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Fixed integer overflows. Why did I even write in the first place?

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T-Dark 2021-10-19 17:29:53 +01:00
parent 6f8a49b711
commit 6779d7c898
1 changed files with 21 additions and 6 deletions
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27
ablescript/src/brian.rs
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@ -110,14 +110,14 @@ impl<'a, I: BootlegRead> Interpreter<'a, I> {
let val = self
.get_or_resize_tape_mut()
.ok_or(ProgramError::TapeSizeExceededLimit)?;
*val = val.checked_add(1).ok_or(ProgramError::IntegerOverflow)?;
*val = val.wrapping_add(1)
}
b'-' => {
let val = self
.get_or_resize_tape_mut()
.ok_or(ProgramError::TapeSizeExceededLimit)?;
*val = val.checked_sub(1).ok_or(ProgramError::IntegerUnderflow)?;
*val = val.wrapping_sub(1)
}
b'.' => {
@ -282,8 +282,6 @@ pub enum IoStatus {
/// An error that occurred while the interpreter was advancing
pub enum ProgramError {
DataPointerUnderflow,
IntegerOverflow,
IntegerUnderflow,
InputReadError,
UnmatchedOpeningBracket,
UnmatchedClosingBracket,
@ -297,8 +295,6 @@ impl Display for ProgramError {
"{}",
match self {
ProgramError::DataPointerUnderflow => "data pointer underflow",
ProgramError::IntegerOverflow => "integer overflow",
ProgramError::IntegerUnderflow => "integer underflow",
ProgramError::InputReadError => "input read error",
ProgramError::UnmatchedOpeningBracket => "unmatched `[`",
ProgramError::UnmatchedClosingBracket => "unmatched `]`",
@ -442,4 +438,23 @@ mod tests {
))
);
}
#[test]
fn positive_integer_overflow() {
interpret_with_io(b"+[+]", std::io::empty(), std::io::sink()).unwrap();
}
#[test]
fn negative_integer_overflow() {
interpret_with_io(b"-", std::io::empty(), std::io::sink()).unwrap();
}
#[test]
fn in_the_past_this_used_to_crash_but_not_anymore() {
let mut interpreter = Interpreter::from_ascii(
b"[-]++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++>[-]++>[-]>[-]<<<[>>>+<<<-]>>>[<<[<+>>+<-]>[<+>-]>-]<<<------------>>++++++++++<<[->+>-[>+>>]>[+[-<+>]>+>>]<<<<<<]>>[-]>>>++++++++++<[->-[>+>>]>[+[-<+>]>+>>]<<<<<]>[-]>>[>++++++[-<++++++++>]<.<<+>+>[-]]<[<[->-<]++++++[->++++++++<]>.[-]]<<++++++[-<++++++++>]<.[-]<<[-<+>]<",
std::io::empty()
);
interpreter.interpret_with_output(std::io::sink()).unwrap();
}
}