




prompt-for-value message &key package initial-value value-function pane-args popup-args continuation
The function prompt-for-value prompts the user for a form and returns the result of evaluating that form.
The form is read in the 
package
 if specified or *package* if not and the result is the evaluation of the form. 
If initial-value is supplied it provides a default form.
If value-function is supplied it overrides the default value function which reads the form and evaluates it.
If 
continuation
 is non-nil, then it must be a function with a lambda list that accepts two arguments. The 
continuation
 function is called with the values that would normally be returned by prompt-for-value. On Cocoa, passing 
continuation
 causes the dialog to be made as a window-modal sheet and prompt-for-value returns immediately, leaving the dialog on the screen. The with-dialog-results macro provides a convenient way to create a 
continuation
 function.
The prompter is created by passing a text-input-pane to popup-confirmer. Arguments can be passed to the make-instance of the pane and the call to popup-confirmer using 
pane-args
 and 
popup-args
 respectively. 
(capi:prompt-for-value
"Square"
:initial-value '(+ 1 2 3)
:value-function
#'(lambda (text)
(let ((res (eval (read-from-string text))))
(* res res))))
CAPI User Guide and Reference Manual (Macintosh version) - 25 Feb 2015