I want to run a function but not have it output the result in the terminal. For example, (set 'A 'B) normally returns B in the console like the following:
>>> (set 'A 'B)
B
>>> A
B
I don't want it to return anything; I still want the function to do what it's supposed to, just silently:
>>> (set 'A 'B)
>>> A
B
It's not perfect, but you can use (values) at the end of your expression to suppress output. You get a blank line instead.
Common Lisp:
(progn (set 'A 'B) (values))
I'm not sure of the equivalent in Scheme.
A lisp REPL always prints some return value. If you really didn't want output, you could run your code as a script in the terminal.
Example:
#!/path/to/interpreter
(set 'A 'B)
[rest of program]
I came to the same solution as user1613254, however I made a macro for this (have it in my .sbclrc):
(defmacro m-ignore (fun &body body)
"ignores the return value of a function"
`(progn (,fun ,@body)
(values)))
You use it like this:
(m-ignore format t "text")
The output would be:
text
instead of:
text
NIL
which would be printed when using
(format t "text")
