# Chapter 0: Genesis

This chapter explains the core value representation of Zisp, and goes
through the processes of parsing, decoding, running, and optionally
compiling code.

0. [Value](0-value.html)

   Zisp uses a uniform 64-bit representation for all values, densely
   packed into signaling or non-canonical NaN values.

1. [Parse](1-parse.html) (see also [grammar](grammar/))

   The parser receives a stream of bytes and transforms them into a
   minimal set of data types with very little processing.

2. [Decode](2-decode.html)

   The decoder runs configurable and extensible pre-processing steps
   over data received from the parser, enriching it with more complex
   value types, and handling primitive source code transforms.

3. [Eval](3-eval.html)

   Code is evaluated within a mutable module context, on which it can
   have side effects such as creating new definitions or establishing
   links to other modules.

4. [Compile](4-compile.html)

   Procedures from within the compiler module can be used to demand
   the compilation of other modules, with various options, yielding
   static or dynamic object files.  These may be loaded immediately,
   replacing the previously uncompiled module code in memory.