Does it has BigDecimal in mruby?

[torsakch]

I found that in some circumstances I need highly precise decimal type for calculation. So does Mruby support BigDecimal or does it has Mruby gems to support that? thanks!! If not, what should I do the achieve that?

[Asmod4n]

There is a gem to add bignum support.
https://github.com/chasonr/mruby-gmp-bignum/ or https://github.com/chasonr/mruby-bignum/
Read the readme on how to use it, because it either needs a forked mruby version or you have to use special functions to do math on them.

[torsakch]

@Asmod4n Thank you very much. However, as my understandings, the gem does not support the BigDecimal. For example, if I want "123456789.123456789 + 123456789.123456789", it should be "246913578.246913578". But for now I got "246913578.246913". Am I correct?

[Asmod4n]

if you want to use + - * / you have to read the readme of the gem.
It should work with 123456789.123456789.to_bn + 123456789.123456789 but i haven't use those gems yet.

[beoran]

Since there are external mrbgems to implement bignum, and the ISO standard does not require bignum, I suggest we close this issue as wontfix.

[chasonr]

Just to clarify: the Bignum gems implement integer arithmetic, not decimal floating point as torsakch seems to want. They could be used as a basis for a BigDecimal class, but they do not provide BigDecimal themselves.