1.2 L features

L has numerous features that makes it a cool language to hack with. Among them:

• L is a compiled language. It can thus run very fast. Compilation allows to track your errors sooner, and execution is faster than with other techniques. L programs can have very low memory footprint. L can sometimes outperfom C; for instance, its type system allows more agressive memory aliasing.
• L is interactive. Speed up your developpement by not using the “edit-compile-test” cycle developpement process. Write part of a function and immediately test it. Interactively compiling functions is very fast, so you don't have to wait for long compile/link cycles.
• L is extensible. If you need anything to add in the language you don't need to wait for 10 years that a committee decide to enhance the language. You just do it. Extensibility is at the heart of L programming, and is a programmation paradigm in itself.
• L is multi-paradigm. L's extensibility allows to write programs using different paradigm at the same time. I.e., you can freely mix functional, imperative, and object-oriented code.
• L has a flexible type system. Types are there to help you and automatically manage things for you; they don't get in your way.
• L helps you write safe programs. Traditionnal languages are split between too extremes:
  • Safe languages. Unfortunately, clever optimisations aren't allowed with them.
  • Unsafe language, like C. They allow to write any code, but programs written with them often crash or lead to security issues.

  With L, it is easy to write safe programs with some confined unsafe parts. Just write the unsafe parts carefully, and your program will be both optimized and won't crash.

  For instance, you can use pointers (both powerful and unsafe), but L provides many ways to avoid their use (for instance using Tuples, and multiple return values) or confine them (using macros, like the foreach macro for iterating on lists).

• L interfaces well with C. You can directly use C libraries from L, and use L libraries from C. No need to write long wrappers for that.
• L enables extreme factorisation of your programs. Typical L programs are a lot smaller than equivalent C programs. As such, they are easier to understand as a whole.

  As a corollary, with L, you can optimize your program without sacrificing readability. Dirty hacks can be confined and factorised. If you later change your mind about a hack, you just have to change one place, something that is not always possible e.g. in C.