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make-special-comment
special-comment?
special-comment-value
Version: 4.2.1
12.9.3 Special Comments

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).

(special-comment? v)  boolean?
  v : any/c
Returns #t if v is the result of make-special-comment, #f otherwise.

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.