Update Lexical Version

[Alexhuszagh]

Hi, and thanks for all the hard work on Nom.

Prerequisites

Nom uses a dependency I maintain, lexical-core, which used to define a C-API and Rust API within a single crate. Due to symbol issues and to remove unnecessary functionality from lexical-core, the C-API was separated into a new crate. Other bug fixes have since been implemented, for example, in ensuring full standard compliance in parsing weird edge-cases like ". ", among others.

Issues

Other uses have reported issues with older versions of lexical:

Undefined Symbols when building on Windows
Symbol Issues when used in a proc macro
Undefined Symbols when building on Windows
Incorrect result with parsing ". "

Versions

To support Rustc versions 1.31+, as Nom currently does, please use lexical-core = "0.6" in Cargo.toml, which supports any version of Rustc >= 1.24.0.

F64 Complete

The patch for the complete, f64 parser would be:

#[cfg(feature = "lexical")]
pub fn double<T, E:ParseError<T>>(input: T) -> IResult<T, f64, E>
where
  T: crate::traits::AsBytes + InputLength + Slice<RangeFrom<usize>>,
{
  match ::lexical_core::parse_partial(input.as_bytes()) {
    Ok((value, processed)) => Ok((input.slice(processed..), value)),
    Err(_) => Err(Err::Error(E::from_error_kind(input, ErrorKind::Float)))
  }
}

F64 Streaming

The patch for the streaming, f64 parser would be:

#[cfg(feature = "lexical")]
pub fn double<T, E:ParseError<T>>(input: T) -> IResult<T, f64, E>
where
  T: crate::traits::AsBytes + InputLength + Slice<RangeFrom<usize>>,
{
  match ::lexical_core::parse_partial(input.as_bytes()) {
    Ok((value, processed)) => {
      if (processed == input.input_len()) {
        Err(Err::Incomplete(Needed::Unknown))
      } else {
        Ok((input.slice(processed..), value))
      }
    },
    Err(_) => Err(Err::Error(E::from_error_kind(input, ErrorKind::Float)))
  }
}