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|
use std::collections::HashSet;
use std::env::args;
use std::io::{stdin, BufRead, BufReader};
const HELP_MSG: &str = "Title-Case Tool\n\
-h | --help\t\t\tPrints this message\n\
-i | --ignore [word...]\t\tA list of words that should not be corrected";
/// Words that will not be capitalized unless they are at the start or end of a title.
const EXCEPTIONS: &[&str] = &[
"vs", "above", "across", "against", "at", "between", "by", "along", "among", "down", "in",
"once", "around", "of", "off", "on", "to", "with", "before", "behind", "below", "beneath",
"down", "from", "near", "toward", "upon", "within", "a", "an", "the", "and", "but", "for",
"or", "nor", "so", "till", "when", "yet", "that", "than", "in", "into", "like", "onto", "over",
"past", "as", "if",
];
/// Here are the rules:
///
/// - Every line is its own title.
/// - All words are capitalized, except...
/// - Words are not capitalized if they are EXCEPTIONS, unless...
/// - Words are either the first or the last word.
fn main() {
let mut args = args();
args.next(); // ignore self arg
let mut ignorables = HashSet::new();
while let Some(arg) = args.next() {
match arg.as_str() {
"--ignore" | "-i" => {
ignorables = args.collect();
break;
}
"--help" | "-h" => {
println!("{}", HELP_MSG);
return;
}
unrecognized => {
panic!(format!("Unrecognized option: {}", unrecognized));
}
}
}
// gather exceptions
let exceptions: HashSet<&'static str> = EXCEPTIONS.iter().cloned().collect();
// read input and correct lines
for line in BufReader::new(stdin()).lines() {
let line = line.expect("IO error");
println!("{}", correct_line(&line, &ignorables, &exceptions));
}
}
/// Corrects a single line (title) based on placement and exceptions.
fn correct_line(
line: &str,
ignorables: &HashSet<String>,
exceptions: &HashSet<&'static str>,
) -> String {
let mut line = line.split_whitespace().peekable();
let mut result = String::new();
if let Some(first) = line.next() {
// always correct the first word
result.push_str(&correct_word(first, true, ignorables, exceptions));
} else {
// skip empty lines
return result;
}
// handle every other word
while let Some(word) = line.next() {
result.push(' ');
result.push_str(&correct_word(
word,
line.peek().is_none(),
ignorables,
exceptions,
));
}
result
}
/// Corrects a single word based on exceptions and ignorables.
fn correct_word(
word: &str,
first_or_last: bool,
ignorables: &HashSet<String>,
exceptions: &HashSet<&'static str>,
) -> String {
if ignorables.iter().any(|s| s == word) {
// leave ignorables untouched
word.to_owned()
} else if first_or_last || !exceptions.contains(&word.to_lowercase().as_str()) {
// capitalize words that are first, last, or aren't exceptions
capitalize_word(&word.to_lowercase())
} else {
// lowercase all other words
word.to_lowercase()
}
}
/// Capitalizes the first letter of a single word.
fn capitalize_word(word: &str) -> String {
let mut chars = word.chars();
if let Some(first) = chars.next() {
// uppercase first character and append the rest
first.to_uppercase().chain(chars).collect()
} else {
// handle empty words
String::new()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_capitalize_word() {
assert_eq!(capitalize_word("word"), String::from("Word"));
assert_eq!(capitalize_word("as"), String::from("As"));
}
#[test]
fn test_correct_word() {
assert_eq!(
correct_word(
"Like",
false,
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("like")
);
assert_eq!(
correct_word(
"like",
false,
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("like")
);
assert_eq!(
correct_word(
"like",
true,
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("Like")
);
assert_eq!(
correct_word(
"liKe",
false,
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("like")
);
assert_eq!(
correct_word("computers", false, &HashSet::new(), &HashSet::new()),
String::from("Computers")
);
}
#[test]
fn test_correct_line() {
assert_eq!(
correct_line(
"this is a test",
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("This Is a Test")
);
assert_eq!(
correct_line(
"similEs: lIke Or As",
&HashSet::new(),
&EXCEPTIONS.iter().cloned().collect()
),
String::from("Similes: like or As")
);
}
#[test]
fn test_proper_nouns_acronyms() {
let mut ignorables = HashSet::new();
ignorables.insert(String::from("FreeBSD"));
assert_eq!(
correct_line("FreeBSD", &ignorables, &HashSet::new()),
String::from("FreeBSD")
);
}
#[test]
fn test_empty_lines() {
assert_eq!(
correct_line("", &HashSet::new(), &HashSet::new()),
String::from(""),
);
}
}
|
