► |  | The Racket Reference

1 | Language Model
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
| Bibliography
| Index

► | 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

▼ | 12.7 | Reader Extension

12.7.1 | Readtables
12.7.2 | Reader-Extension Procedures
12.7.3 | Special Comments

On this page:

make-special-comment
special-comment?
special-comment-value

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##### 12.7.3`` Special Comments

> procedure (make-special-comment v) → special-comment?
> v : any/c

Creates a special-comment value that encapsulates v. The read, read-syntax, etc., procedures treat values constructed with make-special-comment as delimiting whitespace when returned by a reader-extension procedure (see Reader-Extension Procedures).

> procedure (special-comment? v) → boolean?
> v : any/c

Returns #t if v is the result of make-special-comment, #f otherwise.

> procedure (special-comment-value sc) → any
> sc : special-comment?

Returns the value encapsulated by the special-comment value sc. This value is never used directly by a reader, but it might be used by the context of a read-char-or-special, etc., call that detects a special comment.
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