Embedding an interpreted language using higher-order functions and types

Using an embedded, interpreted language to control a complicated application can have significant software-engineering benefits. But existing interpreters are designed for embedding into C code. To embed an interpreter into a different language requires an API suited to that language. This paper presents Lua-ML, a new API that is suited to languages that provide higher-order functions and types. The API exploits higher-order functions and types to reduce the amount of glue code needed to use an embedded interpreter. Where embedding in C requires a special-purpose “glue function” for every function to be embedded, embedding in Lua-ML requires only a description of each function's type. Lua-ML also makes it easy to define a Lua function whose behavior depends on the number and types of its arguments.