My Joy Engine

cpcogan — 2007-01-07 21:50:41

My Joy engine is an "object" that allows the calling code to use Joy

as an internal macro or scripting language. Each instance is

independent of any others, so different dictionaries can be used for

each, and one instance can be used as a macro language for a Joy IDE,

so the IDE itself can be extended by the programmer, while the code

being developed is executed in another instance of the engine. This is

analogous to using C as a macro language in an IDE for developing

programs in C.



I have two source-code interfaces for the Joy engine itself (that is,

means of passing source to the Joy engine). One takes ordinary source

code, with directives, comments and such, and processes it, compiling

code or executing directives as it goes. The other assumes that there

are no comments, no directives, nothing to confuse a simple interface.

It won't even do includes. This is intended for quick

expression-handling, not passing Joy a whole application. 



Of course, the calling code can also access the dictionary and other

parts of the engine, because virtually all of it is public. This means

that an application can basically manipulate everything that the

engine's own code uses, so a calling application can clean out unused

functions from the dictionary, or set various flags and so on. As I

get more experience, I will probably write property-wrappers for the

variables, so that the engine is protected against invalid values

being given to its internal variables, but, for now, my current

interfacing seems adequate.