5.4.6

Lua 5.4 was released on 29 Jun 2020. Its main new features are a new generational mode for garbage collection and const and to-be-closed variables.

Here are the main changes introduced in Lua 5.4. The reference manual lists the incompatibilities that had to be introduced.

Main changes…

• new generational mode for garbage collection
• to-be-closed variables
• const variables
• userdata can have multiple user values
• new implementation for math.random
• warning system
• debug information about function arguments and returns
• new semantics for the integer 'for' loop
• optional 'init' argument to 'string.gmatch'
• new functions 'lua_resetthread' and 'coroutine.close'
• string-to-number coercions moved to the string library
• allocation function allowed to fail when shrinking a memory block
• new format '%p' in 'string.format'
• utf8 library accepts codepoints up to 2^31