Crate js_int provides JavaScript-interoperable integer types.
JavaScript does not have native integers. Instead it represents all numeric
values with a single Number type which is represented as an
IEEE 754 floating-point value.*
Rust's i64 and u64 types can contain values outside the range of what can be
represented in a JavaScript Number.
This crate provides the types Int and UInt which wrap i64 and u64,
respectively. These types add bounds checking to ensure the contained value is
within the range representable by a JavaScript Number. They provide useful
trait implementations to easily convert from Rust's primitive integer types.
* Since the creation of this crate, JavaScript has gained support for
larger integers in the form of the BigInt type.
It doesn't make this crate obsolete in any way though, since there is still
lots of code that operates on JS Numbers or puts the same bounds on integers
as the types from this crate do.
This crate requires rustc >= 1.46.
This crate is no_std-compatible with default-features = false. This will
disable the std feature, which at the time of writing will only omit the
implementations of std::error::Error for ParseIntError and
TryFromIntError.
(De-)Serialization via serde is supported via the serde feature, even
without the std feature.
Deserialization can be routed through f64 instead of u64 with the
(U)Int::deserialize_via_float methods. This will still not deserialize numbers with a
non-zero fractional component. Please be aware that
serde_json doesn't losslessly parse large floats with a fractional part by
default (even if the fractional part is .0). To fix that, enable its
float_roundtrip feature.