## Summary
Often, when fixing, we need to dedent a block of code (e.g., if we
remove an `if` and dedent its body). Today, we use LibCST to parse and
adjust the indentation, which is really expensive -- but this is only
really necessary if the block contains a multiline string, since naively
adjusting the indentation for such a string can change the whitespace
_within_ the string.
This PR uses a simple dedent implementation for cases in which the block
doesn't intersect with a multi-line string (or an f-string, since we
don't support tracking multi-line strings for f-strings right now).
We could improve this even further by using the ranges to guide the
dedent function, such that we don't apply the dedent if the line starts
within a multiline string. But that would also need to take f-strings
into account, which is a little tricky.
## Test Plan
`cargo test`
## Summary
This is a follow-up to #7469 that attempts to achieve similar gains, but
without introducing malachite. Instead, this PR removes the `BigInt`
type altogether, instead opting for a simple enum that allows us to
store small integers directly and only allocate for values greater than
`i64`:
```rust
/// A Python integer literal. Represents both small (fits in an `i64`) and large integers.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct Int(Number);
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Number {
/// A "small" number that can be represented as an `i64`.
Small(i64),
/// A "large" number that cannot be represented as an `i64`.
Big(Box<str>),
}
impl std::fmt::Display for Number {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Number::Small(value) => write!(f, "{value}"),
Number::Big(value) => write!(f, "{value}"),
}
}
}
```
We typically don't care about numbers greater than `isize` -- our only
uses are comparisons against small constants (like `1`, `2`, `3`, etc.),
so there's no real loss of information, except in one or two rules where
we're now a little more conservative (with the worst-case being that we
don't flag, e.g., an `itertools.pairwise` that uses an extremely large
value for the slice start constant). For simplicity, a few diagnostics
now show a dedicated message when they see integers that are out of the
supported range (e.g., `outdated-version-block`).
An additional benefit here is that we get to remove a few dependencies,
especially `num-bigint`.
## Test Plan
`cargo test`
