X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2FDEVEL%2Fmathml_editor%2Fsrc%2FTPushLexer.cc;fp=helm%2FDEVEL%2Fmathml_editor%2Fsrc%2FTPushLexer.cc;h=b943877870c0400a8c42f94d469feab5fbe8f4f2;hb=30060cffed61b88fe53e4d6386b606050d6dfda0;hp=0000000000000000000000000000000000000000;hpb=e6927665462cbbace76cff1b17d4f8badcb44eda;p=helm.git

diff --git a/helm/DEVEL/mathml_editor/src/TPushLexer.cc b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
new file mode 100644
index 000000000..b94387787
--- /dev/null
+++ b/helm/DEVEL/mathml_editor/src/TPushLexer.cc
@@ -0,0 +1,117 @@
+
+#include "TToken.hh"
+#include "TPushLexer.hh"
+#include "APushParser.hh"
+
+TPushLexer::TPushLexer(APushParser& p) : APushLexer(p)
+{
+  state = ACCEPT;
+}
+
+void
+TPushLexer::reset()
+{
+  buffer.erase();
+  state = ACCEPT;
+}
+
+void
+TPushLexer::transaction(char ch, State newState)
+{
+  switch (ch)
+    {
+    case '{': parser.push(TToken(TToken::BEGIN)); break;
+    case '}': parser.push(TToken(TToken::END)); break;
+    case '$': parser.push(TToken(TToken::SHIFT)); break;
+    case '&': parser.push(TToken(TToken::ALIGN)); break;
+    case '\n':
+    case '\r': parser.push(TToken(TToken::EOL, ch)); break;
+    case '^': parser.push(TToken(TToken::SUPERSCRIPT)); break;
+    case '_': parser.push(TToken(TToken::SUBSCRIPT)); break;
+    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;
+    default:
+      if (isalpha(ch)) parser.push(TToken(TToken::LETTER, ch));
+      else if (isdigit(ch)) parser.push(TToken(TToken::DIGIT, ch));
+      else parser.push(TToken(TToken::OTHER, ch));
+      break;
+    }
+  state = newState;
+}
+
+void
+TPushLexer::push(char ch)
+{
+  switch (state)
+    {
+    case ACCEPT:
+      if (ch == '\\') state = ESCAPE;
+      else if (ch == '#') state = PARAMETER;
+      else transaction(ch, ACCEPT);
+      break;
+    case ESCAPE:
+      if (isalpha(ch))
+	{
+	  buffer.push_back(ch);
+	  state = MACRO;
+	}
+      else
+	{
+	  parser.push(TToken(TToken::CONTROL, ch));
+	  state = ACCEPT;
+	}
+      break;
+    case MACRO:
+      if (ch == '\\')
+	{
+	  parser.push(TToken(TToken::CONTROL, buffer));
+	  buffer.erase();
+	  state = ESCAPE;
+	}
+      else if (ch == '#')
+	{
+	  parser.push(TToken(TToken::CONTROL, buffer));
+	  buffer.erase();
+	  state = PARAMETER;
+	}
+      else if (isalpha(ch))
+	buffer.push_back(ch);
+      else
+	{
+	  parser.push(TToken(TToken::CONTROL, buffer));
+	  buffer.erase();
+	  if (isspace(ch)) state = IGNORE_SPACE;
+	  else transaction(ch, ACCEPT);
+	}
+      break;
+    case IGNORE_SPACE:
+      if (ch == '\\') state = ESCAPE;
+      else if (ch == '#') state = PARAMETER;
+      else if (isspace(ch)) ;
+      else transaction(ch, ACCEPT);
+      break;
+    case PARAMETER:
+      parser.push(TToken(TToken::PARAMETER, ch));
+      state = ACCEPT;
+      break;
+    default:
+      assert(0);
+      break;
+    }
+
+  switch (state)
+    {
+    case ESCAPE: parser.setCursor("\\"); break;
+    case MACRO: parser.setCursor("\\" + buffer); break;
+    case PARAMETER: parser.setCursor("#"); break;
+    default: parser.setCursor("?"); break;
+    }
+}
+
+bool
+TPushLexer::error() const
+{
+  return false;
+}