Merging upstream version 2.0.3+dfsg (Closes: #923993, #1042533, #1045145).

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 101 insertions, 0 deletions

diff --git a/src/go/pkg/matcher/logical.go b/src/go/pkg/matcher/logical.go
new file mode 100644
index 000000000..af07be8f4
--- /dev/null
+++ b/src/go/pkg/matcher/logical.go
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package matcher
+
+type (
+	trueMatcher  struct{}
+	falseMatcher struct{}
+	andMatcher   struct{ lhs, rhs Matcher }
+	orMatcher    struct{ lhs, rhs Matcher }
+	negMatcher   struct{ Matcher }
+)
+
+var (
+	matcherT trueMatcher
+	matcherF falseMatcher
+)
+
+// TRUE returns a matcher which always returns true
+func TRUE() Matcher {
+	return matcherT
+}
+
+// FALSE returns a matcher which always returns false
+func FALSE() Matcher {
+	return matcherF
+}
+
+// Not returns a matcher which positive the sub-matcher's result
+func Not(m Matcher) Matcher {
+	switch m {
+	case TRUE():
+		return FALSE()
+	case FALSE():
+		return TRUE()
+	default:
+		return negMatcher{m}
+	}
+}
+
+// And returns a matcher which returns true only if all of it's sub-matcher return true
+func And(lhs, rhs Matcher, others ...Matcher) Matcher {
+	var matcher Matcher
+	switch lhs {
+	case TRUE():
+		matcher = rhs
+	case FALSE():
+		matcher = FALSE()
+	default:
+		switch rhs {
+		case TRUE():
+			matcher = lhs
+		case FALSE():
+			matcher = FALSE()
+		default:
+			matcher = andMatcher{lhs, rhs}
+		}
+	}
+	if len(others) > 0 {
+		return And(matcher, others[0], others[1:]...)
+	}
+	return matcher
+}
+
+// Or returns a matcher which returns true if any of it's sub-matcher return true
+func Or(lhs, rhs Matcher, others ...Matcher) Matcher {
+	var matcher Matcher
+	switch lhs {
+	case TRUE():
+		matcher = TRUE()
+	case FALSE():
+		matcher = rhs
+	default:
+		switch rhs {
+		case TRUE():
+			matcher = TRUE()
+		case FALSE():
+			matcher = lhs
+		default:
+			matcher = orMatcher{lhs, rhs}
+		}
+	}
+	if len(others) > 0 {
+		return Or(matcher, others[0], others[1:]...)
+	}
+	return matcher
+}
+
+func (trueMatcher) Match(_ []byte) bool       { return true }
+func (trueMatcher) MatchString(_ string) bool { return true }
+
+func (falseMatcher) Match(_ []byte) bool       { return false }
+func (falseMatcher) MatchString(_ string) bool { return false }
+
+func (m andMatcher) Match(b []byte) bool       { return m.lhs.Match(b) && m.rhs.Match(b) }
+func (m andMatcher) MatchString(s string) bool { return m.lhs.MatchString(s) && m.rhs.MatchString(s) }
+
+func (m orMatcher) Match(b []byte) bool       { return m.lhs.Match(b) || m.rhs.Match(b) }
+func (m orMatcher) MatchString(s string) bool { return m.lhs.MatchString(s) || m.rhs.MatchString(s) }
+
+func (m negMatcher) Match(b []byte) bool       { return !m.Matcher.Match(b) }
+func (m negMatcher) MatchString(s string) bool { return !m.Matcher.MatchString(s) }