js_int
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.
* In the upcoming ECMAScript 2020, JavaScript will probably gain support
for integers. There is a proposal for a BigInt type type that is not
far from becoming part of the JavaScript specification. It won't make this crate
obsolete in any way though, since there will still be lots of JS code using
Number, and code in other languages that assumes its use.
This crate requires rustc >= 1.35.
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
float_deserialize feature. This will still not deserialize numbers with a
non-zero fractional component. Enabling the lax_deserialize feature will discard the
fractional part instead of declining to deserialize. 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.