Implement dostring() function in box.lua.

mod/box/box.lua

@@ -16,6 +16,14 @@ function box.select_limit(space, index, offset, limit, ...)
                                  ...))
 end
 
+function box.dostring(s, ...)
+    local chunk, message = loadstring(s)
+    if chunk == nil then
+        error(message, 2)
+    end
+    return chunk(...)
+end
+
 --
 --
 --

test/box/lua.test

@@ -526,3 +526,11 @@ exec admin "lua box.counter.dec(0, 1)"
 exec admin "lua box.select(0, 0, 1)"
 exec admin "lua box.counter.dec(0, 1)"
 exec admin "lua box.select(0, 0, 1)"
+
+
+print """# box.dostring()"""
+exec admin "lua box.dostring('abc')"
+exec admin "lua box.dostring('abc=2')"
+exec admin "lua box.dostring('return abc')"
+exec admin "lua box.dostring('return ...', 1, 2, 3)"
+