[Sequences] Changing the name of CacheContext to SequenceCacheContext

Change-Id: If2d542748f6f7b2363d6c1443f88c058475945eb

apps/shared/sequence_cache_context.cpp

@@ -0,0 +1,80 @@
+#include "sequence_cache_context.h"
+#include "sequence.h"
+#include "sequence_store.h"
+#include "poincare_helpers.h"
+#include <poincare/serialization_helper.h>
+#include <poincare/addition.h>
+#include <poincare/rational.h>
+#include <cmath>
+
+using namespace Poincare;
+
+namespace Shared {
+
+template<typename T>
+SequenceCacheContext<T>::SequenceCacheContext(SequenceContext * sequenceContext) :
+  ContextWithParent(sequenceContext),
+  m_values{{NAN, NAN},{NAN, NAN},{NAN,NAN}},
+  m_sequenceContext(sequenceContext)
+{
+}
+
+template<typename T>
+const Expression SequenceCacheContext<T>::expressionForSymbolAbstract(const Poincare::SymbolAbstract & symbol, bool clone, float unknownSymbolValue ) {
+  // [u|v|w](n(+1)?)
+  if (symbol.type() == ExpressionNode::Type::Sequence) {
+    int index = nameIndexForSymbol(const_cast<Symbol &>(static_cast<const Symbol &>(symbol)));
+    Expression rank = symbol.childAtIndex(0).clone();
+    if (rank.isIdenticalTo(Symbol::Builder(UCodePointUnknown))) {
+      return Float<T>::Builder(m_values[index][0]);
+    } if (rank.isIdenticalTo(Addition::Builder(Symbol::Builder(UCodePointUnknown), Rational::Builder(1)))) {
+      return Float<T>::Builder(m_values[index][1]);
+    }
+    Ion::Storage::Record record = m_sequenceContext->sequenceStore()->recordAtIndex(index);
+    if (!record.isNull()) {
+      Sequence * seq = m_sequenceContext->sequenceStore()->modelForRecord(record);
+      rank.replaceSymbolWithExpression(Symbol::Builder(UCodePointUnknown), Float<T>::Builder(m_nValue));
+      T n = PoincareHelpers::ApproximateToScalar<T>(rank, this);
+      // In case the sequence referenced is not defined or if the rank is not an int, return NAN
+      if (seq->fullName() != nullptr) {
+        if (std::floor(n) == n) {
+          Expression sequenceExpression = seq->expressionReduced(this);
+          if (seq->hasValidExpression(this)) {
+            return Float<T>::Builder(seq->valueAtRank<T>(n, m_sequenceContext));
+          }
+        }
+      }
+    } else {
+      return Float<T>::Builder(NAN);
+    }
+  }
+  return ContextWithParent::expressionForSymbolAbstract(symbol, clone);
+}
+
+template<typename T>
+void SequenceCacheContext<T>::setValueForSymbol(T value, const Poincare::Symbol & symbol) {
+  m_values[nameIndexForSymbol(symbol)][rankIndexForSymbol(symbol)] = value;
+}
+
+template<typename T>
+int SequenceCacheContext<T>::nameIndexForSymbol(const Poincare::Symbol & symbol) {
+  assert(symbol.name()[0] >= 'u' && symbol.name()[0] <= 'w'); //  [u|v|w]
+  char name = symbol.name()[0];
+  assert(name >= SequenceStore::k_sequenceNames[0][0] && name <= SequenceStore::k_sequenceNames[MaxNumberOfSequences-1][0]); // u, v or w
+  return name - 'u';
+}
+
+template<typename T>
+int SequenceCacheContext<T>::rankIndexForSymbol(const Poincare::Symbol & symbol) {
+  assert(strcmp(symbol.name()+1, "(n)") == 0 || strcmp(symbol.name()+1, "(n+1)") == 0); // u(n) or u(n+1)
+  if (symbol.name()[3] == ')') { // (n)
+    return 0;
+  }
+  // (n+1)
+  return 1;
+}
+
+template class SequenceCacheContext<float>;
+template class SequenceCacheContext<double>;
+
+}