X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2FDEVEL%2Fmathml_editor%2Fsrc%2FTPushLexer.cc;h=4b24523da5e494c01ac2202bfbea438063fbf996;hb=e290ab0a049ec2babedc3cb0ff802c430ed8ee7c;hp=b943877870c0400a8c42f94d469feab5fbe8f4f2;hpb=6a72ec9c2e81e6558a0163877129cc6227948e3e;p=helm.git

diff --git a/helm/DEVEL/mathml_editor/src/TPushLexer.cc b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
index b94387787..4b24523da 100644
--- a/helm/DEVEL/mathml_editor/src/TPushLexer.cc
+++ b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
@@ -31,7 +31,7 @@ TPushLexer::transaction(char ch, State newState)
     case '\t':
     case ' ': parser.push(TToken(TToken::SPACE, ch)); break;
     case '~': parser.push(TToken(TToken::ACTIVE, ch)); break;
-    case '%': parser.push(TToken(TToken::COMMENT)); break;
+    case '%': parser.push(TToken(TToken::COMMENT)); break;     
     default:
       if (isalpha(ch)) parser.push(TToken(TToken::LETTER, ch));
       else if (isdigit(ch)) parser.push(TToken(TToken::DIGIT, ch));
@@ -49,6 +49,7 @@ TPushLexer::push(char ch)
     case ACCEPT:
       if (ch == '\\') state = ESCAPE;
       else if (ch == '#') state = PARAMETER;
+      else if (ch == '\b') parser.push(TToken(TToken::GDELETE));
       else transaction(ch, ACCEPT);
       break;
     case ESCAPE:
@@ -57,6 +58,10 @@ TPushLexer::push(char ch)
 	  buffer.push_back(ch);
 	  state = MACRO;
 	}
+      else if (ch == '\b')
+        {
+	  state = ACCEPT;
+	}
       else
 	{
 	  parser.push(TToken(TToken::CONTROL, ch));
@@ -76,6 +81,11 @@ TPushLexer::push(char ch)
 	  buffer.erase();
 	  state = PARAMETER;
 	}
+      else if (ch == '\b')
+	{
+	  buffer.erase(buffer.length() - 1, 1);
+	  if (buffer.length() == 0) state = ESCAPE;
+	}
       else if (isalpha(ch))
 	buffer.push_back(ch);
       else
@@ -90,6 +100,7 @@ TPushLexer::push(char ch)
       if (ch == '\\') state = ESCAPE;
       else if (ch == '#') state = PARAMETER;
       else if (isspace(ch)) ;
+      else if (ch == '\b') parser.push(TToken(TToken::GDELETE));
       else transaction(ch, ACCEPT);
       break;
     case PARAMETER: