V

(val 'var) -> any

Returns the current value of var. See also setq, set and def.

: (setq L '(a b c))
-> (a b c)
: (val 'L)
-> (a b c)
: (val (cdr L))
-> b

val/3

Pilog predicate that returns the value of an object's attribute. Typically used in database queries. The first argument is a Pilog variable to bind the value, the second is the object, and the third and following arguments are used to apply the get algorithm to that object. See also db/3 and select/3.

: (?
   (db nr +Item (2 . 5) @Item)   # Fetch articles 2 through 5
   (val @Nm @Item nm)            # Get item description
   (val @Sup @Item sup nm) )     # and supplier's name
 @Item={3-2} @Nm="Spare Part" @Sup="Seven Oaks Ltd."                             @Item={3-3} @Nm="Auxiliary Construction" @Sup="Active Parts Inc."
 @Item={3-4} @Nm="Enhancement Additive" @Sup="Seven Oaks Ltd."
 @Item={3-5} @Nm="Metal Fittings" @Sup="Active Parts Inc."
-> NIL

(var sym . any) -> any

Defines a class variable sym with the initial value any for the current class (in *Class). See also OO Concepts and var:.

: (class +A)
-> +A
: (var a . 1)
-> 1
: (var b . 2)
-> 2
: (show '+A)
+A NIL
   b 2
   a 1
-> +A

(var: sym) -> any

Fetches the value of a class variable sym for the current object This, by searching the property lists of its class(es) and supperclasses. See also OO Concepts, var, with, meta, :, =: and ::.

: (object 'O '(+A) 'a 9 'b 8)
-> O
: (with 'O (list (: a) (: b) (var: a) (var: b)))
-> (9 8 1 2)

(version ['flg]) -> lst

(64-bit version only) Prints the current version as a string of dot-separated numbers, and returns the current version as a list of numbers. When flg is non-NIL, printing is suppressed.

$ ./p -version
3.0.1.22
: (version T)
-> (3 0 1 22)

(vi 'sym) -> sym

(vi 'sym 'cls) -> sym

(vi '(sym . cls)) -> sym

(vi) -> NIL

Opens the "vi" editor on the function or method definition of sym. A call to ld thereafter will load the modified file. See also doc, pp, *Dbg, debug and pp.

: (vi 'url> '+CuSu)  # Edit the method's source code, then exit from 'vi'
-> T

(view 'lst) -> any

Views lst as tree-structured ASCII graphics. See also pretty and show.

: (view '(a (b c d) (e (f (g) (h) (i)) (j (k) (l) (m))) (n o p) q))
+-- a
|
+---+-- b
|   |
|   +-- c
|   |
|   +-- d
|
+---+-- e
|   |
|   +---+-- f
|   |   |
|   |   +---+-- g
|   |   |
|   |   +---+-- h
|   |   |
|   |   +---+-- i
|   |
|   +---+-- j
|       |
|       +---+-- k
|       |
|       +---+-- l
|       |
|       +---+-- m
|
+---+-- n
|   |
|   +-- o
|   |
|   +-- p
|
+-- q