is there a simple compiler for a small language

Question

I am looking for a simple compiler that compiles a simple language, I need it to write a paper about it and to learn how compilers work, I am not looking for a sophisticated thi

Answer 1

There are a lot you can use, what you will find easiest will depend on your experience.

Firstly as regards the language:

1. The simplest is a toy language, for example compiling an arithmetic expressions.
2. Next is an assembler - again really just translating but shows the basics of parsing and turning into op-codes
3. Next is probably something like C, which is very close to pure assembler, or something like LISP which is very close to pure theory.

Next, choosing your compiler.

You could start with an assembler - turning assembler into machine code. This was the first step in producing compilers - I'd suggest for a chip like the 6502 or 8080 which are both very simple. Something like the assembler's development kit might work well for you (it comes with examples)

Many people (including me) would argue the easiest languages to write compilers in are functional - nowadays that probably means Haskell, Scheme or Common Lisp. An example of how easy it is is this blog post. He writes a compiler that just compiles arithmetic expressions in a few lines. This might be minimal enough for you.

Almost every introduction to writing compilers at the academic level starts with a minimal language as an example, the Dragon Book http://en.wikipedia.org/wiki/Dragon_Book_%28computer_science%29 is always recommended, but there are other good ones.

At University I used C-- which is like C but even easier to write a compiler for. Lots of resources at: http://www.cminusminus.org/qc--.html

If you wanted a compiler and you know a language like Java I'd suggest something like JavaCC, where the language is specified using grammars. There are lots of example grammars here - pick something simple like C to get started.