Topic: alot of if statements

[andrew_nao]

I have alot of "if" statements

Code: [Select]

(if (= blockname "fmta12k6")
  (progn
     (load "a-xprt")
  )
that look like this
I know i can put them all in a cond statement but how do i get it to load the lisp files in the cond

[Lee Mac]

Code: [Select]

(cond
  (
    (eq blockname "fmta12k6")
   
    (load "a-xprt")
  )
  ( (eq blockname ...
  )
)
?

[ronjonp]

If you have a bunch of these you could also lump them into a list and use ASSOC to load:

Code: [Select]

(setq lst '(("fmta12k6" . "a-xprt")
    ("fmta12k6_2" . "a-xprt_2")
    ("fmta12k6_3" . "a-xprt_3")
    ("fmta12k6_4" . "a-xprt_4")
   )
)
;;Assoc is case sensitive
(if (setq tmp (assoc blockname lst))
  (load (cdr tmp))
)

[andrew_nao]

gah!

I had left the progn in my cond statements, thats why it didnt work for me.  :ugly:

thanks all for the help

[CAB]

The progn is ok to use but you may have placed it incorrectly.
This should still work:

Code: [Select]

(cond
  (
    (eq blockname "fmta12k6")
    
    (progn (load "a-xprt"))
  )
  ( (eq blockname ...
  )
)

[alanjt]

Side note, but still relevant: one should fill the second argument to ensure that an error is not thrown.
eg.

Code: [Select]

Command: (load "bread.lsp")

Error: LOAD failed: "bread.lsp"
Command: (load "bread.lsp" nil)
nil

Command: (load "bread.lsp" "you want bread, three dollars! no soup for you!")
"you want bread, three dollars! no soup for you!"
I prefer the nil option since I can then use a logical evaluation (or, and, if, etc.) to see if the desired routine actually loaded, since if loaded, it will return the symbol of the last loaded routine in the loaded file.

eg.

Code: [Select]

Command: (load "toggle.lsp" nil)
C:SSM
eg. (evaluation)

Code: [Select]

Command: (and (load "chicken.lsp" nil)) <<Nothing loaded, nil returned
nil

Command: (and (load "toggle.lsp" nil)) <<Code loaded, T returned
T

[CAB]

Good point Alan. 

[VovKa]

it will return the symbol of the last loaded routine in the loaded file.

what if the last symbol is nil? or the last expression evaluates to nil?
i use

Code: [Select]

(= (setq tmp (vk_RandNum)) (load "toggle" tmp))