CLHS: Function TYPE-ERROR-DATUM, TYPE-ERROR-EXPECTED-TYPE

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Function TYPE-ERROR-DATUM, TYPE-ERROR-EXPECTED-TYPE

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

Side Effects: None.

Affected By: None.

Exceptional Situations: None.

See Also:

type-error, Section 9 (Conditions)

Notes: None.

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