CurrentModule = MathOptInterface
DocTestSetup = quote
    import MathOptInterface as MOI
end
DocTestFilters = [r"MathOptInterface|MOI"]

Errors

When an MOI call fails on a model, precise errors should be thrown when possible instead of simply calling error with a message. The docstrings for the respective methods describe the errors that the implementation should throw in certain situations. This error-reporting system allows code to distinguish between internal errors (that should be shown to the user) and unsupported operations which may have automatic workarounds.

When an invalid index is used in an MOI call, an InvalidIndex is thrown:

InvalidIndex

When an invalid result index is used to retrieve an attribute, a ResultIndexBoundsError is thrown:

ResultIndexBoundsError
check_result_index_bounds

As discussed in JuMP mapping, for scalar constraint with a nonzero function constant, a ScalarFunctionConstantNotZero exception may be thrown:

ScalarFunctionConstantNotZero

Some VariableIndex constraints cannot be combined on the same variable:

LowerBoundAlreadySet
UpperBoundAlreadySet

As discussed in AbstractCallback, trying to get attributes inside a callback may throw:

OptimizeInProgress

Trying to submit the wrong type of AbstractSubmittable inside an AbstractCallback (for example, a UserCut inside a LazyConstraintCallback) will throw:

InvalidCallbackUsage

The rest of the errors defined in MOI fall in two categories represented by the following two abstract types:

UnsupportedError
NotAllowedError

The different UnsupportedError and NotAllowedError are the following errors:

UnsupportedAttribute
GetAttributeNotAllowed
SetAttributeNotAllowed
AddVariableNotAllowed
UnsupportedConstraint
AddConstraintNotAllowed
ModifyConstraintNotAllowed
ModifyObjectiveNotAllowed
DeleteNotAllowed
UnsupportedSubmittable
SubmitNotAllowed
UnsupportedNonlinearOperator

Note that setting the ConstraintFunction of a VariableIndex constraint is not allowed:

SettingVariableIndexNotAllowed