Added shortcut for arrows when doing start math formulas

Added shortcut of <- and -> for entering leftarrow and right arrow. This greatly speeds up entering formula when taking notes.

Change-Id: Ib84e330b15aab4e8068870df63d808d8ce90b9fe
Reviewed-on: https://gerrit.libreoffice.org/15011Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

starmath/source/parse.cxx

@@ -557,6 +557,16 @@ void SmParser::NextToken()
 
                             rnEndPos = nRealStart + 2;
                         }
+                        else if (m_aBufferString.match("<-", nRealStart))
+                        {
+                            m_aCurToken.eType    = TLEFTARROW;
+                            m_aCurToken.cMathChar = MS_LEFTARROW;
+                            m_aCurToken.nGroup       = TGSTANDALONE;
+                            m_aCurToken.nLevel       = 5;
+                            m_aCurToken.aText = "<-";
+
+                            rnEndPos = nRealStart + 2;
+                        }
                         else if (m_aBufferString.match("<>", nRealStart))
                         {
                             m_aCurToken.eType    = TNEQ;
@@ -854,6 +864,16 @@ void SmParser::NextToken()
 
                             rnEndPos = nRealStart + 2;
                         }
+                        else if (m_aBufferString.match("->", nRealStart))
+                        {
+                            m_aCurToken.eType    = TRIGHTARROW;
+                            m_aCurToken.cMathChar = MS_RIGHTARROW;
+                            m_aCurToken.nGroup       = TGSTANDALONE;
+                            m_aCurToken.nLevel       = 5;
+                            m_aCurToken.aText = "->";
+
+                            rnEndPos = nRealStart + 2;
+                        }
                         else
                         {
                             m_aCurToken.eType    = TMINUS;