treat variable/constant/specific symbols as strings

[ttibensky]

There are symbols with leading zeros, e.g. 0308 https://www.mbank.sk/pomoc/info/ucty/zoznam-najpouzivanejsich-konstantnych-symbolov.html. If you treat it as an integer, the first zero will be ommited resulting in an incorrect symbol 308.

[ttibensky]

Here is a change proposal #31. You would also need to modify the documentation and perhaps do a new major release since this is a breaking change.

[RikudouSage]

Released as 4.0.0