From 3183ca7d7ec4692ecefb2d348a0f6ceb3a403024 Mon Sep 17 00:00:00 2001
From: Ruben Dashyan <ruben.dashyan@numworks.com>
Date: Mon, 16 Sep 2019 16:34:40 +0200
Subject: [PATCH] Replace Poincare::Function unknown earlier (in Context)

---
 apps/shared/global_context.cpp   |  9 ++++++++-
 poincare/src/function.cpp        |  5 -----
 poincare/src/store.cpp           | 24 +++---------------------
 poincare/src/symbol_abstract.cpp |  3 ---
 4 files changed, 11 insertions(+), 30 deletions(-)

diff --git a/apps/shared/global_context.cpp b/apps/shared/global_context.cpp
index 6f214a5f9..418ed78c4 100644
--- a/apps/shared/global_context.cpp
+++ b/apps/shared/global_context.cpp
@@ -52,6 +52,9 @@ void GlobalContext::setExpressionForSymbolAbstract(const Expression & expression
     SetExpressionForActualSymbol(finalExpression, symbol, record);
   } else {
     assert(symbol.type() == ExpressionNode::Type::Function);
+    Expression child = symbol.childAtIndex(0);
+    assert(child.type() == ExpressionNode::Type::Symbol);
+    finalExpression = finalExpression.replaceSymbolWithExpression(static_cast<Symbol&>(child), Symbol::Builder(UCodePointUnknownX));
     SetExpressionForFunction(finalExpression, symbol, record);
   }
 }
@@ -79,7 +82,11 @@ const Expression GlobalContext::ExpressionForFunction(const SymbolAbstract & sym
   }
   /* An function record value has metadata before the expression. To get the
    * expression, use the function record handle. */
-  return ContinuousFunction(r).expressionClone();
+  Expression e = ContinuousFunction(r).expressionClone();
+  if (!e.isUninitialized()) {
+    e = e.replaceSymbolWithExpression(Symbol::Builder(UCodePointUnknownX), symbol.childAtIndex(0));
+  }
+  return e;
 }
 
 Ion::Storage::Record::ErrorStatus GlobalContext::SetExpressionForActualSymbol(const Expression & expression, const SymbolAbstract & symbol, Ion::Storage::Record previousRecord) {
diff --git a/poincare/src/function.cpp b/poincare/src/function.cpp
index 14b9e3109..c5bdf51b3 100644
--- a/poincare/src/function.cpp
+++ b/poincare/src/function.cpp
@@ -101,10 +101,6 @@ Expression Function::replaceSymbolWithExpression(const SymbolAbstract & symbol,
   childAtIndex(0).replaceSymbolWithExpression(symbol, expression);
   if (symbol.type() == ExpressionNode::Type::Function && strcmp(name(), symbol.name()) == 0) {
     Expression value = expression.clone();
-    // Replace the unknown in the new expression by the function's child
-    Symbol xSymbol = Symbol::Builder(UCodePointUnknownX);
-    Expression xValue = childAtIndex(0);
-    value = value.replaceSymbolWithExpression(xSymbol, xValue);
     Expression p = parent();
     if (!p.isUninitialized() && p.node()->childAtIndexNeedsUserParentheses(value, p.indexOfChild(*this))) {
       value = Parenthesis::Builder(value);
@@ -143,7 +139,6 @@ Expression Function::deepReplaceReplaceableSymbols(Context * context, bool * did
   {
     return replaceWithUndefinedInPlace();
   }
-  e.replaceSymbolWithExpression(Symbol::Builder(UCodePointUnknownX), childAtIndex(0));
   replaceWithInPlace(e);
   *didReplace = true;
   return e;
diff --git a/poincare/src/store.cpp b/poincare/src/store.cpp
index 4e894bc85..1f26a4669 100644
--- a/poincare/src/store.cpp
+++ b/poincare/src/store.cpp
@@ -67,31 +67,13 @@ Expression Store::shallowReduce(ExpressionNode::ReductionContext reductionContex
 }
 
 Expression Store::storeValueForSymbol(Context * context, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit angleUnit) const {
-  Expression finalValue;
-  if (symbol().type() == ExpressionNode::Type::Function) {
-    // In tata + 2 ->f(tata), replace tata with xUnknown symbol
-    assert(symbol().childAtIndex(0).type() == ExpressionNode::Type::Symbol);
-    Expression userDefinedUnknown = symbol().childAtIndex(0);
-    Symbol xUnknown = Symbol::Builder(UCodePointUnknownX);
-    finalValue = childAtIndex(0).replaceSymbolWithExpression(static_cast<Symbol &>(userDefinedUnknown), xUnknown);
-  } else {
-    assert(symbol().type() == ExpressionNode::Type::Symbol);
-    finalValue = childAtIndex(0);
-  }
-  assert(!finalValue.isUninitialized());
-  context->setExpressionForSymbolAbstract(finalValue, symbol());
-  Expression storedExpression = context->expressionForSymbolAbstract(symbol(), true);
+  assert(!value().isUninitialized());
+  context->setExpressionForSymbolAbstract(value(), symbol());
+  Expression storedExpression = context->expressionForSymbolAbstract(symbol(), false);
 
   if (storedExpression.isUninitialized()) {
     return Undefined::Builder();
   }
-  if (symbol().type() == ExpressionNode::Type::Function) {
-    // Replace the xUnknown symbol with the variable initially used
-    assert(symbol().childAtIndex(0).type() == ExpressionNode::Type::Symbol);
-    Expression userDefinedUnknown = symbol().childAtIndex(0);
-    Symbol xUnknown = Symbol::Builder(UCodePointUnknownX);
-    storedExpression = storedExpression.replaceSymbolWithExpression(xUnknown, static_cast<Symbol &>(userDefinedUnknown));
-  }
   return storedExpression;
 }
 
diff --git a/poincare/src/symbol_abstract.cpp b/poincare/src/symbol_abstract.cpp
index 244e0e86d..a6754aeec 100644
--- a/poincare/src/symbol_abstract.cpp
+++ b/poincare/src/symbol_abstract.cpp
@@ -64,9 +64,6 @@ Expression SymbolAbstract::Expand(const SymbolAbstract & symbol, Context * conte
   /* Replace all the symbols iteratively. This prevents a memory failure when
    * symbols are defined circularly. */
   e = Expression::ExpressionWithoutSymbols(e, context);
-  if (!e.isUninitialized() && isFunction) {
-    e = e.replaceSymbolWithExpression(Symbol::Builder(UCodePointUnknownX), symbol.childAtIndex(0));
-  }
   return e;
 }