From: Mike D. Lowis <mike@mdlowis.com>
Date: Wed, 27 Jun 2012 20:02:51 +0000 (-0400)
Subject: Updated lexer class to support combining lexers together
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=e2b262f1c501ba87725fb00efaa97ad386b59ae9;p=archive%2Fparse-utils.git

Updated lexer class to support combining lexers together
---

diff --git a/tests/test_experimental.cpp b/tests/test_experimental.cpp
index 25d7b99..79bb20b 100644
--- a/tests/test_experimental.cpp
+++ b/tests/test_experimental.cpp
@@ -49,14 +49,21 @@ class CharBuffer : public IBuffer
         }
 };
 
+//-----------------------------------------------------------------------------
+// Lexer Class
+//-----------------------------------------------------------------------------
 class Lexer
 {
+    protected:
+        Lexer* lex_sibling;
+        Lexer* lex_child;
     public:
-        Lexer()
+        // Construction/Destruction
+        Lexer() : lex_sibling(0), lex_child(0)
         {
         }
 
-        Lexer(Lexer& lxr)
+        Lexer(const Lexer& lxr) : lex_sibling(0), lex_child(0)
         {
         }
 
@@ -64,38 +71,66 @@ class Lexer
         {
         }
 
-        Lexer* clone()
+        // Accessors
+        Lexer* sibling()
+        {
+            return lex_sibling;
+        }
+
+        void sibling(Lexer* lxr)
+        {
+            lex_sibling = lxr;
+        }
+
+        Lexer* child()
+        {
+            return lex_child;
+        }
+
+        void child(Lexer* lxr)
+        {
+            lex_sibling = lxr;
+        }
+
+        // Action methods
+        Lexer* clone() const
         {
             return new Lexer(*this);
         }
 
-        Token operator() (CharBuffer& input)
+        void addSibling(Lexer* lxr)
         {
-            return Token();
         }
 
-        Lexer& operator= (const Lexer& rhs)
+        void addChild(Lexer* lxr)
         {
-            return *this;
+        }
+
+        // Operators
+        Token operator() (CharBuffer& input)
+        {
+            std::cout << this << " ";
+            if( NULL != sibling() )
+            {
+                (*sibling())( input );
+            }
+            std::cout << std::endl;
+            return Token();
         }
 
         Lexer& operator+ (const Lexer& rhs)
         {
+            addSibling( rhs.clone() );
             return *this;
         }
 
         Lexer& operator| (const Lexer& rhs)
         {
+            addChild( rhs.clone() );
             return *this;
         }
 };
 
-class Parser
-{
-    public:
-        //AST* operator() (CharBuffer& input) = 0;
-};
-
 //-----------------------------------------------------------------------------
 // Begin Unit Tests
 //-----------------------------------------------------------------------------
@@ -108,9 +143,7 @@ namespace {
         std::ifstream file;
         file.open( "input.txt" );
         CharBuffer input( file );
-        Lexer lexer;
-        lexer = (Lexer() + Lexer())
-              | (Lexer() + Lexer() + Lexer());
+        Lexer& lexer = (Lexer() + Lexer() + Lexer());
         lexer( input );
     }
 }