Eeltingimust

Eeltingimust denotes a condition that must be true before an action or operation can proceed. It is a precondition that specifies the assumptions about inputs, state, or environment required for correct execution.

In software engineering, eeltingimust is part of contract-based design. It defines what a caller must ensure and what a callee can assume. If the eeltingimust is not met, the behavior is undefined, an error may be raised, or results may be incorrect. The responsibility for ensuring eeltingimust often lies with the caller, while postconditions describe the expected outcome after execution.

Common examples include a function divide(a, b) with the eeltingimus b != 0; a method access(index) requiring 0 <= index < length of the array; a user request requiring authentication. Preconditions can also concern resources, such as a file existing or a network connection being available.

Eeltingimust relates to other concepts such as postconditions and loop invariants. Design by Contract uses explicit preconditions and postconditions to specify correct behavior. They can be expressed in documentation, enforced by runtime checks or assertions, or supported by language features and formal methods.

Enforcement and testing involve checking the preconditions at the start of a function, potentially throwing an exception or returning an error when they are violated. Tests commonly cover both valid inputs that satisfy the preconditions and invalid inputs that should fail fast.

In practice, preconditions help clarify requirements, improve reliability and reusability of components, and assist static analysis. The term eeltingimust is the Estonian expression used to describe these prerequisites for operations, tasks, or procedures.