add different match types to search

Sources/dpk-cli/ExactMatcher.swift

@@ -0,0 +1,36 @@
+/*
+ * darwin-apk © 2024 Gay Pizza Specifications
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import Foundation
+import ArgumentParser
+
+struct ExactMatcher: PatternMatcher {
+  private let _matches: [String]
+  private let _ignoreCase: Bool
+
+  init(patterns: [String], ignoreCase: Bool) throws(ArgumentParser.ExitCode) {
+    self._matches = patterns
+    self._ignoreCase = ignoreCase
+  }
+
+  func match(_ field: String) -> Bool {
+    if self._ignoreCase {
+      for match in self._matches {
+        // May want to use localizedCaseInsensitiveCompare
+        //  if localised descriptions ever become involved
+        if field.caseInsensitiveCompare(match) == .orderedSame {
+          return true
+        }
+      }
+    } else {
+      for match in self._matches {
+        if field == match {
+          return true
+        }
+      }
+    }
+    return false
+  }
+}