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author | Jordan Gong <jordan.gong@protonmail.com> | 2020-09-08 20:47:03 +0800 |
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committer | Jordan Gong <jordan.gong@protonmail.com> | 2020-09-08 20:47:03 +0800 |
commit | 003e092786221abaef21e197a810f40b1cc9b57f (patch) | |
tree | 298ee86e2ac51a610c4c450ff482c068a2dc2878 /minigrep-improved/src/lib.rs | |
parent | 66e7b9956833678a7911abc362031774f31ed211 (diff) |
Improve minigrep with iterators
Diffstat (limited to 'minigrep-improved/src/lib.rs')
-rw-r--r-- | minigrep-improved/src/lib.rs | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/minigrep-improved/src/lib.rs b/minigrep-improved/src/lib.rs new file mode 100644 index 0000000..b849ed1 --- /dev/null +++ b/minigrep-improved/src/lib.rs @@ -0,0 +1,96 @@ +use std::env; +use std::error::Error; +use std::fs; + +pub struct Config { + pub query: String, + pub filename: String, + pub case_sensitive: bool, +} + +impl Config { + pub fn new(mut args: env::Args) -> Result<Config, &'static str> { + args.next(); + + let query = match args.next() { + Some(arg) => arg, + None => return Err("Didn't get a query string"), + }; + + let filename = match args.next() { + Some(arg) => arg, + None => return Err("Didn't get a file name"), + }; + + let case_sensitive = env::var("CASE_INSENSITIVE").is_err(); + + Ok(Config { + query, + filename, + case_sensitive, + }) + } +} + +pub fn run(config: Config) -> Result<(), Box<dyn Error>> { + let contents = fs::read_to_string(config.filename)?; + + let results = if config.case_sensitive { + search(&config.query, &contents) + } else { + search_case_insensitive(&config.query, &contents) + }; + + for line in results { + println!("{}", line); + } + + Ok(()) +} + +pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> { + contents + .lines() + .filter(|line| line.contains(query)) + .collect() +} + +pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> { + let query = query.to_lowercase(); + + contents + .lines() + .filter(|line| line.to_lowercase().contains(&query)) + .collect() +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn case_sensitive() { + let query = "duct"; + let contents = "\ +Rust: +safe, fast, productive. +Pick three."; + + assert_eq!(vec!["safe, fast, productive."], search(query, contents)); + } + + #[test] + fn case_insensitive() { + let query = "rUsT"; + let contents = "\ +Rust: +safe, fast, productive. +Pick three. +Trust me."; + + assert_eq!( + vec!["Rust:", "Trust me."], + search_case_insensitive(query, contents) + ); + } +} |