AbleScript/ablescript
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Merge pull request #43 from T-Dark0/T-Dark_fix_brainfuck_overflows

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Fixed integer overflows. Why did I even write `checked_add` in the first place?
This commit is contained in:
Erin 2021-10-19 23:37:47 +02:00 committed by GitHub
parent 6f8a49b711 3e8b80af2a
commit 0f198a2554
1 changed files with 12 additions and 6 deletions
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18
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 +438,14 @@ 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();
}
}