moonscript, busted, penlight packages + debugger speed improvements

pl/apis/compat.lua

@@ -0,0 +1,188 @@
+----------------
+--- Lua 5.1/5.2/5.3 compatibility.
+-- Injects `table.pack`, `table.unpack`, and `package.searchpath` in the global
+-- environment, to make sure they are available for Lua 5.1 and LuaJIT.
+--
+-- All other functions are exported as usual in the returned module table.
+--
+-- NOTE: everything in this module is also available in `pl.utils`.
+-- @module pl.compat
+local compat = {}
+
+--- boolean flag this is Lua 5.1 (or LuaJIT).
+-- @field lua51
+compat.lua51 = _VERSION == 'Lua 5.1'
+
+--- boolean flag this is LuaJIT.
+-- @field jit
+compat.jit = (tostring(assert):match('builtin') ~= nil)
+
+--- boolean flag this is LuaJIT with 5.2 compatibility compiled in.
+-- @field jit52
+if compat.jit then
+    -- 'goto' is a keyword when 52 compatibility is enabled in LuaJit
+    compat.jit52 = not loadstring("local goto = 1")
+end
+
+--- the directory separator character for the current platform.
+-- @field dir_separator
+compat.dir_separator = _ENV.package.config:sub(1,1)
+
+--- boolean flag this is a Windows platform.
+-- @field is_windows
+compat.is_windows = compat.dir_separator == '\\'
+
+--- execute a shell command, in a compatible and platform independent way.
+-- This is a compatibility function that returns the same for Lua 5.1 and
+-- Lua 5.2+.
+--
+-- NOTE: Windows systems can use signed 32bit integer exitcodes. Posix systems
+-- only use exitcodes 0-255, anything else is undefined.
+-- @param cmd a shell command
+-- @return true if successful
+-- @return actual return code
+function compat.execute(cmd)
+    local res1,res2,res3 = os.execute(cmd)
+    if res2 == "No error" and res3 == 0 and compat.is_windows then
+      -- os.execute bug in Lua 5.2+ not reporting -1 properly on Windows
+      res3 = -1
+    end
+    if compat.lua51 and not compat.jit52 then
+        if compat.is_windows then
+            return res1==0,res1
+        else
+            res1 = res1 > 255 and res1 / 256 or res1
+            return res1==0,res1
+        end
+    else
+        if compat.is_windows then
+            return res3==0,res3
+        else
+            return not not res1,res3
+        end
+    end
+end
+
+----------------
+-- Load Lua code as a text or binary chunk (in a Lua 5.2 compatible way).
+-- @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 (in a Lua 5.1 compatible way).
+-- Not 100% compatible, so with Lua 5.2 it 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.getfenv
+
+---------------
+-- Set environment of a function (in a Lua 5.1 compatible way).
+-- @param f a function or a call stack reference
+-- @param env a table that becomes the new environment of `f`
+-- @function compat.setfenv
+
+if compat.lua51 then -- define Lua 5.2 style load()
+    if not compat.jit 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
+
+--- Global exported functions (for Lua 5.1 & LuaJIT)
+-- @section lua52
+
+--- pack an argument list into a table.
+-- @param ... any arguments
+-- @return a table with field n set to the length
+-- @function table.pack
+if not table.pack then
+    function table.pack (...)       -- luacheck: ignore
+        return {n=select('#',...); ...}
+    end
+end
+
+--- unpack a table and return the elements.
+--
+-- NOTE: this version does NOT honor the n field, and hence it is not nil-safe.
+-- See `utils.unpack` for a version that is nil-safe.
+-- @param t table to unpack
+-- @param[opt] i index from which to start unpacking, defaults to 1
+-- @param[opt] t index of the last element to unpack, defaults to #t
+-- @return multiple return values from the table
+-- @function table.unpack
+-- @see utils.unpack
+if not table.unpack then
+    table.unpack = unpack           -- luacheck: ignore
+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)    -- luacheck: ignore
+        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