Simple rule matcher for PowerShell. Allows writing logic as a class that will match any or all of the predicates and optionally return a value on match.

IRule.ps1

class IRule {
    [System.Collections.Generic.IEnumerable[IRule]]$Rules
    
    # Or,  Any : bail on first match
    # And, All : evaluate all rules, only return a result if they all succeed
    [ValidateSet("Or","Any",  "And", "All")]
    $MatchType

    # Called on matching rules, overload in an inherited class to return
    # values relevant to that rule.
    [object] OnMatch ($input) { return $null }

    # Execute matches on the collection of rules or overload in an
    # inherited class to define the rule predicate.
    [object[]] Matches ($input) {
        switch ($this.MatchType) {
            { 'Or' -or 'Any' } {
                $match = $this.Rules.Where({ $_.Matches($input) }, 'First')
                if ($match) { 
                    return $match.OnMatch($input) 
                }
                return $null
            }
            { 'And' -or 'All' } {
                $match, $else = $this.Rules.Where({ $_.Matches($input) -eq $true }, 'Split')
                if ($match -and -not $else) {
                    $results = $match | foreach { $_.OnMatch($input) }
                    if (-not $results) { return $true }
                    return $results
                }
            }
        }

        return $null
    }
}