40 lines
1.2 KiB
Rust
40 lines
1.2 KiB
Rust
/** Serene --- Yet an other Lisp
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*
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* Copyright (c) 2020 Sameer Rahmani <lxsameer@gnu.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/// Seq trait describes a seqable collection. Please note that `first`
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/// and `rest` return a copy of the data not the reference!
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pub trait Seq<T> {
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type Coll;
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fn first(&self) -> Option<T>;
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fn rest(&self) -> Self::Coll;
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}
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// pub fn first<'a, T, S: Seq<T>>(coll: impl Into<Option<&'a S>>) -> Option<&'a T>
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// where
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// S: 'a,
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// {
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// coll.into().and_then(first)
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// }
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// pub fn rest<'a, T, S: Seq<T>>(coll: impl Into<Option<&'a S>>) -> S {
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// match coll.into() {
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// Some(e) => e.rest(),
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// None =>
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// }
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// }
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