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type-error-datum, type-error-expected-type

type-error-datum, type-error-expected-type Function

Syntax:

type-error-datum condition → datum

type-error-expected-type condition → expected-type

Arguments and Values:

condition—a condition of type type-error.

datum—an object.

expected-type—a type specifier .

Description:

type-error-datum returns the offending datum in the situation represented by the condition.

type-error-expected-type returns the expected type of the offending datum in the situation represented by the condition.

Examples:

(defun fix-digits (condition) 
  (check-type condition type-error) 
  (let\* ((digits ’(zero one two three four 
			 five six seven eight nine))  
	  (val (position (type-error-datum condition) digits))) 
	 (if (and val (subtypep ’fixnum (type-error-expected-type condition))) 
	     (store-value 7)))) 
(defun foo (x) 
  (handler-bind ((type-error #’fix-digits)) 
    (check-type x number) 
    (+ x 3))) 
(foo ’seven) 
→ 10

See Also:

type-error, Chapter 9 (Conditions)

Expanded Reference: type-error-datum, type-error-expected-type​

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(type-error-datum, type-error-expected-type )