compat.lua
---------------- --- Lua 5.1/5.2 compatibility -- Ensures that table.pack and package.searchpath are available -- for Lua 5.1 and LuaJIT. -- The exported function load is Lua 5.2 compatible. -- compat.setfenv andcompat.getfenvare available for Lua 5.2, although -- they are not always guaranteed to work. -- @module pl.compat local compat = {} compat.lua51 = _VERSION == 'Lua 5.1' --- execute a shell command. -- This is a compatibility function that returns the same for Lua 5.1 and Lua 5.2 -- @param cmd a shell command -- @return true if successful -- @return actual return code function compat.execute (cmd) local res1,res2,res2 = os.execute(cmd) if compat.lua51 then return res1==0,res1 else return not not res1,res2 end end ---------------- -- Load Lua code as a text or binary chunk. -- @param ld code string or loader -- @param[opt] source name of chunk for errors -- @param[opt] mode 'b', 't' or 'bt' -- @param[opt] env environment to load the chunk in -- @function compat.load --------------- -- Get environment of a function. -- With Lua 5.2, may return nil for a function with no global references! -- Based on code by [Sergey Rozhenko](http://lua-users.org/lists/lua-l/2010-06/msg00313.html) -- @param f a function or a call stack reference -- @function compat.setfenv --------------- -- Set environment of a function -- @param f a function or a call stack reference -- @param env a table that becomes the new environment off-- @function compat.setfenv if compat.lua51 then -- define Lua 5.2 style load() if not tostring(assert):match 'builtin' then -- but LuaJIT's load _is_ compatible local lua51_load = load function compat.load(str,src,mode,env) local chunk,err if type(str) == 'string' then if str:byte(1) == 27 and not (mode or 'bt'):find 'b' then return nil,"attempt to load a binary chunk" end chunk,err = loadstring(str,src) else chunk,err = lua51_load(str,src) end if chunk and env then setfenv(chunk,env) end return chunk,err end else compat.load = load end compat.setfenv, compat.getfenv = setfenv, getfenv else compat.load = load -- setfenv/getfenv replacements for Lua 5.2 -- by Sergey Rozhenko -- http://lua-users.org/lists/lua-l/2010-06/msg00313.html -- Roberto Ierusalimschy notes that it is possible for getfenv to return nil -- in the case of a function with no globals: -- http://lua-users.org/lists/lua-l/2010-06/msg00315.html function compat.setfenv(f, t) f = (type(f) == 'function' and f or debug.getinfo(f + 1, 'f').func) local name local up = 0 repeat up = up + 1 name = debug.getupvalue(f, up) until name == '_ENV' or name == nil if name then debug.upvaluejoin(f, up, function() return name end, 1) -- use unique upvalue debug.setupvalue(f, up, t) end if f ~= 0 then return f end end function compat.getfenv(f) local f = f or 0 f = (type(f) == 'function' and f or debug.getinfo(f + 1, 'f').func) local name, val local up = 0 repeat up = up + 1 name, val = debug.getupvalue(f, up) until name == '_ENV' or name == nil return val end end --- Lua 5.2 Functions Available for 5.1 -- @section lua52 --- pack an argument list into a table. -- @param ... any arguments -- @return a table with field n set to the length -- @return the length -- @function table.pack if not table.pack then function table.pack (...) return {n=select('#',...); ...} end end ------ -- return the full path where a Lua module name would be matched. -- @param mod module name, possibly dotted -- @param path a path in the same form as package.path or package.cpath -- @see path.package_path -- @function package.searchpath if not package.searchpath then local sep = package.config:sub(1,1) function package.searchpath (mod,path) mod = mod:gsub('%.',sep) for m in path:gmatch('[^;]+') do local nm = m:gsub('?',mod) local f = io.open(nm,'r') if f then f:close(); return nm end end end end return compat