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From the little I know about metaprogramming, it sounds analogous to doing string manipulations in a language, and then eval'ing it (which is heavily frowned up

• andreasvc 13y ago
  Because here you're not doing string manipulation, but AST manipulation (i.e., the datastructure you get after parsing the language).
• skybrian 13y ago
  It's a bit higher level, roughly like generating HTML using a templating library that auto-escapes to avoid XSS attacks. There are fewer ways to screw up and since it happens at compile-time, it's more secure. Generally speaking, if you would normally do something using reflection, you can also do it using code generation, which should compile to faster code (since you're not interpreting it at runtime) but possibly at the cost of code bloat and making the code harder to follow.
• chipsy 13y ago
  If you're familiar with front-end web coding, it's comparable to manipulating the properties of DOM objects vs. assigning an innerHTML string. Building a string is crude but sometimes effective - but when you want to really engineer something, you want to have every node made available as a data structure, since that puts it in a form suitable for algorithm design. In a lot of instances, a macro isn't particularly more complicated in intent than a string + eval solution; it's just a much more verbose way of attacking the problem.