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/* * Copyright © 2019 Gianmarco Garrisi * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ //! This crate lets you write an iterator into a LinesWriter, with each item on a line. //! //! The trait is implemented for all the types that implement `std::io::Write`. //! Simply call write_lines on the writer and pass an iterator as argument. //! //! # Examples //! //! ```rust //! use lines_writer::LinesWriter; //! //! fn main() { //! let str = "This is\na string\nto show\nhow do\nthis work"; //! std::io::stdout().write_lines(str.lines()).unwrap(); //! } //! ``` //! //! ```rust //! use lines_writer::LinesWriter; //! //! fn main() { //! let array = [10, 15, 63, 29]; //! std::io::stdout().write_lines(&array).unwrap(); //! } //! ``` use std::io::{Result, Write}; use std::fmt::Display; /// This trait lets you write an iterator into its implementor with each item on a line. pub trait LinesWriter { /// write the items of the iterator onto self fn write_lines<I>(&mut self, iterator: I) -> Result<usize> where I: IntoIterator, I::Item: Display; } impl<T> LinesWriter for T where T: Write { fn write_lines<I>(&mut self, iterator: I) -> Result<usize> where I: IntoIterator, I::Item: Display { let mut res = 0; for el in iterator { writeln!(self, "{}", el)?; res+=1; } Ok(res) } } #[cfg(test)] mod tests { #[test] fn test() { use crate::LinesWriter; let str = "This is\na string\nto test\nthe trait implementation"; let n = std::io::stdout().write_lines(str.lines()).unwrap(); assert_eq!(n, 4); } }