Module bit32_lib 

bit32 — the Lua 5.2/5.3 32-bit bitwise library.

C source: reference/lua-5.4.7/src/lbitlib.c.

bit32 was introduced in Lua 5.2 and removed in 5.4 once native 64-bit bitwise operators (& | ~ << >>) arrived in 5.3. In a stock build it is present in both 5.2 and 5.3 — 5.3 keeps it under the default-on LUA_COMPAT_BITLIB flag — so init registers it under the V52 | V53 gate. Verified against the reference binaries: type(bit32) is nil / table / table / nil for 5.1 / 5.2 / 5.3 / 5.4. That gate is load-bearing; narrowing it to 5.2-only would drop a 5.3 builtin.

Every operation masks its operands and result to 32 bits (mod 2^32): this unsigned 32-bit window is the library’s defining semantics and is what distinguishes it from 5.3’s native 64-bit operators.

Graduation (idiomatization sprint 2)

The whole 5.2/5.3 surface is implemented and reference-pinned: band bor bxor bnot btest lshift rshift arshift lrotate rrotate extract replace. The behavioral net lives in crates/lua-stdlib/tests/bit32_strengthen.rs (pinned to lua5.2.4, with a lua5.3.6 contrast for the one version-specific behavior — see [arg_u32]).

Functions

open_bit32

Open the bit32 library, leaving the populated table on the stack.