+++ /dev/null
-// Rust-101, Part 14: Slices, Arrays, External Dependencies
-// ========================================================
-
-
-// ## Slices
-
-pub fn sort<T: PartialOrd>(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<i32>) {
- 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 part13::{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] <pattern> <file>...
-
-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/). <br/>
- 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("<pattern>");
- let files = args.get_vec("<file>");
- 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 -- <pattern> <files>` 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.)
-
projects / rust-101.git / blobdiff