CondWith

CondWith is a conceptual programming construct designed to combine conditional evaluation with a with-like resource management block. It allows a block of code to execute only when a boolean condition holds, while also ensuring that any resources acquired within the block are cleaned up automatically when the block exits. In proposed designs, CondWith can be implemented as a syntactic extension or macro that integrates conditional guards with scoped resource handling.

Semantics and design goals. The core idea of CondWith is to avoid boilerplate that separately checks a condition and then opens and closes resources. When the condition evaluates to true, CondWith enters a scoped region where resources can be acquired, bound, and used. Upon leaving the region, the resources are deterministically released. If the condition is false, the block is skipped entirely, and no side effects or resource allocations occur. Some variants include an optional else branch to define alternative behavior when the condition is false.

Syntax and usage. In pseudocode, CondWith might look like:

CondWith (condition) {

with resource as r {

// body using r

}

}

If condition is false, the body is not entered. In some proposals, an else clause can provide a fallback:

CondWith (condition) {

with resource as r {

// body

} else {

// fallback actions

}

}

Applications and discussion. CondWith is discussed in the context of languages that emphasize deterministic resource management and clean separation of concerns between control flow and resource lifetimes. It aims to reduce repetitive guards and streamline patterns that combine permission checks with resource use. Critics argue that it adds complexity and potential ambiguity with existing if and with constructs; practical adoption would require careful design to avoid confusion and to ensure clear semantics across compilers and runtimes.

See also. with statement, context manager, resource management, guard clauses.