X-Git-Url: https://piware.de/gitweb/?p=learn-rust.git;a=blobdiff_plain;f=src%2Fmain.rs;h=06d122b9c4c727f399d8273312ffcfb2a95088fd;hp=c07c4051165861365a2176a3c1edec6957d16903;hb=105f3ee65d6d52bdeddda90afde8ebfcacc416e8;hpb=dad4fd7e6684ffa911c1298e374a56d63a56710e diff --git a/src/main.rs b/src/main.rs index c07c405..06d122b 100644 --- a/src/main.rs +++ b/src/main.rs @@ -1,9 +1,11 @@ mod word_utils; +mod lib; use std::collections::HashMap; use std::io::{prelude::*, ErrorKind}; use std::fs::{self, File}; +use lib::*; use word_utils::{first_word, second_word}; fn test_strings() { @@ -63,19 +65,12 @@ fn test_hashmaps() { println!("scores after doubling: {:?}", scores); // double scores of immutable hashmap (rebuild it) - let collect_scores: HashMap<_, _> = collect_scores.iter() + let collect_scores: HashMap<_, _> = collect_scores.into_iter() .map(|(k, v)| (k, 2 * v)) .collect(); println!("collect_scores after rebuilding with doubling: {:?}", collect_scores); } -fn read_file(path: &str) -> Result { - let mut s = String::new(); - File::open(path)? - .read_to_string(&mut s)?; - Ok(s) -} - fn test_files() { if let Ok(mut f) = File::open("Cargo.toml") { let mut contents = String::new(); @@ -116,9 +111,90 @@ fn test_files() { } } +fn test_generics() { + let num_list = vec![3, 42, -7, 100, 0]; + println!("largest number: {}", largest(&num_list)); + println!("num_list: {:?}", num_list); + + let char_list = vec!['a', 'y', 'q', 'm']; + println!("largest char: {}", largest(&char_list)); + + let str_list = vec!["hello", "world", "blue", "planet"]; + println!("largest str: {}", largest(&str_list)); + println!("str_list: {:?}", str_list); + + let string_list = vec!["aaaa".to_string(), "xxxxx".to_string(), "ffff".to_string()]; + println!("largest string (with cloning): {}", largest_clone(&string_list)); + println!("largest string (with ref): {}", largest_ref(&string_list)); + println!("string_list: {:?}", string_list); + + let s1 = String::from("abcd"); + let l; + { + let s2 = "efghi"; + l = longest(&s1, s2); + } + println!("longest string: {}", l); +} + +fn test_closures() { + let mut expensive_int_result = Cacher::new(|x| { + println!("calculating expensive int result for {}", x); + 2 * x + }); + + println!("1st int call for value 1: {}", expensive_int_result.value(1)); + println!("2nd int call for value 1: {}", expensive_int_result.value(1)); + println!("1st int call for value 2: {}", expensive_int_result.value(2)); + + let mut expensive_str_result = Cacher::new(|x: &str| { + println!("calculating expensive str result for {}", x); + x.len() + }); + + println!("1st int call for value abc: {}", expensive_str_result.value("abc")); + println!("2nd int call for value abc: {}", expensive_str_result.value("abc")); + println!("1st int call for value defg: {}", expensive_str_result.value("defg")); +} + +fn test_iterators() { + let v1 = vec!["Hello", "good", "world"]; + // implied default is .into_iter() which consumes v1 + for s in v1.iter() { + println!("element: {}", s); + } + // can still use it now + println!("v1: {:?}", &v1); + + // manual iteration + let mut v1_iter = v1.iter(); + while let Some(e) = v1_iter.next() { + println!("while loop over iter: {}", e); + } + + for l_element in v1.iter().filter(|x| x.contains('l')) { + println!("v1 element containing 'l': {}", l_element); + } + + let v2 = vec![1, 2, 3]; + let double_v2: Vec<_> = v2.iter().map(|x| x * 2).collect(); + println!("doubled v2: {:?}", double_v2); + + for i in v2.into_iter().map(|x| x * 3) { + println!("for loop triplicating v2: {}", i); + } + + for i in Counter5::new() { + println!("Counter 5 value: {}", i); + } +} + fn main() { test_strings(); test_vectors(); test_hashmaps(); test_files(); + test_generics(); + test_closures(); + test_iterators(); }