Flee

Parsing/StringElement.cs

@@ -0,0 +1,64 @@
+namespace Flee.Parsing
+{
+    /**
+     * A regular expression string element. This element only matches
+     * an exact string. Once created, the string element is immutable.
+     */
+    internal class StringElement : Element
+    {
+        private readonly string _value;
+        public StringElement(char c)
+            : this(c.ToString())
+        {
+        }
+
+        public StringElement(string str)
+        {
+            _value = str;
+        }
+
+        public string GetString()
+        {
+            return _value;
+        }
+
+        public override object Clone()
+        {
+            return this;
+        }
+
+        public override int Match(Matcher m,
+                                  ReaderBuffer buffer,
+                                  int start,
+                                  int skip)
+        {
+            if (skip != 0)
+            {
+                return -1;
+            }
+            for (int i = 0; i < _value.Length; i++)
+            {
+                var c = buffer.Peek(start + i);
+                if (c < 0)
+                {
+                    m.SetReadEndOfString();
+                    return -1;
+                }
+                if (m.IsCaseInsensitive())
+                {
+                    c = (int)Char.ToLower((char)c);
+                }
+                if (c != (int)_value[i])
+                {
+                    return -1;
+                }
+            }
+            return _value.Length;
+        }
+
+        public override void PrintTo(TextWriter output, string indent)
+        {
+            output.WriteLine(indent + "'" + _value + "'");
+        }
+    }
+}