82 lines
5.3 KiB
HTML
82 lines
5.3 KiB
HTML
<!-- Common Lisp HyperSpec (TM), version 7.0 generated by Kent M. Pitman on Mon, 11-Apr-2005 2:31am EDT -->
|
|
<HTML>
|
|
<HEAD>
|
|
<TITLE>CLHS: Variable *PRINT-PRETTY*</TITLE>
|
|
<LINK HREF="../Data/clhs.css" REL="stylesheet" TYPE="text/css" />
|
|
<META HTTP-EQUIV="Author" CONTENT="Kent M. Pitman">
|
|
<META HTTP-EQUIV="Organization" CONTENT="LispWorks Ltd.">
|
|
<LINK REL=TOP HREF="../Front/index.htm">
|
|
<LINK REL=COPYRIGHT HREF="../Front/Help.htm#Legal">
|
|
<LINK REL=DISCLAIMER HREF="../Front/Help.htm#Disclaimer">
|
|
<LINK REL=PREV HREF="v_pr_ppr.htm">
|
|
<LINK REL=UP HREF="c_printe.htm">
|
|
<LINK REL=NEXT HREF="v_pr_rda.htm">
|
|
</HEAD>
|
|
<BODY>
|
|
<H1><A REV=MADE HREF="http://www.lispworks.com/"><IMG WIDTH=80 HEIGHT=65 ALT="[LISPWORKS]" SRC="../Graphics/LWSmall.gif" ALIGN=Bottom></A><A REL=TOP HREF="../Front/index.htm"><IMG WIDTH=237 HEIGHT=65 ALT="[Common Lisp HyperSpec (TM)]" SRC="../Graphics/CLHS_Sm.gif" ALIGN=Bottom></A> <A REL=PREV HREF="v_pr_ppr.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Previous]" SRC="../Graphics/Prev.gif" ALIGN=Bottom></A><A REL=UP HREF="c_printe.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Up]" SRC="../Graphics/Up.gif" ALIGN=Bottom></A><A REL=NEXT HREF="v_pr_rda.htm"><IMG WIDTH=40 HEIGHT=40 ALT="[Next]" SRC="../Graphics/Next.gif" ALIGN=Bottom></A></H1>
|
|
|
|
<HR>
|
|
|
|
<A NAME="STprint-prettyST"><I>Variable</I> <B>*PRINT-PRETTY*</B></A> <P>
|
|
<P><B>Value Type:</B><P>
|
|
<P>
|
|
a <A REL=DEFINITION HREF="26_glo_g.htm#generalized_boolean"><I>generalized boolean</I></A>. <P>
|
|
<P><B>Initial Value:</B><P>
|
|
<P>
|
|
<A REL=DEFINITION HREF="26_glo_i.htm#implementation-dependent"><I>implementation-dependent</I></A>. <P>
|
|
<P><B>Description:</B><P>
|
|
<P>
|
|
Controls whether the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_printer"><I>Lisp printer</I></A> calls the <A REL=DEFINITION HREF="26_glo_p.htm#pretty_printer"><I>pretty printer</I></A>. <P>
|
|
If it is <A REL=DEFINITION HREF="26_glo_f.htm#false"><I>false</I></A>, the <A REL=DEFINITION HREF="26_glo_p.htm#pretty_printer"><I>pretty printer</I></A> is not used and a minimum of <A REL=DEFINITION HREF="26_glo_w.htm#whitespace"><I>whitespace</I></A>[1] is output when printing an expression. <P>
|
|
If it is <A REL=DEFINITION HREF="26_glo_t.htm#true"><I>true</I></A>, the <A REL=DEFINITION HREF="26_glo_p.htm#pretty_printer"><I>pretty printer</I></A> is used, and the <A REL=DEFINITION HREF="26_glo_l.htm#lisp_printer"><I>Lisp printer</I></A> will endeavor to insert extra <A REL=DEFINITION HREF="26_glo_w.htm#whitespace"><I>whitespace</I></A>[1] where appropriate to make <A REL=DEFINITION HREF="26_glo_e.htm#expression"><I>expressions</I></A> more readable. <P>
|
|
<A REL=DEFINITION HREF="#STprint-prettyST"><B>*print-pretty*</B></A> has an effect even when the <A REL=DEFINITION HREF="26_glo_v.htm#value"><I>value</I></A> of <A REL=DEFINITION HREF="v_pr_esc.htm#STprint-escapeST"><B>*print-escape*</B></A> is <A REL=DEFINITION HREF="26_glo_f.htm#false"><I>false</I></A>. <P>
|
|
<P><B>Examples:</B><P>
|
|
<P>
|
|
|
|
<PRE>
|
|
(setq *print-pretty* 'nil) => NIL
|
|
(progn (write '(let ((a 1) (b 2) (c 3)) (+ a b c))) nil)
|
|
>> (LET ((A 1) (B 2) (C 3)) (+ A B C))
|
|
=> NIL
|
|
(let ((*print-pretty* t))
|
|
(progn (write '(let ((a 1) (b 2) (c 3)) (+ a b c))) nil))
|
|
>> (LET ((A 1)
|
|
>> (B 2)
|
|
>> (C 3))
|
|
>> (+ A B C))
|
|
=> NIL
|
|
;; Note that the first two expressions printed by this next form
|
|
;; differ from the second two only in whether escape characters are printed.
|
|
;; In all four cases, extra whitespace is inserted by the pretty printer.
|
|
(flet ((test (x)
|
|
(let ((*print-pretty* t))
|
|
(print x)
|
|
(format t "~%~S " x)
|
|
(terpri) (princ x) (princ " ")
|
|
(format t "~%~A " x))))
|
|
(test '#'(lambda () (list "a" #'c #'d))))
|
|
>> #'(LAMBDA ()
|
|
>> (LIST "a" #'C #'D))
|
|
>> #'(LAMBDA ()
|
|
>> (LIST "a" #'C #'D))
|
|
>> #'(LAMBDA ()
|
|
>> (LIST a b 'C #'D))
|
|
>> #'(LAMBDA ()
|
|
>> (LIST a b 'C #'D))
|
|
=> NIL
|
|
</PRE>
|
|
</TT> <P>
|
|
<P><B>Affected By:</B> None.
|
|
<P>
|
|
<P><B>See Also:</B><P>
|
|
<P>
|
|
<A REL=DEFINITION HREF="f_wr_pr.htm#write"><B>write</B></A> <P>
|
|
<P><B>Notes:</B> None.
|
|
<P>
|
|
<P><HR>The following <A REL=META HREF="../Front/X3J13Iss.htm">X3J13 cleanup issues</A>, <I>not part of the specification</I>, apply to this section:<P><UL><LI> <A REL=CHILD HREF="../Issues/iss169.htm">FORMAT-PRETTY-PRINT:YES</A><LI> <A REL=CHILD HREF="../Issues/iss277.htm">PRINTER-WHITESPACE:JUST-ONE-SPACE</A><P></UL><HR>
|
|
|
|
<A REL=NAVIGATOR HREF="../Front/StartPts.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Starting Points]" SRC="../Graphics/StartPts.gif" ALIGN=Bottom></A><A REL=TOC HREF="../Front/Contents.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Contents]" SRC="../Graphics/Contents.gif" ALIGN=Bottom></A><A REL=INDEX HREF="../Front/X_Master.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Index]" SRC="../Graphics/Index.gif" ALIGN=Bottom></A><A REL=INDEX HREF="../Front/X_Symbol.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Symbols]" SRC="../Graphics/Symbols.gif" ALIGN=Bottom></A><A REL=GLOSSARY HREF="../Body/26_a.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Glossary]" SRC="../Graphics/Glossary.gif" ALIGN=Bottom></A><A HREF="../Front/X3J13Iss.htm"><IMG WIDTH=80 HEIGHT=40 ALT="[Issues]" SRC="../Graphics/Issues.gif" ALIGN=Bottom></A><BR>
|
|
|
|
<A REL=COPYRIGHT HREF="../Front/Help.htm#Legal"><I>Copyright 1996-2005, LispWorks Ltd. All rights reserved.</I></A><P>
|
|
</BODY>
|
|
</HTML>
|