# FilterLookupError

- **Package:** libtmux-swift
- **Language:** Swift
- **Kind:** enum
- **Source:** https://github.com/libtmux/libtmux-swift/blob/254f8b2be7eb60cacc3ffcb3ea8e456784f582df/Sources/LibTmux/FilterLookup.swift#L111
- **Page:** https://libtmux.org/en/swift/latest/reference/filterlookuperror/

Why a filter keyword could not be turned into a comparison.

Every case is a caller mistake caught before anything ran, so nothing was
sent and nothing needs undoing. The associated value names the part that
was wrong rather than repeating the whole keyword.

## Members

- `!=(_:_:)` (function): Returns a Boolean value indicating whether two values are not equal.
- `localizedDescription` (property): Retrieve the localized description for this error.
- `missingValue` (constant)
- `unknownField(_:)` (constant)
- `unknownOperator(_:)` (constant)
- `operatorNotSupported(_:)` (constant)
- `invalidRegularExpression(_:)` (constant)
- `valueNotOfFieldType(_:)` (constant)