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Kompottkin

Cool! I've been wanting to play around with 4store for a while now. Maybe I can finally get around to doing so.

Kompottkin

P.D.Q. Bach.

Kompottkin

You can convert rationals to floats: (float (+ 232/100 1/1000)) -> 2.321 Technically, that (somewhat) reintroduces the problem... L> (format t "~E" (float (+ 232/100 1/1000))) 2.3210001e+0 NIL L> (= 2.3210001 (float (+ 232/100 1/1000))) T The Right Thing[TM] would be to use something like...

Kompottkin

hajovonta wrote:Maybe it was my high expectations

If you want exact rationals, use exact rationals.

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CL-USER> (+ 232/100 1/1000)
2321/1000

Kompottkin

samohtvii wrote:I'm also looking to take a string and 'inspect' the first character so with : "example" i would want to get e as a variable.

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CL-USER> (char "example" 0)
#\e

Kompottkin

cos wrote:Why does first return 1, second return 2, and last return (3)?

The reason is that LAST does not return the last element of a list, but actually a list of the last N elements (actually the last N cons-cells), where N happens to default to 1:

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(last '(1 2 3) 2)
(2 3)

Kompottkin

Also:

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CL-USER(1): (defvar *x* (make-point2d :x 10 :y 20))
*X*
CL-USER(2): (mapcan #'(lambda (slot-name) (list slot-name (slot-value *x* slot-name))) (mapcar #'sb-mop:slot-definition-name (sb-mop:class-slots (class-of *x*))))
(X 10 Y 20)

Kompottkin

mparsa wrote:I want to get the value of the b

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CL-USER(3): (defstruct point2d x y)
POINT2D
CL-USER(4): (make-point2d :x 1 :y 2)
#S(POINT2D :X 1 :Y 2)
CL-USER(5): (slot-value * 'x)
1
CL-USER(6): (slot-value ** 'y)
2

Kompottkin

Setting a variable at the top level sets the global value of the variable without proclaiming it special. Yes, it does on some implementations, but conforming programs may not rely on this behavior. In Lisp you don't need to declare or define variables. But if you bind a variable like in (let ((x 1...

Kompottkin

The MOP functions illustrated by the following REPL transcript might or might not be useful: CL-USER(1): (defstruct point x y) POINT CL-USER(2): (defvar *a* (make-point :x 10 :y 20)) *A* CL-USER(3): *a* #S(POINT :X 10 :Y 20) CL-USER(4): (sb-mop:class-slots (class-of *a*)) (#<SB-PCL::STRUCTURE-EFFECT...

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