suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

improve docs on printer modes

Browse Source
This commit is contained in:
Matthew Flatt 2010-05-09 07:05:08 -06:00
parent d9917b27a0
commit f24d66f02f
1 changed files with 21 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
collects/scribblings/reference/printer.scrbl
View File

@ -4,27 +4,39 @@
@title[#:tag "printing" #:style 'quiet]{The Printer}
The Racket printer support three modes:
The Racket printer supports three modes:
@itemlist[
@item{@racket[print] mode by default prints most datatypes in such a
way that evaluating the output as an expression produces a
value that is @racket[equal?] to the printed value;}
@item{@racket[write] mode prints core datatypes in such a way that
using @racket[read] on the output produces a value that is
@racket[equal?] to the printed value; when
@racket[print-as-expression] is set to @racket[#f], then
@racket[print] mode is like @racket[write] mode;}
@racket[equal?] to the printed value;}
@item{@racket[display] mode prints core datatypes is a form in a more
``end-user'' style rather than ``programmer' style; for
example, a string @racket[display]s as its content characters
without surrounding @litchar{"}s or escapes.}
without surrounding @litchar{"}s or escapes;}
@item{@racket[print] mode by default---when
@scheme[print-as-expression] is @scheme[#t]---prints most
datatypes in such a way that evaluating the output as an
expression produces a value that is @racket[equal?] to the
printed value; when @racket[print-as-expression] is set to
@racket[#f], then @racket[print] mode is like @racket[write]
mode.}
]
In @racket[print] mode when @racket[print-as-expression] is
@scheme[#t] (as is the default), a value prints at a @deftech{quoting
depth} of either @scheme[0] (unquoted) or @scheme[1] (quoted). The
initial quoting depth is accepted as an optional argument by
@racket[print], and printing of some compound datatypes adjusts the
print depth for component values. For example, when a list is printed
at quoting depth @scheme[0] and all of its elements are
@deftech{quotable}, the list is printed with a @litchar{'} prefix, and
the list's elements are printed at quoting depth @scheme[1].
When the @scheme[print-graph] parameter is set to @scheme[#t], then
the printer first scans an object to detect cycles. The scan traverses
the components of pairs, mutable pairs, vectors, boxes (when
@ -44,16 +56,6 @@ terms of Unicode characters; see @secref["ports"] for information
on how a character stream is written to an port's underlying byte
stream.
In @racket[print] mode when @racket[print-as-expression] is
@scheme[#t] (as is the default), a value prints at a @deftech{quoting
depth} of either @scheme[0] (unquoted) or @scheme[1] (quoted). The
initial quoting depth is accepted as an optional argument by
@racket[print], and printing of some compound datatypes adjusts the
print depth for component values. For example, when a list is printed
at quoting depth @scheme[0] and all of its elements are
@deftech{quotable}, the list is printed with a @litchar{'} prefix, and
the list's elements are printed at quoting depth @scheme[1].
@section[#:tag "print-symbol"]{Printing Symbols}