Author: peter.seibel
Date: Wed Mar 7 22:20:05 2007
New Revision: 12
Modified:
trunk/faq.txt
trunk/lispfaq.txt
Log:
Reorging lispfaq a bit and moving READ-FROM-STRING question into faq.
Modified: trunk/faq.txt
==============================================================================
--- trunk/faq.txt (original)
+++ trunk/faq.txt Wed Mar 7 22:20:05 2007
@@ -824,6 +824,28 @@
(map-into (make-array 10) #'make-foo)
+*** Why does (read-from-string "foobar" :start 3) return FOOBAR instead of BAR?
+
+\cl{READ-FROM-STRING} is one of the rare functions that takes both
+\code{&optional} and \code{&key} arguments. The complete argument list is:
+
+ string &optional eof-error-p eof-value &key :start :end
:preserve-whitespace
+
+When a function takes both types of arguments, all the optional
+arguments must be specified explicitly before any of the keyword
+arguments may be specified. In the example above, :\code{start}
+becomes the value of the optional \code{eof-error-p} parameter and 3
+is the value of the optional \code{eof-value} parameter.
+
+To get the desired result, you should use \code{(read-from-string
+"foobar" t nil :start 3)}.
+
+There are only three other functions in the COMMON-LISP package that
+take both \code{&optional} and \code{&key} arguments and thus are
+potentially subject to the same problem: \cl{PARSE-NAMESTRING},
+\cl{WRITE-LINE} and \cl{WRITE-STRING}.
+
+
** Why doesn't Lisp ...
*** Why doesn't Common Lisp have continuations?
Modified: trunk/lispfaq.txt
==============================================================================
--- trunk/lispfaq.txt (original)
+++ trunk/lispfaq.txt Wed Mar 7 22:20:05 2007
@@ -6,7 +6,7 @@
Marsden's attempt to clean up the old comp.lang.lisp FAQ. (Last
updated: \datestamp{})}
-** FAQ
+** Possibly useful
*** What is the Lisp equivalent of the \symbol{__FILE__} and \symbol{__LINE__}
\acronym{ANSI} C preprocessor macros? How do I find out where an error
occurred?
@@ -201,59 +201,6 @@
Something which is closer to the canonical "Hello, World!" attempt is
\userinput{ (write-line "Hello, World!") }
-*** Can you help me with my homework?
-
-But of course!
-
-However, we will need the e-mail address of your lecturer or teaching
-instructor to best aid you; for it is only fair that if we do the
-homework we should get the course credits. Alternatively, should you
-wish to hire a consultant from the group, competitive rates can be
-arranged.
-
-Post the assignment, and your attempt so far; state explicitly that it
-is homework. You may find a kind soul on the group to explain some
-point that you are missing; this is more likely the more visible your
-own work is. Posts of the form "my assignment is due tomorrow please
-hlep!" are unlikely to engender much sympathy.
-
-*** How do I manipulate symbols with IMPLODE/EXPLODE?
-
-Generally, you don't.
-
-IMPLODE and EXPLODE were functions in old lisps where there was no
-string data type, so that symbols were the only way of manipulating
-text. Then (explode 'foo) would give you (F O O); you could then do
-(implode (cdr (explode 'crash))) to give you back the symbol RASH
-
-If you are taught today about implode/explode in a lisp programming
-class for anything other than historical context, complain loudly to
-your lecturer.
-
-*** What is off-topic on comp.lang.lisp?
-
-Questions about Scheme, Emacs Lisp and AutoLisp tend not to be
-terribly welcome, as they have their own fora in the
-\link{\href{news:comp.lang.scheme}\text{comp.lang.scheme}},
-\link{\href{comp.emacs}\text{comp.emacs}} and
-\link{\href{comp.cad.autocad}\text{comp.cad.autocad}} newsgroups.
-
-*** What is on-topic on comp.lang.lisp?
-
-Discussion of the language defined by the ANSI Common Lisp standard is
-definitely on-topic on comp.lang.lisp. Unlike comp.lang.c, we do not
-restrict our discussions to the standard, but also actively discuss
-the differences between implementations and implementation-specific
-extensions.
-
-Since the Lisp community is remarkably long-lived, discussion of the
-history and evolution of Lisp tends also to be welcomed, or at least
-tolerated; discussion of non-standard lisps (though generally not
-Scheme or Emacs Lisp) is also accepted. Though \acronym{CLOS} (the
-Common Lisp Object System) has \link{\href{news:comp.lang.lisp.clos}
-\text{its own newsgroup}} it is also part of ANSI CL, and so is a
-valid topic for discussion.
-
*** What online resources are there for lisp users?
\variablelist{\varlistentry{\term{\link{\href{http://www.lispworks.com/reference/HyperSpec/Front/}
@@ -306,51 +253,6 @@
}}\listitem{\para{A commercial natively multithreaded implementation of
Common Lisp for various Unixes.}}}\varlistentry{\term{Symbolics Common
Lisp}\listitem{\para{} }}}
-*** What is the purpose of \link{\href{news:comp.lang.lisp}
-\text{comp.lang.lisp}
-
-}?
-
-The charter at
-\link{\href{ftp://ftp.uu.net/usenet/control/comp/comp.lang.lisp}
-\text{ftp://ftp.uu.net/usenet/control/comp/comp.lang.lisp}} states
-that the purpose of comp.lang.lisp is "Discussion about LISP". It is
-somewhat in the nature of things that newsgroups' purposes evolve, as
-do names. Firstly, the newsgroup has evolved such that the main topic
-of discussion is ANSI Common Lisp, though discussion about other lisp
-variants is welcome within reasonable bounds. Secondly, the spelling
-"LISP" is passé; while it does reflect the initial abbreviation, it no
-longer reflects the actual language, so "Lisp" is the preferred
-capitalization.
-
-*** Why does (read-from-string "foobar" :start 3) return FOOBAR instead of BAR?
-
-\cl{READ-FROM-STRING} is one of the rare functions that takes both
-&OPTIONAL and &KEY arguments: \literallayout{\cl{READ-FROM-STRING}
-string &OPTIONAL eof-error-p eof-value &KEY :start :end
-:preserve-whitespace }
-
-When a function takes both types of arguments, all the optional
-arguments must be specified explicitly before any of the keyword
-arguments may be specified. In the example above, :START becomes the
-value of the optional EOF-ERROR-P parameter and 3 is the value of the
-optional EOF-VALUE parameter.
-
-To get the desired result, you should use \command{(read-from-string
-"foobar" t nil :start 3)}. If you need to understand and use the
-optional arguments, please refer to CLTL2 under READ-FROM-STRING,
-otherwise, this will behave as desired for most purposes.
-
-The other functions with this peculiarity in the COMMON-LISP package
-are \cl{PARSE-NAMESTRING}, \cl{WRITE-LINE} and \cl{WRITE-STRING}.
-
-*** How does \userinput{(defun car (x) (car x))} work?
-
-This code is probably part of the source to a lisp compiler, which
-knows how to open-code calls to CAR. However, the interpreter also
-needs to know how to call CAR, which is what the above defun is doing.
-This is not recommended in user code...
-
*** The read-eval-print loop is just sitting there after I've typed in my
form. What's happening?
One possible explanation for this behaviour is that you have typed in
@@ -365,6 +267,7 @@
or right parenthesis, respectively. Try typing a few right parentheses
followed by Return.
+*** How do I run my programme as a script, then?
*** Is Scheme a lisp?
Scheme is a member of the greater family of Lisp languages, assuming
@@ -379,7 +282,6 @@
\text{comp.lang.scheme}}, where discussion would be much more welcome
and appropriate.
-*** How do I run my programme as a script, then?
*** How do I split a string?
@@ -414,5 +316,80 @@
To avoid this, use the :predicate defstruct option to eliminate or
rename the predicate function, or else use a different slot name.
+** Probably obsolete
+
+*** How do I manipulate symbols with IMPLODE/EXPLODE?
+
+Generally, you don't.
+
+IMPLODE and EXPLODE were functions in old lisps where there was no
+string data type, so that symbols were the only way of manipulating
+text. Then (explode 'foo) would give you (F O O); you could then do
+(implode (cdr (explode 'crash))) to give you back the symbol RASH
+
+If you are taught today about implode/explode in a lisp programming
+class for anything other than historical context, complain loudly to
+your lecturer.
+
+*** How does \userinput{(defun car (x) (car x))} work?
+
+This code is probably part of the source to a lisp compiler, which
+knows how to open-code calls to CAR. However, the interpreter also
+needs to know how to call CAR, which is what the above defun is doing.
+This is not recommended in user code...
+
+*** What is the purpose of comp.lang.lisp?
+
+The charter at
+\link{\href{ftp://ftp.uu.net/usenet/control/comp/comp.lang.lisp}
+\text{ftp://ftp.uu.net/usenet/control/comp/comp.lang.lisp}} states
+that the purpose of comp.lang.lisp is "Discussion about LISP". It is
+somewhat in the nature of things that newsgroups' purposes evolve, as
+do names. Firstly, the newsgroup has evolved such that the main topic
+of discussion is ANSI Common Lisp, though discussion about other lisp
+variants is welcome within reasonable bounds. Secondly, the spelling
+"LISP" is passé; while it does reflect the initial abbreviation, it no
+longer reflects the actual language, so "Lisp" is the preferred
+capitalization.
+
+*** What is off-topic on comp.lang.lisp?
+
+Questions about Scheme, Emacs Lisp and AutoLisp tend not to be
+terribly welcome, as they have their own fora in the
+\link{\href{news:comp.lang.scheme}\text{comp.lang.scheme}},
+\link{\href{comp.emacs}\text{comp.emacs}} and
+\link{\href{comp.cad.autocad}\text{comp.cad.autocad}} newsgroups.
+
+*** What is on-topic on comp.lang.lisp?
+
+Discussion of the language defined by the ANSI Common Lisp standard is
+definitely on-topic on comp.lang.lisp. Unlike comp.lang.c, we do not
+restrict our discussions to the standard, but also actively discuss
+the differences between implementations and implementation-specific
+extensions.
+
+Since the Lisp community is remarkably long-lived, discussion of the
+history and evolution of Lisp tends also to be welcomed, or at least
+tolerated; discussion of non-standard lisps (though generally not
+Scheme or Emacs Lisp) is also accepted. Though \acronym{CLOS} (the
+Common Lisp Object System) has \link{\href{news:comp.lang.lisp.clos}
+\text{its own newsgroup}} it is also part of ANSI CL, and so is a
+valid topic for discussion.
+
+
+*** Can you help me with my homework?
+
+But of course!
+However, we will need the e-mail address of your lecturer or teaching
+instructor to best aid you; for it is only fair that if we do the
+homework we should get the course credits. Alternatively, should you
+wish to hire a consultant from the group, competitive rates can be
+arranged.
+
+Post the assignment, and your attempt so far; state explicitly that it
+is homework. You may find a kind soul on the group to explain some
+point that you are missing; this is more likely the more visible your
+own work is. Posts of the form "my assignment is due tomorrow please
+hlep!" are unlikely to engender much sympathy.
_______________________________________________
cl-faq mailing list
cl-faq@lispniks.com
http://www.lispniks.com/mailman/listinfo/cl-faq
