# LibTmux.FSharp.Filter

- **Module:** LibTmux.FSharp
- **Package:** LibTmux.FSharp
- **Language:** F#
- **Kind:** class
- **Source:** https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/src/LibTmux.FSharp/Query.fsi#L11
- **Page:** https://libtmux.org/en/fsharp/latest/reference/libtmux-fsharp-filter/

```
type Filter

module Filter
```

Describes a validated portable predicate over one entity type.

## Members

### Common operations

- `all` (function): Requires every child to match, returning true for an empty captured relation.
- `any` (function): Requires a matching child, returning false for an empty captured relation.
- `matches` (function): Matches a string against a culture-invariant .NET regular expression.
- `none` (function): Requires no matching child, returning true for an empty captured relation.
- `allOf` (function): Requires every predicate in order; an empty list matches everything.
- `anyOf` (function): Requires at least one predicate in order; an empty list matches nothing.
- `contains` (function): Matches a string containing a substring.
- `containsIgnoreCase` (function): Matches a string containing a substring ignoring case.
- `endsWith` (function): Matches a string suffix.
- `endsWithIgnoreCase` (function): Matches a string suffix ignoring case.
- `eq` (function): Matches a field equal to a constant.
- `eqIgnoreCase` (function): Matches a string equal to a constant ignoring case.
- `ge` (function): Matches a count at least a constant.
- `gt` (function): Matches a count above a constant.
- `isNull` (function): Matches a captured null string without treating an uncaptured field as absent.
- `le` (function): Matches a count at most a constant.
- `lt` (function): Matches a count below a constant.
- `matchesIgnoreCase` (function): Matches a string against a culture-invariant .NET regular expression ignoring case.
- `ne` (function): Matches a field not equal to a constant.
- `negate` (function): Negates a portable predicate.
- `notOneOf` (function): Matches no constant in a list; an empty list matches everything.
- `oneOf` (function): Matches any constant in a list; an empty list matches nothing.
- `startsWith` (function): Matches a string prefix.
- `startsWithIgnoreCase` (function): Matches a string prefix ignoring case.

### Other members

- `toDocument` (function): Returns the core document validated when the filter was constructed.
- `toPredicate` (function): Returns a predicate compiled once for native lazy filtering.