Quintus Prolog

Error Classes

ref-ere-err-ins: Instantiation Errors
ref-ere-err-typ: Type Errors
ref-ere-err-dom: Domain Errors
ref-ere-err-ran: Range Errors
ref-ere-err-rep: Representation Errors
ref-ere-err-exi: Existence Errors
ref-ere-err-per: Permission Errors
ref-ere-err-con: Context Errors
ref-ere-err-cns: Consistency Errors
ref-ere-err-syn: Syntax Errors
ref-ere-err-res: Resource Errors
ref-ere-err-sys: System Errors

Exceptions raised by the Prolog system are called errors. The set of exception classes used by the system has been kept small. Here is a complete list:

Instantiation Error: An input argument is insufficiently instantiated.
Type Error: An input argument is of the type.
Domain Error: An input argument is illegal but of the right type.
Range Error: A value specified for an output argument is illegal.
Representation Error: A computed value cannot be represented.
Existence Error: Something does not exist.
Permission Error: Specified operation is not permitted.
Context Error: Specified operation is not permitted in this context.
Consistency Error: Two otherwise correct values are inconsistent with each other.
Syntax Error: Error in reading a term.
Resource Error: Some resource limit has been exceeded.
System Error: An error detected by the operating system.

The exception codes corresponding to these classes are:

instantiation_error(Goal, ArgNo)
type_error(Goal, ArgNo, TypeName, Culprit)
domain_error(Goal, ArgNo, DomainName, Culprit, Message)
range_error(Goal, ArgNo, TypeName, Culprit)
representation_error(Goal, ArgNo, Message)
existence_error(Goal, ArgNo, ObjectType, Culprit, Message)
permission_error(Goal, Operation, ObjectType, Culprit, Message)
context_error(Goal, ContextType, CommandType)
consistency_error(Goal, Culprit1, Culprit2, Message)
syntax_error(Goal, Position, Message, Left, Right)
resource_error(Goal, Resource, Message)
system_error(Message)

Most exception codes include a copy of the Goal that raised the exception.

In general, built-in predicates that cause side-effects, such as the opening of a stream or asserting a clause into the Prolog database, attempt to do all error checking before the side-effect is performed. Unless otherwise indicated in the documentation for a particular predicate or error class, it should be assumed that goals that raise exceptions have not performed any side-effect.