Added a SkipString() method to the parser helper; began work in implementing a configuration file parser

git-svn-id: file:///srv/devel/repo-conversion/nusu@296 d2e56fa2-650e-0410-a79f-9358c0239efd

Source/Parsing/ParserHelper.Test.cs

@@ -158,6 +158,74 @@ namespace Nuclex.Support.Parsing {
       Assert.AreEqual(5, index);
     }
 
+		/// <summary>
+		///   Verifies that trying to skip text as if it was an integer skips nothing
+		/// </summary>
+		[Test]
+		public void SkippingTextAsIntegerReturnsFalse() {
+			int index = 0;
+			Assert.IsFalse(ParserHelper.SkipInteger("hello", ref index));
+			Assert.AreEqual(0, index);
+		}
+
+		/// <summary>Ensures that the SkipIntegers() method can handle null strings</summary>
+		[Test]
+		public void CanSkipStringInNullString() {
+			int index = 0;
+			Assert.IsFalse(ParserHelper.SkipString((string)null, ref index));
+			Assert.AreEqual(0, index);
+		}
+
+		/// <summary>Ensures that the SkipNumbers() method can handle empty strings</summary>
+		[Test]
+		public void CanSkipStringInEmptyString() {
+			int index = 0;
+			Assert.IsFalse(ParserHelper.SkipString(string.Empty, ref index));
+			Assert.AreEqual(0, index);
+		}
+
+		/// <summary>Verifies that a string consisting of a single word can be skipped</summary>
+		[Test]
+		public void SingleWordStringsCanBeSkipped() {
+			int index = 0;
+			Assert.IsTrue(ParserHelper.SkipString("hello", ref index));
+			Assert.AreEqual(5, index);
+		}
+
+		/// <summary>
+		///   Verifies that a space character is not skipped over when skipping a string
+		/// </summary>
+		[Test]
+		public void SpaceTerminatesUnquotedStrings() {
+			int index = 0;
+			Assert.IsTrue(ParserHelper.SkipString("hello world", ref index));
+			Assert.AreEqual(5, index);
+		}
+
+		/// <summary>Verifies that a string in quotes continues until the closing quote</summary>
+		[Test]
+		public void QuotedStringsCanBeSkipped() {
+			int index = 0;
+			Assert.IsTrue(ParserHelper.SkipString("\"This is a test\"", ref index));
+			Assert.AreEqual(16, index);
+		}
+
+		/// <summary>Verifies that a string in quotes continues until the closing quote</summary>
+		[Test]
+		public void QuotedStringsStopAtClosingQuote() {
+			int index = 0;
+			Assert.IsTrue(ParserHelper.SkipString("\"This is a test\" but this not.", ref index));
+			Assert.AreEqual(16, index);
+		}
+
+		/// <summary>Verifies that a string in quotes continues until the closing quote</summary>
+		[Test]
+		public void QuotedStringRequiresClosingQuote() {
+			int index = 0;
+			Assert.IsFalse(ParserHelper.SkipString("\"This is missing the closing quote", ref index));
+			Assert.AreEqual(0, index);
+		}
+
   }
 
 } // namespace Nuclex.Support.Parsing

Source/Parsing/ParserHelper.cs

@@ -64,6 +64,10 @@ namespace Nuclex.Support.Parsing {
     /// <summary>Advances the index to the next character that isn't numeric</summary>
     /// <param name="text">String which is being indexed</param>
     /// <param name="index">Index that will be advanced</param>
+    /// <remarks>
+    ///   This skips only numeric characters, but not complete numbers -- if the number
+    ///   begins with a minus or plus sign, for example, this function will not skip it.
+    /// </remarks>
     public static void SkipNumbers(string text, ref int index) {
       if(text == null) {
         return;
@@ -115,6 +119,41 @@ namespace Nuclex.Support.Parsing {
       return true;
     }
 
+    /// <summary>Skips a string appearing in the input text</summary>
+    /// <param name="text">Text in which a string will be skipped</param>
+    /// <param name="index">Index at which the string begins</param>
+    /// <returns>True if a string was found and skipped, otherwise false</returns>
+    public static bool SkipString(string text, ref int index) {
+      if(text == null) {
+        return false;
+      }
+
+      int length = text.Length;
+      if(index >= length) {
+        return false;
+      }
+
+      // If the string begins with an opening quote, look for the closing quote
+      if(text[index] == '"') {
+
+        int endIndex = text.IndexOf('"', index + 1);
+        if(endIndex == -1) {
+          return false;
+        }
+
+        index = endIndex + 1;
+        return true;
+
+      } else { // Normal strings end with the first whitespace
+
+        int startIndex = index;
+        SkipNonSpaces(text, ref index);
+
+        return (index != startIndex);
+
+      }
+    }
+
   }
 
 } // namespace Nuclex.Support.Parsing