dsl

Yes. That's right. I want to be able to paste an expression like: "a && b || c" directly into source code as a string: const std::string expression_text("a && b || c"); Create a lazily evaluated structure with it: Expr expr(magical_function(expression_text)); then later on evaluate substituting in known values: evaluate(expr, a, b, c); I'd want to expand this little DSL later so does something a little more complicated using some non-C++ syntax so I can't simply hardcode my expression the simple way. The use case is that I'll be able to copy and paste the same logic from another module used in

In Kotlin, I want to add extension methods to a class, for example to class Entity . But I only want to see these extensions when Entity is within a transaction, otherwise hidden. For example, if I define these classes and extensions: interface Entity {} fun Entity.save() {} fun Entity.delete() {} class Transaction { fun start() {} fun commit() {} fun rollback() {} } I now can accidentally call save() and delete() at any time, but I only want them available after the start() of a transaction and no longer after commit() or rollback() ? Currently I can do this, which is wrong: someEntity.save()

I'm after creating a simple mini-language parser in Python, programming close to the problem domain and all that. Anyway, I was wondering how the people on here would go around doing that - what are the preferred ways of doing this kind of thing in Python? I'm not going to give specific details of what I'm after because at the moment I'm just investigating how easy this whole field is in Python. Thanks for your input! Pyparsing is handy for writing "little languages". I gave a presentation at PyCon'06 on writing a simple adventure game engine, in which the language being parsed and interpreted

This question already has an answer here: Javascript: operator overloading 4 answers Overloading Arithmetic Operators in JavaScript? 11 answers Is it possible to define custom operators between instances of a type in JavaScript? For example, given that I have a custom vector class, is it possible to use vect1 == vect2 to check for equality, whilst the underlying code would be something like this? operator ==(a, b) { return a.x == b.x && a.y == b.y && a.z == b.z; } (This is nonsense of course.) I agree that the equal function on the vector prototype is the best solution. Note that you can also