Handle numbers greater that 10e21 and numbers that start with `0.`followed by more than 5 zeros.

[Ynote]

Description of the issue

As in JavaScript, number output is in fixed notation, except when it is greater that 10e21 and when it starts with 0.followed by more than 5 zeros (cf. http://2ality.com/2012/03/displaying-numbers.html), the cast to a number with parseFloat and the final string equality can only handle the range between 10e21 and 0.00000x cases.

Possible solution

Using a RegExp. In that case, is the usage of parseFloat still appropriate?

[Ynote]

Another case in favor of using a RegExp : isStringANumber('042') doesn't return truebecause of the use ofparseFloat. Should 042returntrue` ?