From 900506f6c6034b754bf05e1c647fc5ca6ee23203 Mon Sep 17 00:00:00 2001
From: nietras <nietras@users.noreply.github.com>
Date: Thu, 11 Jul 2024 15:41:38 +0200
Subject: [PATCH] Add SepReaderHeader.TryIndexOf (#146)

---
 README.md                           | 1 +
 src/Sep.Test/SepReaderHeaderTest.cs | 7 +++++++
 src/Sep/SepReaderHeader.cs          | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/README.md b/README.md
index dbc3a5e..8779250 100644
--- a/README.md
+++ b/README.md
@@ -1687,6 +1687,7 @@ namespace nietras.SeparatedValues
         public void IndicesOf(System.ReadOnlySpan<string> colNames, System.Span<int> colIndices) { }
         public System.Collections.Generic.IReadOnlyList<string> NamesStartingWith(string prefix, System.StringComparison comparison = 4) { }
         public override string ToString() { }
+        public bool TryIndexOf(string colName, out int colIndex) { }
     }
     public readonly struct SepReaderOptions : System.IEquatable<nietras.SeparatedValues.SepReaderOptions>
     {
diff --git a/src/Sep.Test/SepReaderHeaderTest.cs b/src/Sep.Test/SepReaderHeaderTest.cs
index f5c4090..9af102a 100644
--- a/src/Sep.Test/SepReaderHeaderTest.cs
+++ b/src/Sep.Test/SepReaderHeaderTest.cs
@@ -45,6 +45,13 @@ public void SepReaderHeaderTest_NotEmpty()
         AreEqual([0, 2], header.IndicesOf((ReadOnlySpan<string>)["A", "C"]));
         AreEqual([2, 0], header.IndicesOf((IReadOnlyList<string>)["C", "A"]));
 
+        var tryTrue = header.TryIndexOf("B", out var tryTrueIndex);
+        Assert.IsTrue(tryTrue);
+        Assert.AreEqual(1, tryTrueIndex);
+        var tryFalse = header.TryIndexOf("XX", out var tryFalseIndex);
+        Assert.IsFalse(tryFalse);
+        Assert.AreEqual(0, tryFalseIndex);
+
         var actualIndices = new int[2];
         header.IndicesOf((ReadOnlySpan<string>)["A", "C"], actualIndices);
         AreEqual([0, 2], actualIndices);
diff --git a/src/Sep/SepReaderHeader.cs b/src/Sep/SepReaderHeader.cs
index 0d77cf4..0fd597c 100644
--- a/src/Sep/SepReaderHeader.cs
+++ b/src/Sep/SepReaderHeader.cs
@@ -41,6 +41,8 @@ internal static SepReaderHeader Parse(Sep sep, string line, IEqualityComparer<st
 
     public int IndexOf(string colName) => _colNameToIndex[colName];
 
+    public bool TryIndexOf(string colName, out int colIndex) => _colNameToIndex.TryGetValue(colName, out colIndex);
+
     public IReadOnlyList<string> NamesStartingWith(string prefix, StringComparison comparison = StringComparison.Ordinal)
     {
         var colNames = new List<string>();