X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/5baae0ea037ed642b7fe8975fb3004b29827d5b1..ab7f9b241429bd675b437d2437799de75d2f409b:/workspace/src/part14.rs diff --git a/workspace/src/part14.rs b/workspace/src/part14.rs deleted file mode 100644 index fb580f9..0000000 --- a/workspace/src/part14.rs +++ /dev/null @@ -1,108 +0,0 @@ -// Rust-101, Part 14: Slices, Arrays, External Dependencies -// ======================================================== - - -// ## Slices - -pub fn sort(data: &mut [T]) { - if data.len() < 2 { return; } - - // We decide that the element at 0 is our pivot, and then we move our cursors through the rest of the slice, - // making sure that everything on the left is no larger than the pivot, and everything on the right is no smaller. - let mut lpos = 1; - let mut rpos = data.len(); - /* Invariant: pivot is data[0]; everything with index (0,lpos) is <= pivot; - [rpos,len) is >= pivot; lpos < rpos */ - loop { - // **Exercise 14.1**: Complete this Quicksort loop. You can use `swap` on slices to swap two elements. Write a - // test function for `sort`. - unimplemented!() - } - - // Once our cursors met, we need to put the pivot in the right place. - data.swap(0, lpos-1); - - // Finally, we split our slice to sort the two halves. The nice part about slices is that splitting them is cheap: - let (part1, part2) = data.split_at_mut(lpos); - unimplemented!() -} - -// **Exercise 14.2**: Since `String` implements `PartialEq`, you can now change the function `output_lines` in the previous part -// to call the sort function above. If you did exercise 13.1, you will have slightly more work. Make sure you sort by the matched line -// only, not by filename or line number! - -// Now, we can sort, e.g., an vector of numbers. -fn sort_nums(data: &mut Vec) { - sort(&mut data[..]); -} - -// ## Arrays -fn sort_array() { - let mut array_of_data: [f64; 5] = [1.0, 3.4, 12.7, -9.12, 0.1]; - sort(&mut array_of_data); -} - -// ## External Dependencies - - -// I disabled the following module (using a rather bad hack), because it only compiles if `docopt` is linked. -// Remove the attribute of the `rgrep` module to enable compilation. -#[cfg(feature = "disabled")] -pub mod rgrep { - // Now that `docopt` is linked, we can first add it to the namespace with `extern crate` and then import shorter names with `use`. - // We also import some other pieces that we will need. - extern crate docopt; - use self::docopt::Docopt; - use part12::{run, Options, OutputMode}; - use std::process; - - // The `USAGE` string documents how the program is to be called. It's written in a format that `docopt` can parse. - static USAGE: &'static str = " -Usage: rgrep [-c] [-s] ... - -Options: - -c, --count Count number of matching lines (rather than printing them). - -s, --sort Sort the lines before printing. -"; - - // This function extracts the rgrep options from the command-line arguments. - fn get_options() -> Options { - // This parses `argv` and exit the program with an error message if it fails. The code is taken from the [`docopt` documentation](http://burntsushi.net/rustdoc/docopt/).
- let args = Docopt::new(USAGE).and_then(|d| d.parse()).unwrap_or_else(|e| e.exit()); - // Now we can get all the values out. - let count = args.get_bool("-c"); - let sort = args.get_bool("-s"); - let pattern = args.get_str(""); - let files = args.get_vec(""); - if count && sort { - println!("Setting both '-c' and '-s' at the same time does not make any sense."); - process::exit(1); - } - - // We need to make the strings owned to construct the `Options` instance. - let mode = if count { - OutputMode::Count - } else if sort { - OutputMode::SortAndPrint - } else { - OutputMode::Print - }; - Options { - files: files.iter().map(|file| file.to_string()).collect(), - pattern: pattern.to_string(), - output_mode: mode, - } - } - - // Finally, we can call the `run` function from the previous part on the options extracted using `get_options`. Edit `main.rs` to call this function. - // You can now use `cargo run -- ` to call your program, and see the argument parser and the threads we wrote previously in action! - pub fn main() { - unimplemented!() - } -} - -// **Exercise 14.3**: Wouldn't it be nice if rgrep supported regular expressions? There's already a crate that does all the parsing and matching on regular -// expression, it's called [regex](https://crates.io/crates/regex). Add this crate to the dependencies of your workspace, add an option ("-r") to switch -// the pattern to regular-expression mode, and change `filter_lines` to honor this option. The documentation of regex is available from its crates.io site. -// (You won't be able to use the `regex!` macro if you are on the stable or beta channel of Rust. But it wouldn't help for our use-case anyway.) -