Lexer: Added minimal lexer that currently only identifies words

src/Lexer.h

@@ -0,0 +1,59 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2013 - 2015, Paul Beckingham, Federico Hernandez.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// http://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDED_LEXER
+#define INCLUDED_LEXER
+
+#include <string>
+#include <map>
+#include <vector>
+#include <cstddef>
+
+class Lexer
+{
+public:
+  enum class Type { word };
+
+  Lexer (const std::string&);
+  bool token (std::string&, Lexer::Type&);
+
+  // Static helpers.
+  static bool isWhitespace                   (int);
+  static bool isSingleCharOperator           (int);
+
+  // Stream Classifiers.
+  bool isEOS          () const;
+  bool isWord         (std::string&, Lexer::Type&);
+
+private:
+  std::string _text;
+  std::size_t _cursor;
+  std::size_t _eos;
+};
+
+#endif
+
+////////////////////////////////////////////////////////////////////////////////