feat: Added GetKeyReferences and GetKeys.

Author: kekyo

NamingFormatter/FormatKeyReference.cs

@@ -0,0 +1,104 @@
+/////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// NamingFormatter - String format library with key-valued replacer.
+// Copyright (c) 2016-2019 Kouji Matsui (@kekyo2)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+/////////////////////////////////////////////////////////////////////////////////////////////////
+
+using System;
+
+namespace NamingFormatter
+{
+    /// <summary>
+    /// Represents a named placeholder reference contained in a format string.
+    /// </summary>
+    /// <remarks>
+    /// The reference preserves the original key path, such as <c>commit.Author.Name</c>,
+    /// and exposes the root key for callers that need to resolve only the first segment.
+    /// </remarks>
+    public readonly struct FormatKeyReference
+    {
+        private readonly string keyPath;
+        private readonly string rootKey;
+
+        /// <summary>
+        /// Initializes a new instance.
+        /// </summary>
+        /// <param name="keyPath">The parsed key path.</param>
+        /// <param name="placeholderStartIndex">The placeholder start index in the original format string.</param>
+        /// <param name="placeholderLength">The placeholder length in the original format string.</param>
+        public FormatKeyReference(
+            string keyPath,
+            int placeholderStartIndex,
+            int placeholderLength)
+        {
+            if (keyPath == null)
+            {
+                throw new ArgumentNullException(nameof(keyPath));
+            }
+            if (placeholderStartIndex < 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(placeholderStartIndex));
+            }
+            if (placeholderLength < 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(placeholderLength));
+            }
+
+            this.keyPath = keyPath;
+            this.rootKey =
+                (keyPath.IndexOf('.') is var dotIndex) && (dotIndex >= 0) ?
+                    keyPath.Substring(0, dotIndex) :
+                    keyPath;
+            this.PlaceholderStartIndex = placeholderStartIndex;
+            this.PlaceholderLength = placeholderLength;
+        }
+
+        /// <summary>
+        /// Gets the full key path.
+        /// </summary>
+        public string KeyPath =>
+            this.keyPath;
+
+        /// <summary>
+        /// Gets the first segment of the key path.
+        /// </summary>
+        public string RootKey =>
+            this.rootKey;
+
+        /// <summary>
+        /// Gets the placeholder start index in the original format string.
+        /// </summary>
+        public int PlaceholderStartIndex
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the placeholder length in the original format string.
+        /// </summary>
+        public int PlaceholderLength
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Returns the key path.
+        /// </summary>
+        /// <returns>The key path.</returns>
+        public override string ToString() =>
+            this.KeyPath;
+    }
+}