Prefix class for mandatory +relations. Note that this does not enforce any requirements by itself, it only returns an error message if the mis> message is explicitly called, e.g. by GUI functions. See also Database.

(rel nr (+Need +Key +Number))  # Item number is mandatory
Class for numeric relations, a subclass of +relation. Accepts an optional argument for the fixpoint scale (currently not used). See also Database.

(rel pr (+Number) 2)  # Price, with two decimal places
(n== 'any ..) -> flg
Returns T when not all any arguments are the same (pointer equality). (n== 'any ..) is equivalent to (not (== 'any ..)). See also == and Comparing.

: (n== 'a 'a)
-> NIL
: (n== (1) (1))
-> T
(n0 'any) -> flg
Returns T when any is not a number with value zero. See also =0, lt0, le0, ge0 and gt0.

: (n0 (- 6 3 2 1))
-> NIL
: (n0 'a)
-> T
(nT 'any) -> flg
Returns T when any is not the symbol T. See also =T.

: (nT 0)
-> T
: (nT "T")
-> T
: (nT T)
-> NIL
(name 'sym) -> sym
Returns a new transient symbol with the name of sym. See also str, sym, symbols, zap and intern.

: (name 'abc)
-> "abc"
: (name "abc")
-> "abc"
: (name '{A17})
-> "A17"
: (name (new))
-> NIL
(nand 'any ..) -> flg
Logical NAND. The expressions any are evaluated from left to right. If NIL is encountered, T is returned immediately. Else NIL is returned. (nand ..) is equivalent to (not (and ..)). See also and, nor, unless, ifn and nond.

: (nand (lt0 7) (read))
-> T
: (nand (lt0 -7) (read))
-> NIL
: (nand (lt0 -7) (read))
-> T
(native 'cnt1|sym1 'cnt2|sym2 'any 'any ..) -> any
Calls a native C function. The first argument should specify a shared object library, either "@" (the current main program), sym1 (a library path name), or cnt1 (a library handle obtained by a previous call). The second argument should be a symbol name sym2, or a function pointer cnt2 obtained by a previous call). Practically, the first two arguments will be always passed as transient symbols, which will get the library handle and function pointer assigned as values to be cached and used in subsequent calls. The third argument any is a result specification, while all following arguments are the arguments to the native function. The functionality is described in detail in Native C Calls.

The result specification may either be one of the atoms

   NIL   void
   B     byte     # Byte (unsigned 8 bit)
   C     char     # Character (UTF-8, 1-4 bytes)
   W     short    # Word (signed 16 bit)
   I     int      # Integer (signed 32 bit)
   N     long     # Number (signed 64 bit)
   P     void*    # Pointer (unsigned 64 bit)
   S     string   # String (UTF-8)
  -1.0   float    # Scaled fixpoint number
  +1.0   double   # Scaled fixpoint number
   T              # Direct Lisp value

or nested lists of these atoms with size specifications to denote arrays and structures, e.g.

   (N . 4)        # long[4];           -> (1 2 3 4)
   (N (C . 4))    # {long; char[4];}   -> (1234 ("a" "b" "c" NIL))
   (N (B . 7))    # {long; byte[7];}   -> (1234 (1 2 3 4 5 6 7))

Arguments can be

native takes care of allocating memory for strings, arrays or structures, and frees that memory when done.

For NaN or negative infinity fixpoint values NIL, and for positive infinity T is returned.

The C function may in turn call a function

   long lisp(char*, long, long, long, long, long);

which accepts a symbol name as the first argument, and up to 5 numbers. lisp() calls that symbol with the five numbers, and expects a numeric return value. "Numbers" in this context are 64-bit scalars, and may not only represent integers, but also pointers or other encoded data. See also %@, struct, lisp and errno.

: (native "@" "unlink" 'I "file")  # Same as (%@ "unlink" 'I "file")
-> 0
: (native "libcrypto.so" "SHA1" '(B . 20) "abcd" 4 0)
-> (129 254 139 254 135 87 108 62 203 34 66 111 142 87 132 115 130 145 122 207)
(need 'cnt ['lst ['any]]) -> lst
(need 'cnt ['num|sym]) -> lst
Produces a list of at least cnt elements. When called without optional arguments, a list of cnt NIL's is returned. When lst is given, it is extended to the left (if cnt is positive) or (destructively) to the right (if cnt is negative) with any elements. In the second form, a list of cnt atomic values is returned. See also range.

: (need 5)
-> (NIL NIL NIL NIL NIL)  # Allocate 5 cells
: (need 5 '(a b c))
-> (NIL NIL a b c)
: (need -5 '(a b c))
-> (a b c NIL NIL)
: (need 5 '(a b c) " ")  # String alignment
-> (" " " " a b c)
: (need 7 0)
-> (0 0 0 0 0 0 0)
: (need 5 (2 3) 1)
-> (1 1 1 2 3)
(new ['flg|num] ['typ ['any ..]]) -> obj
Creates and returns a new object. If flg is given and non-NIL, the new object will be an external symbol (created in database file 1 if T, or in the corresponding database file if num is given). typ (typically a list of classes) is assigned to the VAL, and the initial T message is sent with the arguments any to the new object. If no T message is defined for the classes in typ or their superclasses, the any arguments should evaluate to alternating keys and values for the initialization of the new object. See also box, object, class, type, isa, send and Database.

: (new)
-> $134426427
: (new T '(+Address))
-> {1A;3}
(new! 'typ ['any ..]) -> obj
Transaction wrapper function for new. (new! '(+Cls) 'key 'val ...) is equivalent to (dbSync) (new (db: +Cls) '(+Cls) 'key 'val ...) (commit 'upd). See also request!, set!, put! and inc!.

: (new! '(+Item)  # Create a new item
   'nr 2                      # Item number
   'nm "Spare Part"           # Description
   'sup (db 'nr '+CuSu 2)     # Supplier
   'inv 100                   # Inventory
   'pr 12.50 )                # Price
(next) -> any
Can only be used inside functions with a variable number of arguments (with @). Returns the next argument from the internal list. See also args, arg, rest, and pass.

: (de foo @ (println (next)))          # Print next argument
-> foo
: (foo)
-> NIL
: (foo 123)
-> 123
(nil . prg) -> NIL
Executes prg, and returns NIL. See also t, prog, prog1 and prog2.

: (nil (println 'OK))
-> NIL
Pilog predicate expects an argument variable, and succeeds if that variable is bound to NIL. See also not/1.

: (? @X NIL (nil @X))
-> NIL
(noLint 'sym)
(noLint 'sym|(sym . cls) 'sym2)
(Debug mode only) Excludes the check for a function definition of sym (in the first form), or for variable binding and usage of sym2 in the function definition, file contents or method body of sym (second form), during calls to lint. See also lintAll.

: (de foo ()
   (bar FreeVariable) )
-> foo
: (lint 'foo)
-> ((def bar) (bnd FreeVariable))
: (noLint 'bar)
-> bar
: (noLint 'foo 'FreeVariable)
-> (foo . FreeVariable)
: (lint 'foo)
-> NIL
(nond ('any1 . prg1) ('any2 . prg2) ..) -> any
Negated ("non-cond") multi-way conditional: If any of the anyN conditions evaluates to NIL, prgN is executed and the result returned. Otherwise (all conditions evaluate to non-NIL), NIL is returned. See also cond, ifn, unless, nor and nand.

: (nond
   ((= 3 3) (println 1))
   ((= 3 4) (println 2))
   (NIL (println 3)) )
-> 2
(nor 'any ..) -> flg
Logical NOR. The expressions any are evaluated from left to right. If a non-NIL value is encountered, NIL is returned immediately. Else T is returned. (nor ..) is equivalent to (not (or ..)). See also or, nand, unless, ifn and nond.

: (nor (lt0 7) (= 3 4))
-> T
(not 'any) -> flg
Logical negation. Returns T if any evaluates to NIL.

: (not (== 'a 'a))
-> NIL
: (not (get 'a 'a))
-> T
Pilog predicate that succeeds if and only if the goal cannot be proven. See also nil/1, true/0 and fail/0.

: (? (equal 3 4))
-> NIL
: (? (not (equal 3 4)))
-> T
(nsp 'sym) -> sym
Returns the (first) namespace where sym is found in, according to the current symbols search order. See also pico.

(load "@lib/gis.l")

: (symbols '(gis pico))
-> (pico)
gis: (nsp 'gis)
-> pico
gis: (nsp 'Zoom)
-> gis
gis: (nsp 'osmStat)
-> gis
(nth 'lst 'cnt ..) -> lst
Returns the tail of lst starting from the cnt'th element of lst. Successive cnt arguments operate on the CARs of the results in the same way. (nth 'lst 2) is equivalent to (cdr 'lst). See also get.

: (nth '(a b c d) 2)
-> (b c d)
: (nth '(a (b c) d) 2 2)
-> (c)
: (cdadr '(a (b c) d))
-> (c)
(num? 'any) -> num | NIL
Returns any when the argument any is a number, otherwise NIL. See also sym?, atom and pair.

: (num? 123)
-> 123
: (num? (1 2 3))
-> NIL