This is Lua 4.0.
* Changes from version 3.2 to 4.0
-------------------------------
Language:
+ new "break" and "for" statements (both numerical and for tables).
+ uniform treatment of globals: globals are now stored in a Lua table.
+ improved error messages.
+ no more '$debug': full speed *and* full debug information.
+ new read form: read(N) for next N bytes.
+ general read patterns now deprecated.
(still available with -DCOMPAT_READPATTERNS.)
+ all return values are passed as arguments for the last function
(old semantics still available with -DLUA_COMPAT_ARGRET)
+ garbage collection tag methods for tables now deprecated.
+ there is now only one tag method for order.
API:
+ New API: fully re-entrant, simpler, and more efficient.
+ New debug API.
Implementation:
+ cleaner virtual machine -- at least 20% faster.
+ non-recursive garbage-collector algorithm.
+ reduced memory usage for programs with many strings.
+ improved treatment for memory allocation errors.
+ improved support for 16-bit machines (we hope).
+ code now compiles unmodified as both ANSI C and C++.
+ numbers in bases other than 10 are converted using strtoul.
+ new -f option in Lua to support #! scripts.
+ luac can now combine text and binaries.
* Changes from version 3.1 to 3.2
-------------------------------
+ redirected all output in Lua's core to _ERRORMESSAGE and _ALERT.
+ increased limit on the number of constants and globals per function
(from 2^16 to 2^24).
+ debugging info (lua_debug and hooks) moved into lua_state and new API
functions provided to get and set this info.
+ new debug lib gives full debugging access within Lua.
+ new table functions "foreachi", "sort", "tinsert", "tremove", "getn".
+ new io functions "flush", "seek".
* Changes from version 3.0 to 3.1
-------------------------------
+ NEW FEATURE: anonymous functions with closures (via "upvalues").
+ new syntax:
- local variables in chunks.
- better scope control with DO block END.
- constructors can now be also written: { record-part; list-part }.
- more general syntax for function calls and lvalues, e.g.:
f(x).y=1
o:f(x,y):g(z)
f"string" is sugar for f("string")
+ strings may now contain arbitrary binary data (e.g., embedded zeros).
+ major code re-organization and clean-up; reduced module interdependecies.
+ no arbitrary limits on the total number of constants and globals.
+ support for multiple global contexts.
+ better syntax error messages.
+ new traversal functions "foreach" and "foreachvar".
+ the default for numbers is now double.
changing it to use floats or longs is easy.
+ complete debug information stored in pre-compiled chunks.
+ sample interpreter now prompts user when run interactively, and also
handles control-C interruptions gracefully.
* Changes from version 2.5 to 3.0
-------------------------------
+ NEW CONCEPT: "tag methods".
Tag methods replace fallbacks as the meta-mechanism for extending the
semantics of Lua. Whereas fallbacks had a global nature, tag methods
work on objects having the same tag (e.g., groups of tables).
Existing code that uses fallbacks should work without change.
+ new, general syntax for constructors {[exp] = exp, ... }.
+ support for handling variable number of arguments in functions (varargs).
+ support for conditional compilation ($if ... $else ... $end).
+ cleaner semantics in API simplifies host code.
+ better support for writing libraries (auxlib.h).
+ better type checking and error messages in the standard library.
+ luac can now also undump.
* Changes from version 2.4 to 2.5
-------------------------------
+ io and string libraries are now based on pattern matching;
the old libraries are still available for compatibility
+ dofile and dostring can now return values (via return statement)
+ better support for 16- and 64-bit machines
+ expanded documentation, with more examples
* Changes from version 2.2 to 2.4
-------------------------------
+ external compiler creates portable binary files that can be loaded faster
+ interface for debugging and profiling
+ new "getglobal" fallback
+ new functions for handling references to Lua objects
+ new functions in standard lib
+ only one copy of each string is stored
+ expanded documentation, with more examples
* Changes from version 2.1 to 2.2
-------------------------------
+ functions now may be declared with any "lvalue" as a name
+ garbage collection of functions
+ support for pipes
* Changes from version 1.1 to 2.1
-------------------------------
+ object-oriented support
+ fallbacks
+ simplified syntax for tables
+ many internal improvements
(end of HISTORY)
