Improve tvf! macro for negative numerical values

[oschijns]

Allow defining the sign of a numerical value without wrapping into into extra parenthesis.
from

  let buffer = tvf!(SimpleStringTvf {
      10 => (-10),
      11 => (-10.25),
      12 => (-2) as Signed,
      13 => (+2.125) as Float,
  });

to

  let buffer = tvf!(SimpleStringTvf {
      10 => -10,
      11 => -10.25,
      12 => -2 as Signed,
      13 => +2.125 as Float,
  });

[reneca]

Some edge cases are not working with this solution. I think you should reconsider the negative sign parsing. It should be apply on the expression.
For me these should work (not the case right now):

let amount: i64 = 7;

let buffer = tvf!(SimpleStringTvf {
    1 => -amount as Signed,
});

assert_eq!(Ok(-7), buffer.get_signed(1));

Also for String conversion:

let buffer = tvf!(SimpleStringTvf {
    1 => -7 as String,
});

assert_eq!(
    Ok("-7"),
    buffer.get_string(1).map(|value| value.to_string()).as_deref(),
);

And maybe an error could be trigger if we try to negate an unsigned value:

let buffer = tvf!(SimpleStringTvf {
    1 => -7 as Unsigned,
    2 => -7u64,
});

assert_ne!(Ok(7), buffer.get_unsigned(1));
assert_ne!(Ok(7), buffer.get_unsigned(2));

[reneca]

You fix common things, but we still have an issue regarding expression.
For example: -(left - right) as Signed, with left = 10 and right = 3, stores 7 instead of -7. Can you also consider it please ?

Also what can we do about these ?

-7 as Unsigned // stores 7
-7u64          // stores 7
-7 as Byte     // stores 7

BTW you didn't sign your last commit.
And can you increase prose_macros version to 0.5.1 please.

[reneca]

User can also put !false and it'll be consider as false. It should consume the token only if it's -.

[oschijns]

Also what can we do about these ?

-7 as Unsigned // stores 7
-7u64          // stores 7
-7 as Byte     // stores 7

They should throw an error. I'll look into it.

[oschijns]

I think I've fixed some of the issues. But I am not satisfied with the implementation.
value.rs and literal.rs are kind of doing the same thing so there should be a way to group them.