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1 HISTORY for Lua 5.1
3 * Changes from version 5.0 to 5.1
4 -------------------------------
5 Language:
6 + new module system.
7 + new semantics for control variables of fors.
8 + new semantics for setn/getn.
9 + new syntax/semantics for varargs.
10 + new long strings and comments.
11 + new `mod' operator (`%')
12 + new length operator #t
13 + metatables for all types
14 API:
15 + new functions: lua_createtable, lua_get(set)field, lua_push(to)integer.
16 + user supplies memory allocator (lua_open becomes lua_newstate).
17 + luaopen_* functions must be called through Lua.
18 Implementation:
19 + new configuration scheme via luaconf.h.
20 + incremental garbage collection.
21 + better handling of end-of-line in the lexer.
22 + fully reentrant parser (new Lua function `load')
23 + better support for 64-bit machines.
24 + native loadlib support for Mac OS X.
25 + standard distribution in only one library (lualib.a merged into lua.a)
27 * Changes from version 4.0 to 5.0
28 -------------------------------
29 Language:
30 + lexical scoping.
31 + Lua coroutines.
32 + standard libraries now packaged in tables.
33 + tags replaced by metatables and tag methods replaced by metamethods,
34 stored in metatables.
35 + proper tail calls.
36 + each function can have its own global table, which can be shared.
37 + new __newindex metamethod, called when we insert a new key into a table.
38 + new block comments: --[[ ... ]].
39 + new generic for.
40 + new weak tables.
41 + new boolean type.
42 + new syntax "local function".
43 + (f()) returns the first value returned by f.
44 + {f()} fills a table with all values returned by f.
45 + \n ignored in [[\n .
46 + fixed and-or priorities.
47 + more general syntax for function definition (e.g. function a.x.y:f()...end).
48 + more general syntax for function calls (e.g. (print or write)(9)).
49 + new functions (time/date, tmpfile, unpack, require, load*, etc.).
50 API:
51 + chunks are loaded by using lua_load; new luaL_loadfile and luaL_loadbuffer.
52 + introduced lightweight userdata, a simple "void*" without a metatable.
53 + new error handling protocol: the core no longer prints error messages;
54 all errors are reported to the caller on the stack.
55 + new lua_atpanic for host cleanup.
56 + new, signal-safe, hook scheme.
57 Implementation:
58 + new license: MIT.
59 + new, faster, register-based virtual machine.
60 + support for external multithreading and coroutines.
61 + new and consistent error message format.
62 + the core no longer needs "stdio.h" for anything (except for a single
63 use of sprintf to convert numbers to strings).
64 + lua.c now runs the environment variable LUA_INIT, if present. It can
65 be "@filename", to run a file, or the chunk itself.
66 + support for user extensions in lua.c.
67 sample implementation given for command line editing.
68 + new dynamic loading library, active by default on several platforms.
69 + safe garbage-collector metamethods.
70 + precompiled bytecodes checked for integrity (secure binary dostring).
71 + strings are fully aligned.
72 + position capture in string.find.
73 + read('*l') can read lines with embedded zeros.
75 * Changes from version 3.2 to 4.0
76 -------------------------------
77 Language:
78 + new "break" and "for" statements (both numerical and for tables).
79 + uniform treatment of globals: globals are now stored in a Lua table.
80 + improved error messages.
81 + no more '$debug': full speed *and* full debug information.
82 + new read form: read(N) for next N bytes.
83 + general read patterns now deprecated.
84 (still available with -DCOMPAT_READPATTERNS.)
85 + all return values are passed as arguments for the last function
86 (old semantics still available with -DLUA_COMPAT_ARGRET)
87 + garbage collection tag methods for tables now deprecated.
88 + there is now only one tag method for order.
89 API:
90 + New API: fully re-entrant, simpler, and more efficient.
91 + New debug API.
92 Implementation:
93 + faster than ever: cleaner virtual machine and new hashing algorithm.
94 + non-recursive garbage-collector algorithm.
95 + reduced memory usage for programs with many strings.
96 + improved treatment for memory allocation errors.
97 + improved support for 16-bit machines (we hope).
98 + code now compiles unmodified as both ANSI C and C++.
99 + numbers in bases other than 10 are converted using strtoul.
100 + new -f option in Lua to support #! scripts.
101 + luac can now combine text and binaries.
103 * Changes from version 3.1 to 3.2
104 -------------------------------
105 + redirected all output in Lua's core to _ERRORMESSAGE and _ALERT.
106 + increased limit on the number of constants and globals per function
107 (from 2^16 to 2^24).
108 + debugging info (lua_debug and hooks) moved into lua_state and new API
109 functions provided to get and set this info.
110 + new debug lib gives full debugging access within Lua.
111 + new table functions "foreachi", "sort", "tinsert", "tremove", "getn".
112 + new io functions "flush", "seek".
114 * Changes from version 3.0 to 3.1
115 -------------------------------
116 + NEW FEATURE: anonymous functions with closures (via "upvalues").
117 + new syntax:
118 - local variables in chunks.
119 - better scope control with DO block END.
120 - constructors can now be also written: { record-part; list-part }.
121 - more general syntax for function calls and lvalues, e.g.:
122 f(x).y=1
123 o:f(x,y):g(z)
124 f"string" is sugar for f("string")
125 + strings may now contain arbitrary binary data (e.g., embedded zeros).
126 + major code re-organization and clean-up; reduced module interdependecies.
127 + no arbitrary limits on the total number of constants and globals.
128 + support for multiple global contexts.
129 + better syntax error messages.
130 + new traversal functions "foreach" and "foreachvar".
131 + the default for numbers is now double.
132 changing it to use floats or longs is easy.
133 + complete debug information stored in pre-compiled chunks.
134 + sample interpreter now prompts user when run interactively, and also
135 handles control-C interruptions gracefully.
137 * Changes from version 2.5 to 3.0
138 -------------------------------
139 + NEW CONCEPT: "tag methods".
140 Tag methods replace fallbacks as the meta-mechanism for extending the
141 semantics of Lua. Whereas fallbacks had a global nature, tag methods
142 work on objects having the same tag (e.g., groups of tables).
143 Existing code that uses fallbacks should work without change.
144 + new, general syntax for constructors {[exp] = exp, ... }.
145 + support for handling variable number of arguments in functions (varargs).
146 + support for conditional compilation ($if ... $else ... $end).
147 + cleaner semantics in API simplifies host code.
148 + better support for writing libraries (auxlib.h).
149 + better type checking and error messages in the standard library.
150 + luac can now also undump.
152 * Changes from version 2.4 to 2.5
153 -------------------------------
154 + io and string libraries are now based on pattern matching;
155 the old libraries are still available for compatibility
156 + dofile and dostring can now return values (via return statement)
157 + better support for 16- and 64-bit machines
158 + expanded documentation, with more examples
160 * Changes from version 2.2 to 2.4
161 -------------------------------
162 + external compiler creates portable binary files that can be loaded faster
163 + interface for debugging and profiling
164 + new "getglobal" fallback
165 + new functions for handling references to Lua objects
166 + new functions in standard lib
167 + only one copy of each string is stored
168 + expanded documentation, with more examples
170 * Changes from version 2.1 to 2.2
171 -------------------------------
172 + functions now may be declared with any "lvalue" as a name
173 + garbage collection of functions
174 + support for pipes
176 * Changes from version 1.1 to 2.1
177 -------------------------------
178 + object-oriented support
179 + fallbacks
180 + simplified syntax for tables
181 + many internal improvements
183 (end of HISTORY)