Programming

I spend my time (recently) writing a mishmash of Python, C++, and Java. It’s interesting to switch back and forth.

What’s a good idea and what’s a bad (or dangerous) idea in computer language design? We’ve got a lot of candidates, and a lot of opinions.

I’ll list a few here, along with a few places where they show up. I’m not saying C macros are the same as, or even similar to, Lisp macros. Just trying to clarify the spectrum.

I’ve heard someone, at some point, say each one of the items below is a good idea / bad idea. Dangerous in the hands of a novice? Yes, but then so is any computer with a network connection.

• Preprocessors (C, C++)
• Macros (C, Lisp)
• Multiple Inheritance (C++, Smalltalk)
• Operator Overloading (C++, Python)
• Closures (Lisp, Haskell)
• Generics (Java, Ada)
• Template Metaprogramming (C++)
• Casts (C, C++)
• Strong or Weak Typing (Scala, Lisp, Python, ML)
• Fixed-Point Math (C# and COBOL)
• Fixed Integer Types vs. “Numbers” (C, Lisp, Python)
• Garbage Collection (Java, Lisp, ML)
• Manual Allocation / Deallocation (C, C++)
• Everything is an Object / Some Things are Primitives (Smalltalk, Java)
• Auto-(Un)Boxing (Java, C#)
• Indentation is Significant (Python)
• First-Order Functions (ML, Lisp)
• Lambdas (ML, Lisp, Python)
• Type Erasure (Java)

Did I leave out your favorite / most reviled language feature? Complain below. I included type erasure at the end of the list. Does anyone think this was a good idea for Java???