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use encoder::{AsciiEncoder, Utf8Encoder};
use decoder::{AsciiDecoder, Utf8Decoder};
use DecodeError;
use std::ascii::AsciiExt;
const INVALID_INDEX: u8 = 0xFF;
pub trait Alphabet {
fn encode(&self, input: &[u8]) -> String;
fn decode(&self, input: &str) -> Result<Vec<u8>, DecodeError>;
}
impl<'a> Alphabet for &'a [u8] {
#[inline(always)]
fn encode(&self, input: &[u8]) -> String {
AsciiEncoder::encode(*self, input)
}
#[inline(always)]
fn decode(&self, input: &str) -> Result<Vec<u8>, DecodeError> {
let mut lookup = [INVALID_INDEX; 256];
for (i, byte) in self.iter().enumerate() {
lookup[*byte as usize] = i as u8;
}
AsciiDecoder::decode(*self, lookup, input)
}
}
impl<'a> Alphabet for &'a str {
#[inline(always)]
fn encode(&self, input: &[u8]) -> String {
if self.is_ascii() {
return self.as_bytes().encode(input);
}
let alphabet: Vec<char> = self.chars().collect();
Utf8Encoder::encode(&alphabet, input)
}
#[inline(always)]
fn decode(&self, input: &str) -> Result<Vec<u8>, DecodeError> {
if self.is_ascii() {
return self.as_bytes().decode(input);
}
let alphabet: Vec<char> = self.chars().collect();
Utf8Decoder::decode(&alphabet, input)
}
}