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Standard­Condition­Predicates­Cowan

cowan
2010-07-09 20:07:42
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Standard predicates and accessors

Conditions created by the implementations are opaque objects as far as this standard is concerned. However, a variety of predicates and accessors are provided in order to help programs examine implementation-specific conditions. If a predicate returns #t on a particular condition, the related accessor(s) will return information, hopefully meaningful and useful. Otherwise, calling the accessors has undefined effect. It is common for more than one predicate to return #t on a particular condition.

Returns #t iff condition contains a string message describing the condition to humans.

Returns the message associated with message-condition.

Returns #t iff condition contains a string or symbol describing the object which is the source of the exception.

Returns the who object associated with who-condition.

Returns #t iff condition contains a list of objects providing additional information about the condition.

Returns the list of irritants (possibly empty) associated with message-condition.

Returns #t iff condition describes an exceptional situation that does not, in principle, prohibit immediate continued execution of the program, but may interfere with the program’s execution later.

Returns #t iff condition describes an exceptional situation that is serious enough that it cannot safely be ignored.

Returns #t iff condition describes an exceptional situation that is caused by something that has gone wrong in the interaction of the program with the external world or the user.

Returns #t iff condition describes an exceptional situation that is a violation of the language standard or a library standard, typically caused by a programming error.

Returns #t iff condition describes an invalid call to a procedure, such as passing an invalid number of arguments or passing an argument of the wrong type.

Returns #t iff condition describes a violation of an implementation restriction that is allowed by the specification.

Returns #t iff condition is reporting that storage is exhausted.

Returns #t iff condition describes a lexical syntax error or an error in parsing a datum.

Returns the string which could not be parsed.

Returns #t iff condition describes a syntax error.

Returns the form containing a syntax error.

Returns the subform which more precisely locates the syntax error.

Returns #t iff condition describes an undefined identifier.

Returns the identifier which is undefined as a symbol.

Returns #t iff condition describes a problem with a port.

Returns the port associated with port-condition.

Returns #t iff condition describes an exceptional situation with I/O.

Returns #t iff condition describes an exceptional situation with input.

Returns #t iff condition describes an exceptional situation with output.

Returns #t iff condition describes an invalid position of a port.

Returns the position specified by the user.

Returns #t iff condition has a filename associated with it.

Returns the filename associated with filename-condition as a string.

Returns #t iff condition describes a file protection violation.

Returns #t iff condition describes the existence or nonexistence of a file.

Returns #t the filename associated with filename-condition exists but should not, or #f if it does not exist but should.