Loop over variables in Lisp

Question

I wrote the function

(defun test ()
  (let ((str1 "foo") (str2 "bar"))
    (loop for s in '(str1 str2) do (message s))))

but it does not work. The Elisp Backtrace message is:

Debugger entered--Lisp error: (wrong-type-argument stringp str1)

How can I make it work?

P.S.: the following modified version works perfectly, but I need the original version

(defun test1 ()
  (loop for s in '("asdf" "fdsa") do (message s)))

Svante · Accepted Answer · 2009-01-28 11:38:16Z

16

The quote operator (for which the apostrophe is syntactic sugar) means that its arguments are not evaluated, i.e. (quote (str1 str2)) returns a list of two symbols. Use list instead: (list str1 str2).

edited Jan 28, 2009 at 11:38

answered Jan 28, 2009 at 11:31

Svante

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Comments

Greg Hewgill · Accepted Answer · 2009-01-31 19:15:39Z

6

Build a list of the values:

(defun test ()
  (let ((str1 "foo") (str2 "bar"))
    (loop for s in (list str1 str2) do (message s))))

edited Jan 31, 2009 at 19:15

Greg Hewgill

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answered Jan 30, 2009 at 22:15

defstruct

Comments

dsm · Accepted Answer · 2009-01-28 10:58:52Z

3

try:

`(,str1 ,str2)

answered Jan 28, 2009 at 10:58

dsm

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1 Comment

HD. Over a year ago

A bit complex -- a simeple (list str1 str2) would do as well

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