Lua 5.3 #27

New Issue

open-autonomous-connection · 2019-02-28T21:55:33Z

noncom commented

2019-02-28 21:55:33 +00:00

(Migrated from github.com)

Would be great to let LuaJ support the 5.3 language specification. As I understand, this is the only reliable and living fork of LuaJ as of now and likely for the rest of the future, so that would make much sense.

I think that besides everything else, implementing 5.3 features is especialy beneficial for a tigher intergation with JVM since it introduces support for 32 bit floats, 64 bit ints, and utf-8 strings. All these aspects should help reduce much of the unnecessary casts when interfacing with Java.

At the same time the there seems to be no breaking or overly complex changes required (though I am not too proficient with interpreters and don't really know everything about how LuaJ works).

Sooner or later this should have come up :) LuaJ could not not have this listed in its issues.

Would be great to let LuaJ support the 5.3 language specification. As I understand, this is the only reliable and living fork of LuaJ as of now and likely for the rest of the future, so that would make much sense. I think that besides everything else, implementing 5.3 features is especialy beneficial for a tigher intergation with JVM since it introduces support for 32 bit floats, 64 bit ints, and utf-8 strings. All these aspects should help reduce much of the unnecessary casts when interfacing with Java. At the same time the there seems to be no breaking or overly complex changes required (though I am not too proficient with interpreters and don't really know everything about how LuaJ works). Sooner or later this should have come up :) LuaJ could not not have this listed in its issues.

👍 5

Enyby commented

2019-03-01 04:14:12 +00:00

(Migrated from github.com)

Lua 5.2 binary not compatible with Lua 5.3. So you can not run any binary chunk from 5.2 on 5.3.

noncom commented

2019-03-01 06:57:11 +00:00

(Migrated from github.com)

Backwards-compatibility can be a problem in some cases, but the Lua world does a great deal of effort to minimize this and almost any library works for both Lua versions, so source-wise there should be no problem. I don't think that anyone uses Lua binaries without having the source to recompile them from?

Could it be possible to retain support for 5.2? There are many classes that deal with the bytecode, that would have to be changed for 5.3. But I don't know the extent to which the bytecodes are different. How do you think, is it possible to blend in 5.3, or this would bloat the code and harm performance so that forking is the only solution?

Some time ago I was thinking about implementing this myself, but I could not find any definitive documents on 5.3 bytecode and how is it different from 5.2, and did not yet get to reverse-engineer both C versions.

Backwards-compatibility can be a problem in some cases, but the Lua world does a great deal of effort to minimize this and almost any library works for both Lua versions, so source-wise there should be no problem. I don't think that anyone uses Lua binaries without having the source to recompile them from? Could it be possible to retain support for 5.2? There are many classes that deal with the bytecode, that would have to be changed for 5.3. But I don't know the extent to which the bytecodes are different. How do you think, is it possible to blend in 5.3, or this would bloat the code and harm performance so that forking is the only solution? Some time ago I was thinking about implementing this myself, but I could not find any definitive documents on 5.3 bytecode and how is it different from 5.2, and did not yet get to reverse-engineer both C versions.

Enyby commented

2019-03-01 15:32:24 +00:00

(Migrated from github.com)

I do not know why lua 5.2 not compatible with lua 5.3 in bytecode. It is possible, but lua do not make it.
5.3 need a lot of work.

I do not know why lua 5.2 not compatible with lua 5.3 in bytecode. It is possible, but lua do not make it. 5.3 need a lot of work.

auge commented

2019-10-16 14:08:14 +00:00

(Migrated from github.com)

+1 for 5.3

one of the biggest differences between 5.2 and 5.3 is the removal of the bitwise operations library since 5.3 introduced integer (sub) data types.
what is missing from 5.3 is the native support of various native bitwise operators (i.e. shift left, right, ...) as this is not supported nor recognized in 5.2

Lua 5.3.5  Copyright (C) 1994-2018 Lua.org, PUC-Rio
> a = 4
> print(a << 1)
8

+1 for 5.3 one of the biggest differences between 5.2 and 5.3 is the removal of the bitwise operations library since 5.3 introduced integer (sub) data types. what is missing from 5.3 is the native support of various native bitwise operators (i.e. shift left, right, ...) as this is not supported nor recognized in 5.2 ```lua Lua 5.3.5 Copyright (C) 1994-2018 Lua.org, PUC-Rio > a = 4 > print(a << 1) 8 ```

nirenr commented

2019-10-17 12:49:38 +00:00

(Migrated from github.com)

https://github.com/nirenr/luaj Support for bit operations, support for long integers