11:04 a.m.
changeset: 5359:f5a5501814f5
tag: tip
user: Aidan Kehoe <kehoea(a)parhasard.net>
date: Sat Feb 19 11:03:46 2011 +0000
files: man/ChangeLog man/lispref/lists.texi man/lispref/objects.texi src/ChangeLog
src/fns.c
description:
Document the CL set functions and #'eql in the Lispref, not just cl.texi
man/ChangeLog addition:
2011-02-19 Aidan Kehoe <kehoea(a)parhasard.net>
* lispref/lists.texi (Sets And Lists):
Document #'member*, #'remove*, #'delete* in this file. Document
#'memq, #'member, #'remq, #'remove, #'delq, #'delete in terms of
the former functions.
Document #'subsetp, #'union, #'intersection, #'set-difference,
#'set-exclusive-or and their destructive analogues in this file.
* lispref/lists.texi (Association Lists):
Document #'assoc*, #'rassoc* in this file. Document #'assq,
#'assoc, #'rassq, #'rassoc in terms of the first two functions.
* lispref/objects.texi (Equality Predicates):
Document #'eql here, don't leave it to cl.texi.
src/ChangeLog addition:
2011-02-19 Aidan Kehoe <kehoea(a)parhasard.net>
* fns.c (Fset_exclusive_or):
This function accepts the :stable keyword too, document this in
its arglist.
diff -r 31475de17064 -r f5a5501814f5 man/ChangeLog
--- a/man/ChangeLog Wed Feb 16 18:26:40 2011 +0000
+++ b/man/ChangeLog Sat Feb 19 11:03:46 2011 +0000
＠＠ -1,3 +1,17 ＠＠
+2011-02-19 Aidan Kehoe <kehoea(a)parhasard.net>
+
+ * lispref/lists.texi (Sets And Lists):
+ Document #'member*, #'remove*, #'delete* in this file. Document
+ #'memq, #'member, #'remq, #'remove, #'delq, #'delete in terms
of
+ the former functions.
+ Document #'subsetp, #'union, #'intersection, #'set-difference,
+ #'set-exclusive-or and their destructive analogues in this file.
+ * lispref/lists.texi (Association Lists):
+ Document #'assoc*, #'rassoc* in this file. Document #'assq,
+ #'assoc, #'rassq, #'rassoc in terms of the first two functions.
+ * lispref/objects.texi (Equality Predicates):
+ Document #'eql here, don't leave it to cl.texi.
+
2010-11-06 Aidan Kehoe <kehoea(a)parhasard.net>
* lispref/lists.texi (Rearrangement, Building Lists):
diff -r 31475de17064 -r f5a5501814f5 man/lispref/lists.texi
--- a/man/lispref/lists.texi Wed Feb 16 18:26:40 2011 +0000
+++ b/man/lispref/lists.texi Sat Feb 19 11:03:46 2011 +0000
＠＠ -1146,59 +1146,97 ＠＠
A list can represent an unordered mathematical set---simply consider a
value an element of a set if it appears in the list, and ignore the
-order of the list. To form the union of two sets, use ＠code{append} (as
-long as you don't mind having duplicate elements). Other useful
-functions for sets include ＠code{memq} and ＠code{delq}, and their
-＠code{equal} versions, ＠code{member} and ＠code{delete}.
+order of the list. XEmacs provides set operations inherited from Common
+Lisp.
-＠cindex CL note---lack ＠code{union}, ＠code{set}
-＠quotation
-＠b{Common Lisp note:} Common Lisp has functions ＠code{union} (which
-avoids duplicate elements) and ＠code{intersection} for set operations,
-but XEmacs Lisp does not have them. You can write them in Lisp if
-you wish.
-＠end quotation
+＠defun member* item list ＠t{&key :test :test-not :key}
+This function tests to see whether ＠var{item} is a member of ＠var{list},
+comparing with ＠code{eql}. If it is, ＠code{member*} returns the tail of
+＠var{list} starting with the first occurrence of ＠var{item}. Otherwise,
+it returns ＠code{nil}.
-＠defun memq object list
-＠cindex membership in a list
-This function tests to see whether ＠var{object} is a member of
-＠var{list}. If it is, ＠code{memq} returns a list starting with the
-first occurrence of ＠var{object}. Otherwise, it returns ＠code{nil}.
-The letter ＠samp{q} in ＠code{memq} says that it uses ＠code{eq} to
-compare ＠var{object} against the elements of the list. For example:
+This is equivalent to the Common Lisp ＠code{member} function, but that
+name was already taken in Emacs Lisp, whence the asterisk at the end of
+＠code{member*}.
+
+The ＠code{:test} keyword argument allows you to specify the test used to
+decide whether ＠var{item} is equivalent to a given element of
+＠var{list}. The function should return non-＠code{nil} if the items
+match, ＠code{nil} if they do not. The ＠code{:test-not} keyword is
+similar, but the meaning of ＠code{nil} and non-＠code{nil} results are
+reversed. The ＠code{:key} keyword allows you to examine a component of
+each object in ＠var{list}, rather than the object itself.
＠example
＠group
-(memq 'b '(a b c b a))
+(member* 'b '(a b c b a))
＠result{} (b c b a)
＠end group
＠group
-(memq '(2) '((1) (2))) ; ＠r{＠code{(2)} and ＠code{(2)} are not ＠code{eq}.}
+(member* '(2) '((1) (2))) ; ＠r{＠code{(2)} and ＠code{(2)} are not ＠code{eql}.}
＠result{} nil
+＠end group
+＠group
+(member* '(2) '((1) (2)) :test #'equal) ; ＠r{but they are ＠code{equal}.}
+ ＠result{} ((2))
+＠end group
+＠group
+(member* 3 '((1) (2) (3) (4)) :key 'car) ; ＠r{key not applied to ＠var{item}}
+ ＠result{} ((3) (4))
＠end group
＠end example
＠end defun
-＠defun delq object list
-＠cindex deletion of elements
-This function destructively removes all elements ＠code{eq} to
-＠var{object} from ＠var{list}. The letter ＠samp{q} in ＠code{delq} says
-that it uses ＠code{eq} to compare ＠var{object} against the elements of
-the list, like ＠code{memq}.
+＠defun memq item list
+This is equivalent to calling ＠code{(member* item list :test 'eq)}, but
+for historical reasons is more common in the XEmacs code base. Both
+expressions compile to the same byte-code.
＠end defun
-When ＠code{delq} deletes elements from the front of the list, it does so
-simply by advancing down the list and returning a sublist that starts
-after those elements:
+＠defun member item list
+This is equivalent to calling ＠code{(member* item list :test 'equal)}.
+＠end defun
+
+＠defun remove* item sequence ＠t{&key (test #'eql) (key #'identity) (start 0)
(end (length sequence)) from-end count test-not}
+＠cindex removal of elements
+
+This function removes all occurrences of ＠var{object} from
+＠var{sequence}, which can be a list, vector, or bit-vector.
+
+The ＠code{:test} keyword argument allows you to specify the test used to
+decide whether ＠var{item} is equivalent to a given element of
+＠var{sequence}. The function should return non-＠code{nil} if the items
+match, ＠code{nil} if they do not. The ＠code{:test-not} keyword is
+similar, but the meaning of ＠code{nil} and non-＠code{nil} results are
+reversed. The ＠code{:key} keyword allows you to examine a component of
+each object in ＠var{sequence}, rather than the object itself.
+
+The ＠code{:start} and ＠code{:end} keywords allow you to specify a
+zero-based subrange of ＠var{sequence} to operate on, ＠code{remove*} will
+call the test function on all items of ＠var{sequence} between the index
+specified by ＠code{:start}, inclusive, and ＠code{:end},
+exclusive. ＠code{:count} gives a maximum number of items to remove, and
+＠code{:from-end}, most useful in combination with ＠code{:count},
+specifies that the removal should start from the end of ＠var{sequence}.
+
+As with ＠code{member*}, this function is equivalent to the Common Lisp
+function of almost the same name (the Common Lisp function has no
+asterisk.)
+
+When ＠code{remove*} removes elements from the front of a list
+＠var{sequence}, it does so simply by advancing down the list and
+returning a sublist that starts after those elements:
＠example
＠group
-(delq 'a '(a b c)) ＠equiv{} (cdr '(a b c))
+(remove* 'a '(a b c)) ＠equiv{} (cdr '(a b c))
＠end group
＠end example
When an element to be deleted appears in the middle of the list,
-removing it involves changing the ＠sc{cdr}s (＠pxref{Setcdr}).
+removing it involves copying the list conses up to that point, and
+setting the tail of the copied list to the tail of the original list
+past that point.
＠example
＠group
＠＠ -1206,7 +1244,7 ＠＠
＠result{} (a b c (4))
＠end group
＠group
-(delq 'a sample-list)
+(remove* 'a sample-list)
＠result{} (b c (4))
＠end group
＠group
＠＠ -1214,7 +1252,55 ＠＠
＠result{} (a b c (4))
＠end group
＠group
-(delq 'c sample-list)
+(remove* 'c sample-list)
+ ＠result{} (a b (4))
+＠end group
+＠group
+sample-list
+ ＠result{} (a b c (4))
+＠end group
+＠end example
+
+Don't assume that a variable which formerly held the argument ＠var{list}
+now has fewer elements, or that it still holds the original list!
+Instead, save the result of ＠code{remove*} and use that. Most often we
+store the result back into the variable that held the original list:
+
+＠example
+(setq flowers (remove* 'rose flowers))
+＠end example
+
+In the following example, the ＠code{(4)} that ＠code{remove*} attempts to match
+and the ＠code{(4)} in the ＠code{sample-list} are not ＠code{eq}:
+
+＠example
+＠group
+(remove* '(4) sample-list)
+ ＠result{} (a b c (4))
+＠end group
+＠end example
+＠end defun
+
+＠defun remq item sequence
+This is equivalent to calling ＠code{(remove* item sequence :test #'eq)}.
+＠end defun
+
+＠defun remove item sequence
+This is equivalent to calling ＠code{(remove* item sequence :test #'equal)}.
+＠end defun
+
+＠defun delete* item sequence ＠t{&key (test #'eql) (key #'identity) (start 0)
(end (length sequence)) from-end count test-not}
+This is like ＠code{remove*}, but a list ＠var{sequence} is modified
+in-place (`destructively', in Lisp parlance). So some of the examples
+above change:
+
+＠example
+＠group
+(setq sample-list '(a b c (4)))
+ ＠result{} (a b c (4))
+＠end group
+＠group
+(delete* 'c sample-list)
＠result{} (a b (4))
＠end group
＠group
＠＠ -1222,78 +1308,80 ＠＠
＠result{} (a b (4))
＠end group
＠end example
-
-Note that ＠code{(delq 'c sample-list)} modifies ＠code{sample-list} to
-splice out the third element, but ＠code{(delq 'a sample-list)} does not
-splice anything---it just returns a shorter list. Don't assume that a
-variable which formerly held the argument ＠var{list} now has fewer
-elements, or that it still holds the original list! Instead, save the
-result of ＠code{delq} and use that. Most often we store the result back
-into the variable that held the original list:
-
-＠example
-(setq flowers (delq 'rose flowers))
-＠end example
-
-In the following example, the ＠code{(4)} that ＠code{delq} attempts to match
-and the ＠code{(4)} in the ＠code{sample-list} are not ＠code{eq}:
-
-＠example
-＠group
-(delq '(4) sample-list)
- ＠result{} (a c (4))
-＠end group
-＠end example
-
-The following two functions are like ＠code{memq} and ＠code{delq} but use
-＠code{equal} rather than ＠code{eq} to compare elements. They are new in
-Emacs 19.
-
-＠defun member object list
-The function ＠code{member} tests to see whether ＠var{object} is a member
-of ＠var{list}, comparing members with ＠var{object} using ＠code{equal}.
-If ＠var{object} is a member, ＠code{member} returns a list starting with
-its first occurrence in ＠var{list}. Otherwise, it returns ＠code{nil}.
-
-Compare this with ＠code{memq}:
-
-＠example
-＠group
-(member '(2) '((1) (2))) ; ＠r{＠code{(2)} and ＠code{(2)} are ＠code{equal}.}
- ＠result{} ((2))
-＠end group
-＠group
-(memq '(2) '((1) (2))) ; ＠r{＠code{(2)} and ＠code{(2)} are not ＠code{eq}.}
- ＠result{} nil
-＠end group
-＠group
-;; ＠r{Two strings with the same contents are ＠code{equal}.}
-(member "foo" '("foo" "bar"))
- ＠result{} ("foo" "bar")
-＠end group
-＠end example
＠end defun
-＠defun delete object list
-This function destructively removes all elements ＠code{equal} to
-＠var{object} from ＠var{list}. It is to ＠code{delq} as ＠code{member} is
-to ＠code{memq}: it uses ＠code{equal} to compare elements with
-＠var{object}, like ＠code{member}; when it finds an element that matches,
-it removes the element just as ＠code{delq} would. For example:
-
-＠example
-＠group
-(delete '(2) '((2) (1) (2)))
- ＠result{} '((1))
-＠end group
-＠end example
+＠defun delq item sequence
+This is equivalent to calling ＠code{(delete* item sequence :test #'eq)}.
＠end defun
-＠quotation
-＠b{Common Lisp note:} The functions ＠code{member} and ＠code{delete} in
-XEmacs Lisp are derived from Maclisp, not Common Lisp. The Common
-Lisp versions do not use ＠code{equal} to compare elements.
-＠end quotation
+＠defun delete item list
+This is equivalent to calling ＠code{(delete* item sequence :test #'equal)}.
+＠end defun
+
+＠defun subsetp list1 list2 ＠t{&key :test :test-not :key}
+This function returns non-＠code{nil} if every item in ＠var{list1} is
+present in ＠var{list2}.
+＠end defun
+
+＠defun union list1 list2 ＠t{&key :test :test-not :key :stable}
+This function calculates the union of two lists, returning a list
+containing all those items that appear in either list. It doesn't
+guarantee that duplicates in ＠var{list1} or ＠var{list2} will be
+eliminated; see ＠code{remove-duplicates} if this is important to you.
+
+A non-nil value for the ＠code{:stable} keyword, not specified by Common
+Lisp, means return the items in the order they appear in ＠var{list1},
+followed by the remaining items in the order they appear in ＠var{list2}.
+The other keywords are as in ＠code{member*}.
+
+＠code{union} does not modify ＠var{list1} or ＠var{list2}.
+＠end defun
+
+＠defun intersection list1 list2 ＠t{&key :test :test-not :key :stable}
+This function calculates the intersection of two lists, returning a list
+containing all those items that appear in both lists. It doesn't
+guarantee that duplicates in ＠var{list1} or ＠var{list2} will be
+eliminated; see ＠code{remove-duplicates} if this is important to
+you. ＠code{intersection} does not modify either list.
+
+A non-nil value for the ＠code{:stable} keyword, not specified by Common
+Lisp, means return the items in the order they appear in ＠var{list1}.
+The other keywords are as in ＠code{member*}.
+＠end defun
+
+＠defun set-difference list1 list2 ＠t{&key :test :test-not :key :stable}
+This function returns those items that are in ＠var{list1} but not in
+＠var{list2}. It does not modify either list.
+
+A non-nil value for the ＠code{:stable} keyword, not specified by Common
+Lisp, means return the items in the order they appear in ＠var{list1}.
+The other keywords are as in ＠code{member*}.
+＠end defun
+
+＠defun set-exclusive-or list1 list2 ＠t{&key :test :test-not :key :stable}
+This function returns those items that are in ＠var{list1} but not in
+＠var{list2}, together with those in ＠var{list2} but not in ＠var{list1}.
+It does not modify either list.
+
+A non-nil value for the ＠code{:stable} keyword, not specified by Common
+Lisp, means return the items in the order they appear in ＠var{list1},
+followed by the remaining items in the order they appear in ＠var{list2}.
+The other keywords are as in ＠code{member*}.
+＠end defun
+
+The following functions are equivalent to the previous four functions,
+but with two important differences; they do not accept the
+＠code{:stable} keyword, and they modify one or both list arguments in
+the same way ＠code{delete*} does.
+
+＠defun nintersection list1 list2 ＠t{&key :test :test-not :key}
+＠end defun
+＠defun nset-difference list1 list2 ＠t{&key :test :test-not :key}
+＠end defun
+＠defun nset-exclusive-or list1 list2 ＠t{&key :test :test-not :key}
+＠end defun
+＠defun nunion list1 list2 ＠t{&key :test :test-not :key}
+＠end defun
See also the function ＠code{add-to-list}, in ＠ref{Setting Variables},
for another way to add an element to a list stored in a variable.
＠＠ -1370,21 +1458,21 ＠＠
each key can occur only once. ＠xref{Property Lists}, for a comparison
of property lists and association lists.
-＠defun assoc key alist
+＠defun assoc* key alist ＠t{&key :test :test-not :key}
This function returns the first association for ＠var{key} in
＠var{alist}. It compares ＠var{key} against the alist elements using
-＠code{equal} (＠pxref{Equality Predicates}). It returns ＠code{nil} if no
-association in ＠var{alist} has a ＠sc{car} ＠code{equal} to ＠var{key}.
-For example:
+＠code{eql} (＠pxref{Equality Predicates}), or the test specified with the
+＠code{:test} keyword. It returns ＠code{nil} if no association in
+＠var{alist} has a ＠sc{car} ＠code{equal} to ＠var{key}. For example:
＠smallexample
(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
＠result{} ((pine . cones) (oak . acorns) (maple . seeds))
-(assoc 'oak trees)
+(assoc* 'oak trees)
＠result{} (oak . acorns)
-(cdr (assoc 'oak trees))
+(cdr (assoc* 'oak trees))
＠result{} acorns
-(assoc 'birch trees)
+(assoc* 'birch trees)
＠result{} nil
＠end smallexample
＠＠ -1396,31 +1484,36 ＠＠
(3 "Pitch Pine")
(5 "White Pine")))
-(cdr (assoc 3 needles-per-cluster))
+(cdr (assoc* 3 needles-per-cluster))
＠result{} ("Pitch Pine")
-(cdr (assoc 2 needles-per-cluster))
+(cdr (assoc* 2 needles-per-cluster))
＠result{} ("Austrian Pine" "Red Pine")
＠end smallexample
+
+The ＠code{:test} keyword argument allows you to specify the test used to
+decide whether ＠var{key} is equivalent to a given element of
+＠var{alist}. The function should return non-＠code{nil} if the items
+match, ＠code{nil} if they do not. The ＠code{:test-not} keyword is
+similar, but the meaning of ＠code{nil} and non-＠code{nil} results are
+reversed. The ＠code{:key} keyword allows you to examine a component of
+each ＠sc{car} in ＠var{alist}, rather than the ＠sc{car} itself.
＠end defun
-＠defun rassoc value alist
+＠defun rassoc* value alist ＠t{&key :test :test-not :key}
This function returns the first association with value ＠var{value} in
＠var{alist}. It returns ＠code{nil} if no association in ＠var{alist} has
-a ＠sc{cdr} ＠code{equal} to ＠var{value}.
+a ＠sc{cdr} ＠code{eql} to ＠var{value}.
-＠code{rassoc} is like ＠code{assoc} except that it compares the ＠sc{cdr} of
+＠code{rassoc*} is like ＠code{assoc*} except that it compares the ＠sc{cdr} of
each ＠var{alist} association instead of the ＠sc{car}. You can think of
-this as ``reverse ＠code{assoc}'', finding the key for a given value.
+this as ``reverse ＠code{assoc*}'', finding the key for a given value.
+
+The keywords work similarly to ＠code{assoc*}.
＠end defun
＠defun assq key alist
-This function is like ＠code{assoc} in that it returns the first
-association for ＠var{key} in ＠var{alist}, but it makes the comparison
-using ＠code{eq} instead of ＠code{equal}. ＠code{assq} returns ＠code{nil}
-if no association in ＠var{alist} has a ＠sc{car} ＠code{eq} to ＠var{key}.
-This function is used more often than ＠code{assoc}, since ＠code{eq} is
-faster than ＠code{equal} and most alists use symbols as keys.
-＠xref{Equality Predicates}.
+This is equivalent to calling ＠code{(assoc* key alist :test 'eq)}, and
+compiles to the same byte code.
＠smallexample
(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
＠＠ -1429,8 +1522,8 ＠＠
＠result{} (pine . cones)
＠end smallexample
-On the other hand, ＠code{assq} is not usually useful in alists where the
-keys may not be symbols:
+＠code{assq} is not usually useful in alists where the keys may not be
+symbols:
＠smallexample
(setq leaves
＠＠ -1445,15 +1538,8 ＠＠
＠end defun
＠defun rassq value alist
-This function returns the first association with value ＠var{value} in
-＠var{alist}. It returns ＠code{nil} if no association in ＠var{alist} has
-a ＠sc{cdr} ＠code{eq} to ＠var{value}.
-
-＠code{rassq} is like ＠code{assq} except that it compares the ＠sc{cdr} of
-each ＠var{alist} association instead of the ＠sc{car}. You can think of
-this as ``reverse ＠code{assq}'', finding the key for a given value.
-
-For example:
+This is equivalent to calling ＠code{(rassoc* value alist :test 'eq)}, and
+compiles to the same byte code. For example:
＠smallexample
(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
diff -r 31475de17064 -r f5a5501814f5 man/lispref/objects.texi
--- a/man/lispref/objects.texi Wed Feb 16 18:26:40 2011 +0000
+++ b/man/lispref/objects.texi Sat Feb 19 11:03:46 2011 +0000
＠＠ -2237,7 +2237,7 ＠＠
＠section Equality Predicates
＠cindex equality
- Here we describe two functions that test for equality between any two
+ Here we describe functions that test for equality between any two
objects. Other functions test equality between objects of specific
types, e.g., strings. For these predicates, see the appropriate chapter
describing the data type.
＠＠ -2339,6 +2339,31 ＠＠
＠result{} t ; ＠r{Eek, we've been infected.}
(eq ?A 65)
＠result{} nil ; ＠r{We are still healthy.}
+＠end group
+＠end example
+＠end defun
+
+＠defun eql object1 object2
+
+This function returns ＠code{t} if the two arguments are the same object,
+as with ＠code{eq}. In addition, it returns ＠code{t} if ＠var{object1}
+and ＠var{object2} are numeric objects of the same type and with equal
+values. Otherwise it returns ＠code{nil}. ＠code{eql} is the default
+test for hash tables, and for many sequence-oriented functions inherited
+from Common Lisp.
+
+＠example
+＠group
+(eql 1 1)
+ ＠result{} t
+(eql 1 1.0) ; different types
+ ＠result{} nil
+(eq (+ 0.0 pi) pi)
+ ＠result{} nil ; in some contexts can be t, but don't rely on this!
+(eql (+ 0.0 pi) pi)
+ ＠result{} t ; this is more reliable.
+(position (+ 0 pi) (list 0 1 2 pi 4))
+ ＠result{} 3 ; function's test defaults to eql
＠end group
＠end example
＠end defun
diff -r 31475de17064 -r f5a5501814f5 src/ChangeLog
--- a/src/ChangeLog Wed Feb 16 18:26:40 2011 +0000
+++ b/src/ChangeLog Sat Feb 19 11:03:46 2011 +0000
＠＠ -1,3 +1,9 ＠＠
+2011-02-19 Aidan Kehoe <kehoea(a)parhasard.net>
+
+ * fns.c (Fset_exclusive_or):
+ This function accepts the :stable keyword too, document this in
+ its arglist.
+
2011-02-16 Aidan Kehoe <kehoea(a)parhasard.net>
* xemacs.def.in.in:
diff -r 31475de17064 -r f5a5501814f5 src/fns.c
--- a/src/fns.c Wed Feb 16 18:26:40 2011 +0000
+++ b/src/fns.c Sat Feb 19 11:03:46 2011 +0000
＠＠ -10876,7 +10876,7 ＠＠
return the items in the order they appear in LIST1, followed by the
remaining items in the order they appear in LIST2.
-arguments: (LIST1 LIST2 &key (TEST #'eql) (KEY #'identity) TEST-NOT)
+arguments: (LIST1 LIST2 &key (TEST #'eql) (KEY #'identity) TEST-NOT STABLE)
*/
(int nargs, Lisp_Object *args))
{
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