| |
ANSI Common Lisp  25 Environment 25.2 Dictionary of Environment
| 25.2.21 +, ++, +++ |
Variable |
- Value Type:
-
an object.
- Initial Value:
-
implementation-dependent.
- Description:
-
The variables +, ++, and +++ are maintained by the
Lisp read-eval-print loop to save forms that were
recently evaluated.
The value of + is the last form that was evaluated,
the value of ++ is the previous value of +, and
the value of +++ is the previous value of ++.
- Examples:
-
(+ 0 1)  1
(- 4 2) 2
(/ 9 3) 3
(list + ++ +++) ((/ 9 3) (- 4 2) (+ 0 1))
(setq a 1 b 2 c 3 d (list a b c)) (1 2 3)
(setq a 4 b 5 c 6 d (list a b c)) (4 5 6)
(list a b c) (4 5 6)
(eval +++) (1 2 3)
#.`(,@++ d) (1 2 3 (1 2 3))
- Affected By:
-
Lisp read-eval-print loop.
- See Also:
-
- (variable),
* (variable),
/ (variable),
Section 25.1.1 Top level loop
- Allegro CL Implementation Details:
-
None.
|
