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2 | Syntactic Forms
3 | Datatypes
4 | Structures
5 | Classes and Objects
6 | Units
7 | Contracts
8 | Pattern Matching
9 | Control Flow
10 | Concurrency and Parallelism
11 | Macros
12 | Input and Output
13 | Reflection and Security
14 | Operating System
15 | Memory Management
16 | Unsafe Operations
17 | Running Racket
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▼ | 12 | Input and Output

12.1 | Ports
12.2 | Byte and String Input
12.3 | Byte and String Output
12.4 | Reading
12.5 | Writing
12.6 | Pretty Printing
12.7 | Reader Extension
12.8 | Printer Extension
12.9 | Serialization
12.10 | Fast-Load Serialization

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s-exp->fasl
fasl->s-exp

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#### 12.10`` Fast-Load Serialization

(require racket/fasl)

The bindings documented in this section are provided by the racket/fasl library, not racket/base or racket.

> procedure (s-exp->fasl v [out]) → (or/c (void) bytes?)
> v : any/c
> out : (or/c output-port? #f) = #f
> procedure (fasl->s-exp in) → any/c
> in : (or/c input-port? bytes?)

The s-exp->fasl function serializes v to a byte string, printing it directly to out if out is an output port or return the byte string otherwise. The fasl->s-exp function decodes a value from a byte string (supplied either directly or as an input port) that was encoded with s-exp->fasl.

The v argument must be a value that could be quoted as a literal, because s-exp->fasl essentially uses (compile `',v) to encode the value using Racket’s built-in fast-load format for bytecode.

The byte-string encoding produced by s-exp->fasl is specific to a version of Racket. That is, the resulting byte string can be decoded back to v only using the same version with which it was encoded.

Examples:
> > (define fasl (s-exp->fasl (list #("speed") 'racer #\!)))
> > fasl
> #"#~\0035.3T\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1\0\0\0\1\0\0\0\0\36\0\0\0\237$\24q\237$\20\0\20\0\25_\20\1\6\5\5speedAracer\a!"
> > (fasl->s-exp fasl)
> '(#("speed") racer #\!)

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