starmath: Make DoSubSup() return SmNode by taking another node

as an argument, not from the top of the stack.
Because no token belongs to groups TG::Limit and TG::Power at
the same time, we can replace TokenInGroup() with direct comparison
with each group.

Change-Id: I44882ab40f59c4de1c0e2cbbdc354e43de926ab1
Reviewed-on: https://gerrit.libreoffice.org/35500
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Takeshi Abe <tabe@fixedpoint.jp>

2 files changed, 25 insertions, 24 deletions

diff --git a/starmath/inc/parse.hxx b/starmath/inc/parse.hxx
index b4dc0a133206..1b96c159ed70 100644
--- a/starmath/inc/parse.hxx
+++ b/starmath/inc/parse.hxx
@@ -67,14 +67,14 @@ class SmParser
     void    DoRelation();
     void    DoSum();
     void    DoProduct();
-    void    DoSubSup(TG nActiveGroup);
+    SmNode *DoSubSup(TG nActiveGroup, SmNode *pGivenNode);
     void    DoOpSubSup();
     void    DoPower();
     SmBlankNode *DoBlank();
     SmNode *DoTerm(bool bGroupNumberIdent);
     SmNode *DoEscape();
     SmOperNode *DoOperator();
-    void    DoOper();
+    SmNode *DoOper();
     SmStructureNode *DoUnOper();
     void    DoAlign();
     SmStructureNode *DoFontAttribut();
diff --git a/starmath/source/parse.cxx b/starmath/source/parse.cxx
index a4c390d87867..b9f7fde0c746 100644
--- a/starmath/source/parse.cxx
+++ b/starmath/source/parse.cxx
@@ -1171,14 +1171,10 @@ void SmParser::DoProduct()
     }
 }
 
-void SmParser::DoSubSup(TG nActiveGroup)
+SmNode *SmParser::DoSubSup(TG nActiveGroup, SmNode *pGivenNode)
 {
-    OSL_ENSURE(nActiveGroup == TG::Power  ||  nActiveGroup == TG::Limit,
-               "Sm: wrong token group");
-
-    if (!TokenInGroup(nActiveGroup))
-        // already finish
-        return;
+    assert(nActiveGroup == TG::Power || nActiveGroup == TG::Limit);
+    assert(m_aCurToken.nGroup == nActiveGroup);
 
     std::unique_ptr<SmSubSupNode> pNode(new SmSubSupNode(m_aCurToken));
     //! Of course 'm_aCurToken' is just the first sub-/supscript token.
@@ -1190,7 +1186,7 @@ void SmParser::DoSubSup(TG nActiveGroup)
 
     // initialize subnodes array
     SmNodeArray aSubNodes(1 + SUBSUP_NUM_ENTRIES, nullptr);
-    aSubNodes[0] = popOrZero(m_aNodeStack);
+    aSubNodes[0] = pGivenNode;
 
     // process all sub-/supscripts
     int  nIndex = 0;
@@ -1232,26 +1228,31 @@ void SmParser::DoSubSup(TG nActiveGroup)
     }
 
     pNode->SetSubNodes(aSubNodes);
-    m_aNodeStack.push_front(std::move(pNode));
+    return pNode.release();
 }
 
 void SmParser::DoOpSubSup()
 {
-    // push operator symbol
-    m_aNodeStack.push_front(o3tl::make_unique<SmMathSymbolNode>(m_aCurToken));
+    // get operator symbol
+    auto pNode = o3tl::make_unique<SmMathSymbolNode>(m_aCurToken);
     // skip operator token
     NextToken();
     // get sub- supscripts if any
-    if (TokenInGroup(TG::Power))
-        DoSubSup(TG::Power);
+    if (m_aCurToken.nGroup == TG::Power)
+        m_aNodeStack.emplace_front(DoSubSup(TG::Power, pNode.release()));
+    else
+        m_aNodeStack.push_front(std::move(pNode));
 }
 
 void SmParser::DoPower()
 {
     // get body for sub- supscripts on top of stack
-    m_aNodeStack.emplace_front(DoTerm(false));
+    SmNode *pNode = DoTerm(false);
 
-    DoSubSup(TG::Power);
+    if (m_aCurToken.nGroup == TG::Power)
+        m_aNodeStack.emplace_front(DoSubSup(TG::Power, pNode));
+    else
+        m_aNodeStack.emplace_front(pNode);
 }
 
 SmBlankNode *SmParser::DoBlank()
@@ -1544,12 +1545,12 @@ SmOperNode *SmParser::DoOperator()
 
     auto pSNode = o3tl::make_unique<SmOperNode>(m_aCurToken);
 
-    // put operator on top of stack
-    DoOper();
+    // get operator
+    SmNode *pOperator = DoOper();
 
-    if (TokenInGroup(TG::Limit) || TokenInGroup(TG::Power))
-        DoSubSup(m_aCurToken.nGroup);
-    SmNode *pOperator = popOrZero(m_aNodeStack);
+    if ( m_aCurToken.nGroup == TG::Limit ||
+         m_aCurToken.nGroup == TG::Power )
+        pOperator = DoSubSup(m_aCurToken.nGroup, pOperator);
 
     // get argument
     DoPower();
@@ -1558,7 +1559,7 @@ SmOperNode *SmParser::DoOperator()
     return pSNode.release();
 }
 
-void SmParser::DoOper()
+SmNode *SmParser::DoOper()
 {
     SmTokenType  eType (m_aCurToken.eType);
     std::unique_ptr<SmNode> pNode;
@@ -1607,9 +1608,9 @@ void SmParser::DoOper()
         default :
             assert(false && "unknown case");
     }
-    m_aNodeStack.push_front(std::move(pNode));
 
     NextToken();
+    return pNode.release();
 }
 
 SmStructureNode *SmParser::DoUnOper()