 @@ +// Copyright 2014 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(slice_patterns)] + +use std::fmt::Debug; + +fn foldl<T, U, F>(values: &[T], + initial: U, + mut function: F) + -> U where + U: Clone+Debug, T:Debug, + F: FnMut(U, &T) -> U, +{ match values { + &[ref head, ref tail..] => + foldl(tail, function(initial, head), function), + &[] => { + // FIXME: call guards + let res = initial.clone(); res + } + } +} + +fn foldr<T, U, F>(values: &[T], + initial: U, + mut function: F) + -> U where + U: Clone, + F: FnMut(&T, U) -> U, +{ + match values { + &[ref head.., ref tail] => + foldr(head, function(tail, initial), function), + &[] => { + // FIXME: call guards + let res = initial.clone(); res + } + } +} + +pub fn main() { + let x = &[1, 2, 3, 4, 5]; + + let product = foldl(x, 1, |a, b| a * *b); + assert_eq!(product, 120); + + let sum = foldr(x, 0, |a, b| *a + b); + assert_eq!(sum, 15); +} |
