Tutorial by Topics: lua

Lua is minimalistic, lightweight and embeddable scripting language. It's being designed, implemented, and maintained by a team at PUC-Rio, the Pontifical Catholic University of Rio de Janeiro in Brazil. The mailing list is open to get involved. Common use-cases for Lua includes scripting video...

lua_State *L = lua_open(); // Create a new VM state; Lua 5.0 lua_State *L = luaL_newstate(); // Create a new VM state; Lua 5.1+ int luaL_dofile(lua_State *L, const char *filename); // Run a lua script with the given filename using the specified lua_State void luaL_openlibs(lua_State *L); // Lo...

Booleans, truth, and falsity are straightforward in Lua. To review: There is a boolean type with exactly two values: true and false. In a conditional context (if, elseif, while, until), a boolean is not required. Any expression can be used. In a conditional context, false and nil count as fal...

XPath expressions are used to navigate and select one or more nodes within an XML tree document, such as selecting a certain element or attribute node. See this W3C recommendation for a reference on this language.

CTFE is a mechanism which allows the compiler to execute functions at compile time. There is no special set of the D language necessary to use this feature - whenever a function just depends on compile time known values the D compiler might decide to interpret it during compilation. You can also ...

eval "source" eval "source", binding eval "source", proc binding.eval "source" # equal to eval "source", binding ParameterDetails"source"Any Ruby source codebindingAn instance of Binding classprocAn instance of Proc class

For more detail, see Property and Item Evaluation Order on the MSDN documentation page Comparing Properties and Items.

This is supposed to explain the evaluation order as unambiguously as possible. It is probably less ideally suited as an introduction to Mathematica execution. It builds on Mathematica's tutorial/Evaluation page by explaining the order in which different rules are applied and explaining which funct...

In JavaScript, the eval function evaluates a string as if it were JavaScript code. The return value is the result of the evaluated string, e.g. eval('2 + 2') returns 4. eval is available in the global scope. The lexical scope of the evaluation is the local scope unless invoked indirectly (e.g. var ...

The EVALUATE statement is a multiple branch, multiple join, conditional test and selection structure.

Redis provides a couple of mechanisms for extending the functionality of the database. One mechanism is through the use of server-side LUA scripts that can be executed to manipulate data. Lua scripts can be useful to perform expensive operations or to implement atomic operations that require logic...

Dplyr and many modern libraries in R use non-standard evaluation (NSE) for interactive programming and standard evaluation (SE) for programming1. For instance, the summarise() function use non-standard evaluation but relies on the summarise_() which uses standard evaluation. The lazyeval library m...