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|
pub fn process_escapes(input: &str) -> String {
if input.len() < 1 {
return String::from(input);
}
let mut v = Vec::from(input);
for i in 0..(v.len() - 1) {
if v[i] == '\\' as u8 && is_escapable(v[i + 1] as char) {
v.remove(i);
v[i] = char_to_escape_sequence(v[i] as char) as u8;
}
}
String::from_utf8(v).unwrap()
}
fn char_to_escape_sequence(chr: char) -> char {
match chr {
'n' => '\n',
't' => '\t',
'r' => '\r',
'\\' => '\\',
'0' => '\0',
_ => chr,
}
}
fn is_escapable(chr: char) -> bool {
match chr {
'n' | 't' | 'r' | '\\' | '0' => true,
_ => false,
}
}
#[cfg(test)]
mod tests {
use super::*;
mod test_process_escapes {
use super::*;
#[test]
fn test_newline() {
assert_eq!(
String::from("hello\nworld"),
process_escapes(r#"hello\nworld"#)
);
}
#[test]
fn test_carriage_return() {
assert_eq!(
String::from("hello\rworld"),
process_escapes(r#"hello\rworld"#)
);
}
#[test]
fn test_tab() {
assert_eq!(
String::from("hello\tworld"),
process_escapes(r#"hello\tworld"#)
);
}
#[test]
fn test_backslash() {
assert_eq!(
String::from("hello\\world"),
process_escapes(r#"hello\\world"#)
);
}
#[test]
fn test_null() {
assert_eq!(
String::from("hello\0world"),
process_escapes(r#"hello\0world"#)
);
}
}
mod test_char_to_escape_sequence {
use super::*;
#[test]
fn test_escape_n() {
assert_eq!('\n', char_to_escape_sequence('n'));
}
#[test]
fn test_escape_t() {
assert_eq!('\t', char_to_escape_sequence('t'));
}
#[test]
fn test_escape_r() {
assert_eq!('\r', char_to_escape_sequence('r'));
}
#[test]
fn test_escape_backslash() {
assert_eq!('\\', char_to_escape_sequence('\\'));
}
#[test]
fn test_escape_0() {
assert_eq!('\0', char_to_escape_sequence('0'));
}
}
mod is_escapable_tests {
use super::*;
#[test]
fn test_escape_n() {
assert!(is_escapable('n'));
}
#[test]
fn test_escape_t() {
assert!(is_escapable('t'));
}
#[test]
fn test_escape_r() {
assert!(is_escapable('r'));
}
#[test]
fn test_escape_backslash() {
assert!(is_escapable('\\'));
}
#[test]
fn test_escape_0() {
assert!(is_escapable('0'));
}
}
}
|
