Factored out matching lists of regular expressions.

internal/filter/filter.go

@@ -0,0 +1,42 @@
+// This file is Free Software under the MIT License
+// without warranty, see README.md and LICENSES/MIT.txt for details.
+//
+// SPDX-License-Identifier: MIT
+//
+// SPDX-FileCopyrightText: 2023 German Federal Office for Information Security (BSI) <https://www.bsi.bund.de>
+// Software-Engineering: 2023 Intevation GmbH <https://intevation.de>
+
+// Package filter implements helps to filter advisories.
+package filter
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// PatternMatcher is a list of regular expressions.
+type PatternMatcher []*regexp.Regexp
+
+// NewPatternMatcher compiles a new list of regular expression from
+// a given list of strings.
+func NewPatternMatcher(patterns []string) (PatternMatcher, error) {
+	pm := make(PatternMatcher, 0, len(patterns))
+	for _, pattern := range patterns {
+		expr, err := regexp.Compile(pattern)
+		if err != nil {
+			return nil, fmt.Errorf("invalid ignore pattern: %w", err)
+		}
+		pm = append(pm, expr)
+	}
+	return pm, nil
+}
+
+// Matches returns true if the given string matches any of the expressions.
+func (pm PatternMatcher) Matches(s string) bool {
+	for _, expr := range pm {
+		if expr.MatchString(s) {
+			return true
+		}
+	}
+	return false
+}