A global variable holding the temporary directory name created with tmp. See also *Bye.

: *Bye
-> ((saveHistory) (and *Tmp (call 'rm "-r" *Tmp)))
: (tmp "foo" 123)
-> "/home/app/.pil/tmp/27140/foo123"
: *Tmp
-> "/home/app/.pil/tmp/27140/"
Class for clock time values (as calculated by time), a subclass of +Number. See also Database.

(rel tim (+Time))  # Time of the day
A global constant, evaluating to itself. T is commonly returned as the boolean value "true" (though any non-NIL values could be used). It represents the absolute maximum, as it is larger than any other object. As a property key, it is used to store Pilog clauses, and inside Pilog clauses it is the cut operator. See also NIL and and Comparing.

: T
-> T
: (= 123 123)
-> T
: (get 'not T)
-> ((@P (1 (-> @P)) T (fail)) (@P))
Holds the current object during method execution (see OO Concepts), or inside the body of a with statement. As it is a normal symbol, however, it can be used in normal bindings anywhere. See also isa, :, =:, :: and var:.

: (with 'X (println 'This 'is This))
This is X
-> X
: (put 'X 'a 1)
-> 1
: (put 'X 'b 2)
-> 2
: (put 'Y 'a 111)
-> 111
: (put 'Y 'b 222)
-> 222
: (mapcar '((This) (cons (: a) (: b))) '(X Y))
-> ((1 . 2) (111 . 222))
(t . prg) -> T
Executes prg, and returns T. See also nil, prog, prog1 and prog2.

: (t (println 'OK))
-> T
(tab 'lst 'any ..) -> NIL
Print all any arguments in a tabular format. lst should be a list of numbers, specifying the field width for each argument. All items in a column will be left-aligned for negative numbers, otherwise right-aligned. See also align, center and wrap.

: (let Fmt (-3 14 14)
   (tab Fmt "Key" "Rand 1" "Rand 2")
   (tab Fmt "---" "------" "------")
   (for C '(A B C D E F)
      (tab Fmt C (rand) (rand)) ) )
Key        Rand 1        Rand 2
---        ------        ------
A               0    1481765933
B     -1062105905    -877267386
C      -956092119     812669700
D       553475508   -1702133896
E      1344887256   -1417066392
F      1812158119   -1999783937
-> NIL
(tail 'cnt|lst 'lst) -> lst
Returns the last cnt elements of lst. If cnt is negative, it is added to the length of lst. If the first argument is a lst, tail is a predicate function returning that argument list if it is equal to the tail of the second argument, and NIL otherwise. (tail -2 Lst) is equivalent to (nth Lst 3). See also offset, head, last and stem.

: (tail 3 '(a b c d e f))
-> (d e f)
: (tail -2 '(a b c d e f))
-> (c d e f)
: (tail 0 '(a b c d e f))
-> NIL
: (tail 10 '(a b c d e f))
-> (a b c d e f)
: (tail '(d e f) '(a b c d e f))
-> (d e f)
(task 'num ['num] [sym 'any ..] [. prg]) -> lst
A front-end to the *Run global. If called with only a single num argument, the corresponding entry is removed from the value of *Run. Otherwise, a new entry is created. If an entry with that key already exists, an error is issued. For negative numbers, a second number must be supplied. If sym/any arguments are given, a job environment is built for the *Run entry. See also tasks, forked and timeout.

: (task -10000 5000 N 0 (msg (inc 'N)))            # Install task
-> (-10000 5000 (job '((N . 0)) (msg (inc 'N))))   # for every 10 seconds
: 1                                                # ... after 5 seconds
2                                                  # ... after 10 seconds
3                                                  # ... after 10 seconds
(task -10000)                                      # remove again
-> NIL

: (task (port T 4444) (eval (udp @)))              # Receive RPC via UDP
-> (3 (eval (udp @)))

# Another session (on the same machine)
: (udp "localhost" 4444 '(println *Pid))  # Send RPC message
-> (println *Pid)
(tasks . prg)
Runs a task with variable event specification in a single *Run entry. The task body prg should return either a positive number (a file descriptor) or a negative number (a timeout value) to be used in the next iteration. The first value must be a timeout. A value of NIL removes the task. Uses -2 as implicit key. See also forked and timeout.

(tasks  # Three iterations with varying timeout
   (let X (pop '(((-1000 . a) (-4000 . b) (-1000 . c))))
      (msg (cdr X))
      (car X) ) )

   (co 'echoes  # Coroutine
      (use S
         (loop  # Loop infinitely
            (yield -4000)  # First wait 4 seconds
            (msg 'OK)
            (yield  # Then wait for remote data
               (setq S
                  (pipe (exec "sh" "-c" "sleep 2; echo 7")) ) )
            (msg (in S (read)))
            (close S) ) ) ) )
(telStr 'sym) -> sym
Formats a telephone number according to the current locale. If the string head matches the local country code, it is replaced with the national trunk prefix, otherwise + is prepended. See also expTel, datStr, money and format.

: (telStr "49 1234 5678-0")
-> "+49 1234 5678-0"
: (locale "DE" "de")
-> NIL
: (telStr "49 1234 5678-0")
-> "01234 5678-0"
(tell ['cnt] 'sym ['any ..]) -> any
Family IPC: Send an executable list (sym any ..) to all family members (i.e. all children of the current process, and all other children of the parent process, see fork) for automatic execution. When the cnt argument is given and non-zero, it should be the PID of such a process, and the list will be sent only to that process. When called without arguments, no message is actually sent, and the parent process may grant sync to the next waiting process. tell is also used internally by commit to notify about database changes. When called explicitly, the size of the message is limited to the POSIX constant PIPE_BUF. See also kids, detach and hear.

: (call 'ps "x")                          # Show processes
 1321 pts/0    S      0:00 /usr/bin/picolisp ..  # Parent process
 1324 pts/0    S      0:01 /usr/bin/picolisp ..  # First child
 1325 pts/0    S      0:01 /usr/bin/picolisp ..  # Second child
 1326 pts/0    R      0:00 ps x
-> T
: *Pid                                    # We are the second child
-> 1325
: (tell 'println '*Pid)                   # Ask all others to print their Pid's
-> *Pid
(test 'any . prg)
Executes prg, and issues an error if the result does not match the any argument. See also assert.

: (test 12 (* 3 4))
-> NIL
: (test 12 (+ 3 4))
((+ 3 4))
12 -- 'test' failed
(text 'any1 'any ..) -> sym
Builds a new transient symbol (string) from the string representation of any1, by replacing all occurrences of an at-mark "@", followed by one of the letters "1" through "9", and "A" through "Z", with the corresponding any argument. In this context "@A" refers to the 10th argument. A literal at-mark in the text can be represented by two successive at-marks. See also pack and glue.

: (text "abc @1 def @2" 'XYZ 123)
-> "abc XYZ def 123"
: (text "a@@bc.@1" "de")
-> "a@bc.de"
(throw 'sym 'any)
Non-local jump into a previous catch environment with the jump label sym (or T as a catch-all). Any pending finally expressions are executed, local symbol bindings are restored, open files are closed and internal data structures are reset appropriately, as the environment was at the time when the corresponding catch was called. Then any is returned from that catch. See also quit.

: (de foo (N)
   (println N)
   (throw 'OK) )
-> foo
: (let N 1  (catch 'OK (foo 7))  (println N))
-> 1
(tick (cnt1 . cnt2) . prg) -> any
Executes prg, then (destructively) adds the number of elapsed user ticks to the cnt1 parameter, and the number of elapsed system ticks to the cnt2 parameter. Thus, cnt1 and cnt2 will finally contain the total number of user and system time ticks spent in prg and all functions called (this works also for recursive functions). For execution profiling, tick is usually inserted into words with prof, and removed with unprof. See also usec.

: (de foo ()                        # Define function with empty loop
   (tick (0 . 0) (do 100000000)) )
-> foo
: (foo)                             # Execute it
-> NIL
: (pp 'foo)
(de foo NIL
   (tick (97 . 0) (do 100000000)) ) # 'tick' incremented 'cnt1' by 97
-> foo
(till 'any ['flg]) -> lst|sym
Reads from the current input channel till a character contained in any is found (or until end of file if any is NIL). If flg is NIL, a list of single-character transient symbols is returned. Otherwise, a single string is returned. See also from and line.

: (till ":")
-> ("a" "b" "c")
: (till ":" T)
-> "abc"
(tim$ 'tim ['flg]) -> sym
Formats a time tim. If flg is NIL, the format is HH:MM, otherwise it is HH:MM:SS. See also $tim and dat$.

: (tim$ (time))
-> "10:57"
: (tim$ (time) T)
-> "10:57:56"
(time ['T]) -> tim
(time 'tim) -> (h m s)
(time 'h 'm ['s]) -> tim | NIL
(time '(h m [s])) -> tim | NIL
Calculates the time of day, represented as the number of seconds since midnight. When called without arguments, the current local time is returned. When called with a T argument, the time of the last call to date is returned. When called with a single number tim, it is taken as a time value and a list with the corresponding hour, minute and second is returned. When called with two or three numbers (or a list of two or three numbers) for the hour, minute (and optionally the second), the corresponding time value is returned (or NIL if they do not represent a legal time). See also date, stamp, usec, tim$ and $tim.

: (time)                         # Now
-> 32334
: (time 32334)                   # Now
-> (8 58 54)
: (time 12 70)                   # Illegal time
-> NIL
(timeout ['num])
Sets or refreshes a timeout value in the *Run global, so that the current process executes bye after the given period. If called without arguments, the timeout is removed. Uses -1 as implicit key. See also task.

: (timeout 3600000)           # Timeout after one hour
-> (-1 3600000 (bye))
: *Run                        # Look after a few seconds
-> ((-1 3574516 (bye)))
(tmp ['any ..]) -> sym
Returns the path name to the packed any arguments in a process-local temporary directory. The directory name consists of the path to ".pil/tmp/" in the user's home directory, followed by the current process ID *Pid. This directory is automatically created if necessary, and removed upon termination of the process (bye). See also pil, *Tmp and *Bye .

: *Pid
-> 27140
: (tmp "foo" 123)
-> "/home/app/.pil/tmp/27140/foo123"
: (out (tmp "foo" 123) (println 'OK))
-> OK
: (dir (tmp))
-> ("foo123")
: (in (tmp "foo" 123) (read))
-> OK
Pilog predicate that succeeds if the first argument, after folding it to a canonical form, is either a substring or a +Sn soundex match of the result of applying the get algorithm to the following arguments. Typically used as filter predicate in select/3 database queries. See also isa/2, same/3, bool/3, range/3, head/3, fold/3 and part/3.

: (?
   @Nr (1 . 5)
   @Nm "Sven"
   (select (@CuSu)
      ((nr +CuSu @Nr) (nm +CuSu @Nm))
      (range @Nr @CuSu nr)
      (tolr @Nm @CuSu nm) )
   (val @Name @CuSu nm) )
 @Nr=(1 . 5) @Nm="Sven" @CuSu={2-2} @Name="Seven Oaks Ltd."
(touch 'sym) -> sym
When sym is an external symbol, it is marked as "modified" so that upon a later commit it will be written to the database file. An explicit call of touch is only necessary when the value or properties of sym are indirectly modified.

: (get '{2} 'lst)
-> (1 2 3 4 5)
: (set (cdr (get (touch '{2}) 'lst)) 999)    # Only read-access, need 'touch'
-> 999
: (get '{2} 'lst)                            # Modified second list element
-> (1 999 3 4 5)
(trace 'sym) -> sym
(trace 'sym 'cls) -> sym
(trace '(sym . cls)) -> sym
(Debug mode only) Inserts a $ trace function call at the beginning of the function or method body of sym, so that trace information will be printed before and after execution. Can only be used with EXPRs and SUBRs. Built-in functions (SUBRs) are automatically converted to Lisp expressions (see expr). See also *Dbg, traceAll and untrace, debug and lint.

: (trace '+)
-> +
: (+ 3 4)
 + : 3 4
 + = 7
-> 7
(traceAll ['lst]) -> sym
(Debug mode only) Traces all Lisp level functions by inserting a $ function call at the beginning. lst may contain symbols which are to be excluded from that process. In addition, all symbols in the global variable *NoTrace are excluded. See also trace, untrace and *Dbg.

: (traceAll)      # Trace all Lisp level functions
-> balance
(trail ['flg]) -> lst
(64-bit version only) Returns a stack backtrace for the current point of program execution. The list elements are either list expressions (denoting function or method calls), or symbols followed by their corresponding values. If flg is NIL, the symbols and their values are omitted, and only the expressions are returned. See also bt, up and env.

: (de f (A B)
   (g (inc A) (dec B)) )
-> f
: (de g (X Y)
   (trail T) )
-> g
: (f 3 4)
-> ((f 3 4) A 3 B 4 (g (inc A) (dec B)) X 4 Y 3)
(tree 'sym 'cls ['hook]) -> tree
Returns a data structure specifying a database index tree. sym and cls determine the relation, with an optional hook object. See also root, fetch, store, count, leaf, minKey, maxKey, init, step, scan, iter, prune, zapTree and chkTree.

: (tree 'nm '+Item)
-> (nm . +Item)
(trim 'lst) -> lst
Returns a copy of lst with all trailing whitespace characters or NIL elements removed. See also clip.

: (trim (1 NIL 2 NIL NIL))
-> (1 NIL 2)
: (trim '(a b " " " "))
-> (a b)
Pilog predicate that always succeeds. See also fail/0 and repeat/0.

:  (? (true))
-> T
(try 'msg 'obj ['any ..]) -> any
Tries to send the message msg to the object obj, optionally with arguments any. If obj is not an object, or if the message cannot be located in obj, in its classes or superclasses, NIL is returned. See also OO Concepts, send, method, meth, super and extra.

: (try 'msg> 123)
-> NIL
: (try 'html> 'a)
-> NIL
(type 'any) -> lst
Return the type (list of classes) of the object sym. See also OO Concepts, isa, class, new and object.

: (type '{1A;3})
: (type '+DnButton)
-> (+Tiny +Rid +JS +Able +Button)
(tzo) -> cnt
Return the time zone offset, i.e. the number of seconds east of Coordinated Universal Time (UTC). Supported only on Linux. See also date and time.

: (tzo)
-> 3600