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README : The Hamster BF Compiler v0.04
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Jon Simons (simonsj at the domain ccs dot neu dot edu)
November, 2008
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The Hamster BF compiler is the world's most diverse, highly-optimizing,
well-commented, and modularly designed BF compiler ever implemented.

Hamster was written because I wanted to code something in Scheme, and I
think that the idea of a highly-optimizing BF compiler which can emit a
perverse number of target languages is rather hilarious.

The source code is arranged as follows:

  bf-lex.scm               The lexing module.  Lexes tokens from an
                           input file.

  bf-parser.scm            The parsing module.  Converts lexed tokens
                           into a BF AST via a hand-written recursive
                           descent parser.

  bf-ast-to-ir.scm         The AST -> IR translation module.  Defines
                           a BF Intermediate Representation and provides
                           an ast->ir transformation function.

  optimizations/           This directory contains IR optimization
                           modules.  Each module exports a function
                           mapping IR -> IR, and contains a detailed
                           description of the optimization that it
                           performs.

    ops.scm                A single point of inclusion for all of the
                           optimization files.

    collapse-mults.scm     Collapses multiplication loops.
    collapse-zeroes.scm    Collapses zero loops.
    dead-loops.scm         Eliminates dead loops.

  emitters/                This directory contains code-emitter modules
                           for all of the target languages.

    bf-emit-ir.scm         BF Intermediate Representation
    bf-emit-c.scm          ANSI C
    bf-emit-java.scm       Java
    bf-emit-mips.scm       MIPS Assembly
    bf-emit-x86m.scm       MASM x86 Assembly (16-bit for DOS)
    bf-emit-llvm.scm       LLVM Assembly

  bf-compiler.scm          Contains the main entry point.  Imports lexing,
                           parsing, IR transformation, and target language
                           emitter modules.

The source code is full of great comments, ready for your viewing pleasure.

Running the compiler requires MzScheme version 4, which can be downloaded
here:

  http://www.plt-scheme.org/software/mzscheme/

The command I use to run the compiler is:

  mzscheme bf-compiler.scm

If you'd like more information on the BF language, the Esolang Wiki is
an excellent source:

  http://www.esolangs.org/wiki/Brainfuck

That's all.