Incompatibilities with Previous Versions

• The whole tag-method scheme was replaced by metatables.

• Function calls written between parentheses result in exactly one value.

• The precedence of or is smaller than the precedence of and.

• in, false, and true are reserved words.

• When a literal string of the form [[...]] starts with a newline, this newline is ignored.

• Upvalues in the form %var are obsolete; use external local variables instead.

• Most library functions now are defined inside tables. There is a compatibility script (compat.lua) that redefines most of them as global names.

• The call function is deprecated. Use f(unpack(tab)) instead of call(f, tab) for unprotected calls, or the new pcall function for protected calls.

• dostring is deprecated. Use instead.

• The read option *w is obsolete.

• The format option %n$ is obsolete.

• lua_open does not have a stack size as its argument (stacks are dynamic).