(liii bitwise) and (srfi srfi-151)

[da-liii]

https://srfi.schemers.org/srfi-151/srfi-151.html

We need to create two new library to add bitwise support.

There are already logand, logor available in S7 Scheme, and adding srfi-151 support could make Goldfish Scheme more portable!

• [x] and, ior: https://github.com/LiiiLabs/goldfish/issues/85
• [x] not: https://github.com/LiiiLabs/goldfish/issues/86
• [x] xor: https://github.com/LiiiLabs/goldfish/issues/87
• [ ] eqv
• [x] nand, nor
• [x] andc1, andc2
• [x] orc1, orc2
• [x] arithmetic-shift: https://github.com/LiiiLabs/goldfish/issues/93
• [x] bit-count
• [ ] integer-length
• [ ] bitwise-if
• ...

[JackYansongLi]

I've made a pull request which implemented bitwise-or and bitwise-and. A new library srfi-151 was added in Section 2.8 which is automatically imported by (liii base).

[da-liii]

I suggest we should keep the srfi-151 related code in (liii bitwise). That's my initial design. Bitwise operations are not defined in R7RS. We should not keep it in (liii base)

[da-liii]

(srfi srfi-151) is the impl, and (liii bitwise) is the interface

[da-liii]

The reason why SRFI-2 and SRFI-8 is exported in (liii base) is that there is only 1 routine in SRFI 2 and SRFI-8.

But for SRFI-151, there are many routines to be implemented. That's why it should be organized in (liii bitwise).

[JackYansongLi]

I've made a new pull request.

[da-liii]

Bit Twiddling Hacks

https://graphics.stanford.edu/~seander/bithacks.html