===========================================
         Questions and Answers
===========================================


General
=======

What is Nim?
------------

Nim (formerly known as "Nimrod") is a statically typed, imperative programming
language that tries to give the programmer ultimate power without compromises
on runtime efficiency.
This means it focuses on compile-time mechanisms in all their
various forms. Beneath a nice infix/indentation based syntax with a 
powerful (AST based, hygienic) macro system lies a semantic model that supports 
a soft realtime GC on thread local heaps. Asynchronous message passing is used 
between threads, so no "stop the world" mechanism is necessary. An unsafe 
shared memory heap is also provided for the increased efficiency that results 
from that model.


Why yet another programming language?
-------------------------------------

Nim is one of the very few *programmable* statically typed languages, and 
one of the even fewer that produces native binaries that require no 
runtime or interpreter.


What have been the major influences in the language's design?
-------------------------------------------------------------

The language borrows heavily from (in order of impact): Modula 3, Delphi, Ada,
C++, Python, Lisp, Oberon.



What is Nim's take on concurrency?
----------------------------------

Nim primarily focusses on thread local (and garbage collected) heaps and 
message passing between threads. Each thread has its own GC, so no 
"stop the world" mechanism is necessary. An unsafe shared memory heap is also
provided.

Future versions will additionally include a GC "per thread group" 
and Nim's type system will be enhanced to accurately model this shared
memory heap.


How is Nim licensed?
--------------------

The Nim compiler and the library are MIT licensed.
This means that you can use any license for your own programs developed with
Nim.


How stable is Nim?
------------------

The compiler is in development and some important features are still missing.
However, the compiler is quite stable already: It is able to compile itself 
and a substantial body of other code. Until version 1.0.0 is released,
minor incompatibilities with older versions of the compiler will be introduced.


How fast is Nim?
----------------
Benchmarks show it to be comparable to C. Some language features (methods, 
closures, message passing) are not yet as optimized as they could and will be.
The only overhead Nim has over C is the GC which has been tuned 
for years but still needs some work.


What about JVM/CLR backends?
----------------------------

A JVM backend is almost impossible. The JVM is not expressive enough. It has
never been designed as a general purpose VM anyway. A CLR backend is possible
but would require much work. 

What about editor support?
--------------------------

- Nim IDE: https://github.com/nimrod-code/Aporia
- Emacs: https://github.com/Tass/nimrod-mode
- Vim: https://github.com/zah/nimrod.vim/
- Scite: Included
- Gedit: The `Aporia .lang file <https://github.com/nimrod-code/Aporia/blob/master/share/gtksourceview-2.0/language-specs/nimrod.lang>`_
- jEdit: https://github.com/exhu/nimrod-misc/tree/master/jedit


Why is it named ``proc``?
-------------------------

*Procedure* used to be the common term as opposed to a *function* which is a
mathematical entity that has no side effects. It was planned to have ``func``
as syntactic sugar for ``proc {.noSideEffect.}`` but with the more fine-grained
effect system it is not yet clear what ``func`` should be a shortcut for.


Compilation
===========

Which option to use for the fastest executable?
-----------------------------------------------

For the standard configuration file, ``-d:release`` does the trick.


Which option to use for the smallest executable?
------------------------------------------------

For the standard configuration file, ``-d:quick --opt:size`` does the trick.


How do I use a different C compiler than the default one?
---------------------------------------------------------

Edit the ``config/nimrod.cfg`` file.
Change the value of the ``cc`` variable to one of the following:

==============  ============================================
Abbreviation    C/C++ Compiler
==============  ============================================
``vcc``         Microsoft's Visual C++
``gcc``         Gnu C
``llvm_gcc``    LLVM-GCC compiler
``icc``         Intel C++ compiler
``clang``       Clang compiler
``ucc``         Generic UNIX C compiler
==============  ============================================

Other C compilers are not officially supported, but might work too.

If your C compiler is not in the above list, try using the
*generic UNIX C compiler* (``ucc``). If the C compiler needs
different command line arguments try the ``--passc`` and ``--passl`` switches.
