1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
//! Executor engine implementation for Brainfuck interpreter.
//!
//! This predominantly allows implementation of a [`u16`] executor.
use std::io::Read;
use num_traits::{One, Unsigned, WrappingAdd, WrappingSub, Zero};
use crate::executor::{self, Error};
/// Generic engine implementation for the Brainfuck interpreter.
pub trait Engine {
/// Inner type of the Tape.
type TapeInner: Clone + Copy + Unsigned + WrappingAdd + WrappingSub + One + Zero;
/// Read one byte from stdin.
///
/// # Errors
///
/// This function will return an error if it is unable to read from stdin,
/// or if it indexes out of bounds.
fn read_byte() -> Result<Self::TapeInner, Error>;
/// Write the provided byte to stdout.
///
/// # Errors
///
/// This function will return an error if it is unable to write a byte to
/// stdout.
fn write_byte(byte: Self::TapeInner) -> Result<(), Error>;
}
impl Engine for executor::U8 {
type TapeInner = u8;
fn read_byte() -> Result<u8, Error> {
let mut input: [u8; 1] = [0; 1];
std::io::stdin().read_exact(&mut input)?;
Ok(input[0])
}
fn write_byte(byte: u8) -> Result<(), Error> {
print!("{}", char::from(byte));
Ok(())
}
}
impl Engine for executor::U16 {
type TapeInner = u16;
fn read_byte() -> Result<u16, Error> {
let mut input: [u8; 2] = [0; 2];
std::io::stdin().read_exact(&mut input)?;
let number = ((u16::from(input[0])) << 8i32) | u16::from(input[1]);
Ok(number)
}
fn write_byte(byte: u16) -> Result<(), Error> {
print!("{}", String::from_utf16_lossy(&[byte]));
Ok(())
}
}
|