Converts a string to a BigFloat.
BigFloat.parseFloat(string)
string
A string that contains a floating-point number.
The parsed BigFloat.
If the string can’t be parsed as a floating-point number, returns BigFloat with NaN value.
BigFloat.parseFloat("1.234")
1.234
BigFloat.parseFloat("1e10")
10000000000
BigFloat.isNaN(parseFloat("oops"))
true