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<head>
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<title>R</title>
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</head>
<body>

<h1>R</h1>

<dl>

<dt><a name="*Run"><code>*Run</code></a>
<dd>This global variable can hold a list of <code>prg</code> expressions which
are used during <code><a href="refK.html#key">key</a></code>, <code><a
href="refS.html#sync">sync</a></code>, <code><a
href="refW.html#wait">wait</a></code> and <code><a
href="refL.html#listen">listen</a></code>. The first element of each expression
must either be a positive number (thus denoting a file descriptor to wait for)
or a negative number (denoting a timeout value in milliseconds (in that case
another number must follow to hold the remaining time)). A <code>select</code>
system call is performed with these values, and the corresponding
<code>prg</code> body is executed when input data are available or when a
timeout occurred. See also <code><a href="refT.html#task">task</a></code>.

<pre><code>
: (de *Run (-2000 0 (println '2sec)))     # Install 2-sec-timer
-> *Run
: 2sec                                    # Prints "2sec" every 2 seconds
2sec
2sec
                                          # (Ctrl-D) Exit
$
</code></pre>

<dt><a name="+Ref"><code>+Ref</code></a>
<dd>Prefix class for maintaining non-unique indexes to <code><a
href="refR.html#+relation">+relation</a></code>s, a subclass of <code><a
href="refI.html#+index">+index</a></code>. Accepts an optional argument for a
<code><a href="refH.html#+Hook">+Hook</a></code> attribute. See also <code><a
href="ref.html#dbase">Database</a></code>.

<pre><code>
(rel tel (+Fold +Ref +String))  # Phone number with folded, non-unique index
</code></pre>

<dt><a name="+Ref2"><code>+Ref2</code></a>
<dd>Prefix class for maintaining a secondary ("backing") index to <code><a
href="refR.html#+relation">+relation</a></code>s. Can only be used as a prefix
class to <code><a href="refK.html#+Key">+Key</a></code> or <code><a
href="refR.html#+Ref">+Ref</a></code>. It maintains an index in the current
(sub)class, in addition to that in one of the superclasses, to allow
(sub)class-specific queries. See also <code><a
href="ref.html#dbase">Database</a></code>.

<pre><code>
(class +Ord +Entity)             # Order class
(rel nr (+Need +Key +Number))    # Order number
...
(class +EuOrd +Ord)              # EU-specific order subclass
(rel nr (+Ref2 +Key +Number))    # Order number with backing index
</code></pre>

<dt><a name="+relation"><code>+relation</code></a>
<dd>Abstract base class of all database releations. Relation objects are usually
defined with <code><a href="refR.html#rel">rel</a></code>. The class hierarchy
includes the classes <code><a href="refA.html#+Any">+Any</a></code>, <code><a
href="refB.html#+Bag">+Bag</a></code>, <code><a
href="refB.html#+Bool">+Bool</a></code>, <code><a
href="refN.html#+Number">+Number</a></code>, <code><a
href="refD.html#+Date">+Date</a></code>, <code><a
href="refT.html#+Time">+Time</a></code>, <code><a
href="refS.html#+Symbol">+Symbol</a></code>, <code><a
href="refS.html#+String">+String</a></code>, <code><a
href="refL.html#+Link">+Link</a></code>, <code><a
href="refJ.html#+Joint">+Joint</a></code> and <code><a
href="refB.html#+Blob">+Blob</a></code>, and the prefix classes <code><a
href="refH.html#+Hook">+Hook</a></code>, <code><a
href="refI.html#+index">+index</a></code>, <code><a
href="refK.html#+Key">+Key</a></code>, <code><a
href="refR.html#+Ref">+Ref</a></code>, <code><a
href="refR.html#+Ref2">+Ref2</a></code>, <code><a
href="refI.html#+Idx">+Idx</a></code>, <code><a
href="refS.html#+Sn">+Sn</a></code>, <code><a
href="refF.html#+Fold">+Fold</a></code>, <code><a
href="refA.html#+Aux">+Aux</a></code>, <code><a
href="refU.html#+UB">+UB</a></code>, <code><a
href="refD.html#+Dep">+Dep</a></code>, <code><a
href="refL.html#+List">+List</a></code>, <code><a
href="refN.html#+Need">+Need</a></code>, <code><a
href="refM.html#+Mis">+Mis</a></code> and <code><a
href="refA.html#+Alt">+Alt</a></code>. See also <code><a
href="ref.html#dbase">Database</a></code> and <code><a
href="refE.html#+Entity">+Entity</a></code>.

<p><a name="relationMesssages">Messages</a> to relation objects include

<pre><code>
mis> (Val Obj)       # Return error if mismatching type or value
has> (Val X)         # Check if the value is present
put> (Obj Old New)   # Put new value
rel> (Obj Old New)   # Maintain relational strutures
lose> (Obj Val)      # Delete relational structures
keep> (Obj Val)      # Restore deleted relational structures
zap> (Obj Val)       # Clean up relational structures
</code></pre>

<dt><a name="rand"><code>(rand ['cnt1 'cnt2] | ['T]) -> cnt | flg</code></a>
<dd>Returns a pseudo random number in the range cnt1 .. cnt2 (or -2147483648 ..
+2147483647 if no arguments are given). If the argument is <code>T</code>, a
boolean value <code>flg</code> is returned. See also <code><a
href="refS.html#seed">seed</a></code>.

<pre><code>
: (rand 3 9)
-> 3
: (rand 3 9)
-> 7
</code></pre>

<dt><a name="range"><code>(range 'num1 'num2 ['num3]) -> lst</code></a>
<dd>Produces a list of numbers in the range <code>num1</code> through
<code>num2</code>. When <code>num3</code> is non-<code>NIL</code>), it is used
to increment <code>num1</code> (if it is smaller than <code>num2</code>) or to
decrement <code>num1</code> (if it is greater than <code>num2</code>). See also
<code><a href="refN.html#need">need</a></code>.

<pre><code>
: (range 1 6)
-> (1 2 3 4 5 6)
: (range 6 1)
-> (6 5 4 3 2 1)
: (range -3 3)
-> (-3 -2 -1 0 1 2 3)
: (range 3 -3 2)
-> (3 1 -1 -3)
</code></pre>

<dt><a name="range/3"><code>range/3</code></a>
<dd><a href="ref.html#pilog">Pilog</a> predicate that succeeds if the first
argument is in the range of the result of applying the <code><a
href="refG.html#get">get</a></code> algorithm to the following arguments.
Typically used as filter predicate in <code><a
href="refS.html#select/3">select/3</a></code> database queries. See also
<code><a href="ref.html#cmp">Comparing</a></code>, <code><a
href="refI.html#isa/2">isa/2</a></code>, <code><a
href="refS.html#same/3">same/3</a></code>, <code><a
href="refB.html#bool/3">bool/3</a></code>, <code><a
href="refH.html#head/3">head/3</a></code>, <code><a
href="refF.html#fold/3">fold/3</a></code>, <code><a
href="refP.html#part/3">part/3</a></code> and <code><a
href="refT.html#tolr/3">tolr/3</a></code>.

<pre><code>
: (?
   @Nr (1 . 5)  # Numbers between 1 and 5
   @Nm "part"
   (select (@Item)
      ((nr +Item @Nr) (nm +Item @Nm))
      (range @Nr @Item nr)
      (part @Nm @Item nm) ) )
 @Nr=(1 . 5) @Nm="part" @Item={3-1}                                              @Nr=(1 . 5) @Nm="part" @Item={3-2}
-> NIL
</code></pre>

<dt><a name="rank"><code>(rank 'any 'lst ['flg]) -> lst</code></a>
<dd>Searches a ranking list. <code>lst</code> should be sorted. Returns the
element from <code>lst</code> with a maximal CAR less or equal to
<code>any</code> (if <code>flg</code> is <code>NIL</code>), or with a minimal
CAR greater or equal to <code>any</code> (if <code>flg</code> is
non-<code>NIL</code>), or <code>NIL</code> if no match is found. See also
<code><a href="refA.html#assoc">assoc</a></code> and <a
href="ref.html#cmp">Comparing</a>.

<pre><code>
: (rank 0 '((1 . a) (100 . b) (1000 . c)))
-> NIL
: (rank 50 '((1 . a) (100 . b) (1000 . c)))
-> (1 . a)
: (rank 100 '((1 . a) (100 . b) (1000 . c)))
-> (100 . b)
: (rank 300 '((1 . a) (100 . b) (1000 . c)))
-> (100 . b)
: (rank 9999 '((1 . a) (100 . b) (1000 . c)))
-> (1000 . c)
: (rank 50 '((1000 . a) (100 . b) (1 . c)) T)
-> (100 . b)
</code></pre>

<dt><a name="raw"><code>(raw ['flg]) -> flg</code></a>
<dd>Console mode control function. When called without arguments, it returns the
current console mode (<code>NIL</code> for "cooked mode"). Otherwise, the
console is set to the new state. See also <code><a
href="refK.html#key">key</a></code>.

<pre><code>
$ pil
: (raw)
-> NIL
$ pil +
: (raw)
-> T
</code></pre>

<dt><a name="rc"><code>(rc 'sym 'any1 ['any2]) -> any</code></a>
<dd>Fetches a value from a resource file <code>sym</code>, or stores a value
<code>any2</code> in that file, using a key <code>any1</code>. All values are
stored in a list in the file, using <code><a
href="refA.html#assoc">assoc</a></code>. During the whole operation, the file is
exclusively locked with <code><a href="refC.html#ctl">ctl</a></code>.

<pre><code>
: (info "a.rc")               # File exists?
-> NIL                        # No
: (rc "a.rc" 'a 1)            # Store 1 for 'a'
-> 1
: (rc "a.rc" 'b (2 3 4))      # Store (2 3 4) for 'b'
-> (2 3 4)
: (rc "a.rc" 'c 'b)           # Store 'b' for 'c'
-> b
: (info "a.rc")               # Check file
-> (28 733124 . 61673)
: (in "a.rc" (echo))          # Display it
((c . b) (b 2 3 4) (a . 1))
-> T
: (rc "a.rc" 'c)              # Fetch value for 'c'
-> b
: (rc "a.rc" @)               # Fetch value for 'b'
-> (2 3 4)
</code></pre>

<dt><a name="rd"><code>(rd ['sym]) -> any</code></a>
<dt><code>(rd 'cnt) -> num | NIL</code>
<dd>Binary read: Reads one item from the current input channel in encoded binary
format. When called with a <code>cnt</code> argument (second form), that number
of raw bytes (in big endian format if <code>cnt</code> is positive, otherwise
little endian) is read as a single number. Upon end of file, if the
<code>sym</code> argument is given, it is returned, otherwise <code>NIL</code>.
See also <code><a href="refP.html#pr">pr</a></code>, <code><a
href="refT.html#tell">tell</a></code>, <code><a
href="refH.html#hear">hear</a></code> and <code><a
href="refW.html#wr">wr</a></code>.

<pre><code>
: (out "x" (pr 'abc "EOF" 123 "def"))
-> "def"
: (in "x" (rd))
-> abc
: (in "x"
   (make
      (use X
         (until (== "EOF" (setq X (rd "EOF")))  # '==' detects end of file
            (link X) ) ) ) )
-> (abc "EOF" 123 "def")  # as opposed to reading a symbol "EOF"

: (in "/dev/urandom" (rd 20))
-> 396737673456823753584720194864200246115286686486
</code></pre>

<dt><a name="read"><code>(read ['sym1 ['sym2]]) -> any</code></a>
<dd>Reads one item from the current input channel. <code>NIL</code> is returned
upon end of file. When called without arguments, an arbitrary Lisp expression is
read. Otherwise, a token (a number, or an internal or transient symbol) is read.
In that case, <code>sym1</code> specifies which set of characters to accept for
continuous symbol names (in addition to the standard alphanumerical characters),
and <code>sym2</code> an optional comment character. See also <code><a
href="refA.html#any">any</a></code>, <code><a
href="refS.html#str">str</a></code>, <code><a
href="refS.html#skip">skip</a></code> and <code><a
href="refE.html#eof">eof</a></code>.

<pre><code>
: (list (read) (read) (read))    # Read three things from console
123                              # a number
abcd                             # a symbol
(def                             # and a list
ghi
jkl
)
-> (123 abcd (def ghi jkl))
: (make (while (read "_" "#") (link @)))
abc = def_ghi("xyz"+-123) # Comment
NIL
-> (abc "=" def_ghi "(" "xyz" "+" "-" 123 ")")
</code></pre>

<dt><a name="recur"><code>(recur fun) -> any</code></a>
<dt><a name="recurse"><code>(recurse ..) -> any</code></a>
<dd>Implements anonymous recursion, by defining the function
<code>recurse</code> on the fly. During the execution of <code>fun</code>, the
symbol <code>recurse</code> is bound to the function definition
<code>fun</code>. See also <code><a href="refL.html#let">let</a></code> and
<code><a href="ref.html#lambda">lambda</a></code>.

<pre><code>
: (de fibonacci (N)
   (when (lt0 N)
      (quit "Bad fibonacci" N) )
   (recur (N)
      (if (> 2 N)
         1
         (+
            (recurse (dec N))
            (recurse (- N 2)) ) ) ) )
-> fibonacci
: (fibonacci 22)
-> 28657
: (fibonacci -7)
-7 -- Bad fibonacci
</code></pre>

<dt><a name="redef"><code>(redef sym . fun) -> sym</code></a>
<dd>Redefines <code>sym</code> in terms of itself. The current definition is
saved in a new symbol, which is substituted for each occurrence of
<code>sym</code> in <code>fun</code>, and which is also returned. See also
<code><a href="refD.html#de">de</a></code>, <code><a
href="refU.html#undef">undef</a></code>, <code><a
href="refD.html#daemon">daemon</a></code> and <code><a
href="refP.html#patch">patch</a></code>.

<pre><code>
: (de hello () (prinl "Hello world!"))
-> hello
: (pp 'hello)
(de hello NIL
   (prinl "Hello world!") )
-> hello

: (redef hello (A B)
   (println 'Before A)
   (prog1 (hello) (println 'After B)) )
-> "hello"
: (pp 'hello)
(de hello (A B)
   (println 'Before A)
   (prog1 ("hello") (println 'After B)) )
-> hello
: (hello 1 2)
Before 1
Hello world!
After 2
-> "Hello world!"

: (redef * @
   (msg (rest))
   (pass *) )
-> "*"
: (* 1 2 3)
(1 2 3)
-> 6

: (redef + @
   (pass (ifn (num? (next)) pack +) (arg)) )
-> "+"
: (+ 1 2 3)
-> 6
: (+ "a" 'b '(c d e))
-> "abcde"

</code></pre>

<dt><a name="rel"><code>(rel var lst [any ..]) -> any</code></a>
<dd>Defines a relation for <code>var</code> in the current class <code><a
href="refC.html#*Class">*Class</a></code>, using <code>lst</code> as the list of
classes for that relation, and possibly additional arguments <code>any</code>
for its initialization. See also <a href="ref.html#dbase">Database</a>, <a
href="refC.html#class">class</a>, <a href="refE.html#extend">extend</a>, <a
href="refD.html#dm">dm</a> and <a href="refV.html#var">var</a>.

<pre><code>
(class +Person +Entity)
(rel nm  (+List +Ref +String))            # Names
(rel tel (+Ref +String))                  # Telephone
(rel adr (+Joint) prs (+Address))         # Address

(class +Address +Entity)
(rel cit (+Need +Hook +Link) (+City))     # City
(rel str (+List +Ref +String) cit)        # Street
(rel prs (+List +Joint) adr (+Person))    # Inhabitants

(class +City +Entity)
(rel nm  (+List +Ref +String))            # Zip / Names
</code></pre>

<dt><a name="release"><code>(release 'sym) -> NIL</code></a>
<dd>Releases the mutex represented by the file 'sym'. This is the reverse
operation of <code><a href="refA.html#acquire">acquire</a></code>.

<pre><code>
: (release "sema1")
-> NIL
</code></pre>

<dt><a name="remote/2"><code>remote/2</code></a>
<dd><a href="ref.html#pilog">Pilog</a> predicate for remote database queries. It
takes a list and an arbitrary number of clauses. The list should contain a Pilog
variable for the result in the CAR, and a list of resources in the CDR. The
clauses will be evaluated on remote machines according to these resources. Each
resource must be a cons pair of two functions, an "out" function in the CAR, and
an "in" function in the CDR. See also <code><a
href="refE.html#*Ext">*Ext</a></code>, <code><a
href="refS.html#select/3">select/3</a></code> and <code><a
href="refD.html#db/3">db/3</a></code>.

<pre><code>
(setq *Ext           # Set up external offsets
   (mapcar
      '((@Host @Ext)
         (cons @Ext
            (curry (@Host @Ext (Sock)) (Obj)
               (when (or Sock (setq Sock (connect @Host 4040)))
                  (ext @Ext
                     (out Sock (pr (cons 'qsym Obj)))
                     (prog1 (in Sock (rd))
                        (unless @
                           (close Sock)
                           (off Sock) ) ) ) ) ) ) )
      '("localhost")
      '(20) ) )

(de rsrc ()  # Simple resource handler, ignoring errors or EOFs
   (extract
      '((@Ext Host)
         (let? @Sock (connect Host 4040)
            (cons
               (curry (@Ext @Sock) (X)  # out
                  (ext @Ext (out @Sock (pr X))) )
               (curry (@Ext @Sock) ()  # in
                  (ext @Ext (in @Sock (rd))) ) ) ) )
      '(20)
      '("localhost") ) )

: (?
   @Nr (1 . 3)
   @Sup 2
   @Rsrc (rsrc)
   (remote (@Item . @Rsrc)
      (db nr +Item @Nr @Item)
      (val @Sup @Item sup nr) )
   (show @Item) )
{L-2} (+Item)
   pr 1250
   inv 100
   sup {K-2}
   nm Spare Part
   nr 2
 @Nr=(1 . 3) @Sup=2 @Rsrc=((((X) (ext 20 (out 16 (pr X)))) NIL (ext 20 (in 16 (rd))))) @Item={L-2}
-> NIL
</code></pre>

<dt><a name="remove"><code>(remove 'cnt 'lst) -> lst</code></a>
<dd>Removes the element at position <code>cnt</code> from <code>lst</code>. This
is a non-destructive operation. See also <code><a
href="refI.html#insert">insert</a></code>, <code><a
href="refP.html#place">place</a></code>, <code><a
href="refA.html#append">append</a></code>, <code><a
href="refD.html#delete">delete</a></code> and <code><a
href="refR.html#replace">replace</a></code>.

<pre><code>
: (remove 3 '(a b c d e))
-> (a b d e)
: (remove 1 '(a b c d e))
-> (b c d e)
: (remove 9 '(a b c d e))
-> (a b c d e)
</code></pre>

<dt><a name="repeat"><code>(repeat) -> lst</code></a>
<dd>Makes the current <a href="ref.html#pilog">Pilog</a> definition "tail
recursive", by closing the previously defined rules in the definition's T
property to a circular list. See also <code><a
href="refR.html#repeat/0">repeat/0</a></code> and <code><a
href="refB.html#be">be</a></code>.

<pre><code>
(be a (1))     # Define three facts
(be a (2))
(be a (3))
(repeat)       # Unlimited supply

: (? (a @N))
 @N=1
 @N=2
 @N=3
 @N=1
 @N=2
 @N=3.         # Stop
-> NIL
</code></pre>

<dt><a name="repeat/0"><code>repeat/0</code></a>
<dd><a href="ref.html#pilog">Pilog</a> predicate that always succeeds, also on
backtracking. See also <code><a href="refR.html#repeat">repeat</a></code> and
<code><a href="refT.html#true/0">true/0</a></code>.

<pre><code>
: (be integer (@I)   # Generate unlimited supply of integers
   (@C box 0)        # Init to zero
   (repeat)          # Repeat from here
   (@I inc (-> @C)) )
-> integer

: (? (integer @X))
 @X=1
 @X=2
 @X=3
 @X=4.               # Stop
-> NIL
</code></pre>

<dt><a name="replace"><code>(replace 'lst 'any1 'any2 ..) -> lst</code></a>
<dd>Replaces in <code>lst</code> all occurrences of <code>any1</code> with
<code>any2</code>. For optional additional argument pairs, this process is
repeated. This is a non-destructive operation. See also <code><a
href="refA.html#append">append</a></code>, <code><a
href="refD.html#delete">delete</a></code>, <code><a
href="refI.html#insert">insert</a></code>, <code><a
href="refR.html#remove">remove</a></code> and <code><a
href="refP.html#place">place</a></code>.

<pre><code>
: (replace '(a b b a) 'a 'A)
-> (A b b A)
: (replace '(a b b a) 'b 'B)
-> (a B B a)
: (replace '(a b b a) 'a 'B 'b 'A)
-> (B A A B)
</code></pre>

<dt><a name="request"><code>(request 'typ 'var ['hook] 'val ..) -> obj</code></a>
<dd>Returns a database object. If a matching object cannot be found (using
<code><a href="refD.html#db">db</a></code>), a new object of the given type is
created (using <code><a href="refN.html#new">new</a></code>). See also <code><a
href="refO.html#obj">obj</a></code>.

<pre><code>
: (request '(+Item) 'nr 2)
-> {3-2}
</code></pre>

<dt><a name="rest"><code>(rest) -> lst</code></a>
<dd>Can only be used inside functions with a variable number of arguments (with
<code>@</code>). Returns the list of all remaining arguments from the internal
list. See also <code><a href="refA.html#args">args</a></code>, <code><a
href="refN.html#next">next</a></code>, <code><a
href="refA.html#arg">arg</a></code> and <code><a
href="refP.html#pass">pass</a></code>.

<pre><code>
: (de foo @ (println (rest)))
-> foo
: (foo 1 2 3)
(1 2 3)
-> (1 2 3)
</code></pre>

<dt><a name="retract">(retract) -> lst<code></code></a>
<dd>Removes a <a href="ref.html#pilog">Pilog</a> fact or rule. See also <code><a
href="refB.html#be">be</a></code>, <code><a
href="refC.html#clause">clause</a></code>, <code><a
href="refA.html#asserta">asserta</a></code> and <code><a
href="refA.html#assertz">assertz</a></code>.

<pre><code>
: (be a (1))
-> a
: (be a (2))
-> a
: (be a (3))
-> a

: (retract '(a (2)))
-> (((1)) ((3)))

:  (? (a @N))
 @N=1
 @N=3
-> NIL
</code></pre>

<dt><a name="retract/1"><code>retract/1</code></a>
<dd><a href="ref.html#pilog">Pilog</a> predicate that removes a fact or rule.
See also <code><a href="refR.html#retract">retract</a></code>, <code><a
href="refA.html#asserta/1">asserta/1</a></code> and <code><a
href="refA.html#assertz/1">assertz/1</a></code>.

<pre><code>
: (be a (1))
-> a
: (be a (2))
-> a
: (be a (3))
-> a

: (? (retract (a 2)))
-> T
: (rules 'a)
1 (be a (1))
2 (be a (3))
-> a
</code></pre>

<dt><a name="reverse"><code>(reverse 'lst) -> lst</code></a>
<dd>Returns a reversed copy of <code>lst</code>. See also <code><a
href="refF.html#flip">flip</a></code>.

<pre><code>
: (reverse (1 2 3 4))
-> (4 3 2 1)
</code></pre>

<dt><a name="rewind"><code>(rewind) -> flg</code></a>
<dd>Sets the file position indicator for the current output stream to the
beginning of the file, and truncates the file length to zero. Returns
<code>T</code> when successful. See also <code><a
href="refF.html#flush">flush</a></code>.

<pre><code>
: (out "a" (prinl "Hello world"))
-> "Hello world"
: (in "a" (echo))
Hello world
-> T
: (info "a")
-> (12 733216 . 53888)
: (out "a" (rewind))
-> T
: (info "a")
-> (0 733216 . 53922)
</code></pre>

<dt><a name="rollback"><code>(rollback) -> T</code></a>
<dd>Cancels a transaction, by discarding all modifications of external symbols.
See also <code><a href="refC.html#commit">commit</a></code>.

<pre><code>
: (pool "db")
-> T
# .. Modify external objects ..
: (rollback)            # Rollback
-> T
</code></pre>

<dt><a name="root"><code>(root 'tree) -> (num . sym)</code></a>
<dd>Returns the root of a database index tree, with the number of entries in
<code>num</code>, and the base node in <code>sym</code>. See also <code><a
href="refT.html#tree">tree</a></code>.

<pre><code>
: (root (tree 'nr '+Item))
-> (7 . {7-1})
</code></pre>

<dt><a name="rot"><code>(rot 'lst ['cnt]) -> lst</code></a>
<dd>Rotate: The contents of the cells of <code>lst</code> are (destructively)
shifted right, and the value from the last cell is stored in the first cell.
Without the optional <code>cnt</code> argument, the whole list is rotated,
otherwise only the first <code>cnt</code> elements. See also <code><a
href="refF.html#flip">flip</a></code> .

<pre><code>
: (rot (1 2 3 4))             # Rotate all four elements
-> (4 1 2 3)
: (rot (1 2 3 4 5 6) 3)       # Rotate only the first three elements
-> (3 1 2 4 5 6)
</code></pre>

<dt><a name="round"><code>(round 'num1 'num2) -> sym</code></a>
<dd>Formats a number <code>num1</code> with <code>num2</code> decimal places,
according to the current scale <code><a href="refS.html#*Scl">*Scl</a></code>.
<code>num2</code> defaults to 3. See also <a href="ref.html#num-io">Numbers</a>
and <code><a href="refF.html#format">format</a></code>.

<pre><code>
: (scl 4)               # Set scale to 4
-> 4
: (round 123456)        # Format with three decimal places
-> "12.346"
: (round 123456 2)      # Format with two decimal places
-> "12.35"
: (format 123456 *Scl)  # Format with full precision
-> "12.3456"
</code></pre>

<dt><a name="rules"><code>(rules 'sym ..) -> sym</code></a>
<dd>Prints all rules defined for the <code>sym</code> arguments. See also <a
href="ref.html#pilog">Pilog</a> and <code><a href="refB.html#be">be</a></code>.

<pre><code>
: (rules 'member 'append)
1 (be member (@X (@X . @)))
2 (be member (@X (@ . @Y)) (member @X @Y))
1 (be append (NIL @X @X))
2 (be append ((@A . @X) @Y (@A . @Z)) (append @X @Y @Z))
-> append
</code></pre>

<dt><a name="run"><code>(run 'any ['cnt ['lst]]) -> any</code></a>
<dd>If <code>any</code> is an atom, <code>run</code> behaves like <code><a
href="refE.html#eval">eval</a></code>. Otherwise <code>any</code> is a list,
which is evaluated in sequence. The last result is returned. If a binding
environment offset <code>cnt</code> is given, that evaluation takes place in the
corresponding environment, and an optional <code>lst</code> of excluded symbols
can be supplied. See also <code><a href="refU.html#up">up</a></code>.

<pre><code>
: (run '((println (+ 1 2 3)) (println 'OK)))
6
OK
-> OK
</code></pre>

</dl>

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