crain 0.1.0

A Brainfuck compiler/interpreter/tool
Documentation 
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use super::*;

/// 8-bits Cell. It is essentially a wrapper around u8.
pub type Cell8 = u8;

/// 16-bits Cell. It is essentially a wrapper around u16.
pub type Cell16 = u16;

/// 32-bits Cell. It is essentially a wrapper around u32.
pub type Cell32 = u32;

/// 64-bits Cell. It is essentially a wrapper around u64.
pub type Cell64 = u64;

/// 128-bits Cell. It is essentially a wrapper around u128.
pub type Cell128 = u128;

macro_rules! impl_bfcell {
    ($t:ty) => {
        impl BfCell for $t {
            const ZERO: Self = 0;
            const ONE: Self = 1;

            fn add(&mut self, rhs: Self) {
                *self = self.wrapping_add(rhs);
            }
            fn sub(&mut self, rhs: Self) {
                *self = self.wrapping_sub(rhs);
            }

            fn iszero(self) -> bool {
                self == 0
            }

            fn input(&mut self, bfinput: &mut impl std::io::Read) -> Result<(), std::io::Error> {
                // compiler cannot know it
                const BYTES_COUNT: usize = (<$t>::BITS / 8) as usize;
                let mut buf = [0u8; BYTES_COUNT];

                bfinput.read_exact(&mut buf).or_else(|e| {
                    if e.kind() == std::io::ErrorKind::UnexpectedEof {
                        *self = <$t>::ZERO;
                        Ok(())
                    } else {
                        Err(e)
                    }
                })?;

                *self = <$t>::from_ne_bytes(buf);

                Ok(())
            }

            fn output(self, bfoutput: &mut impl std::io::Write) -> Result<(), std::io::Error> {
                let buf = self.to_ne_bytes();

                bfoutput.write_all(&buf)?;
                bfoutput.flush()?;

                Ok(())
            }
        }
    };
}

impl_bfcell!(Cell8);
impl_bfcell!(Cell16);
impl_bfcell!(Cell32);
impl_bfcell!(Cell64);
impl_bfcell!(Cell128);