DPL Analysis: add parsing of expressions from strings

Author: aalkin

Framework/Core/include/Framework/BasicOps.h

@@ -10,6 +10,9 @@
 // or submit itself to any jurisdiction.
 #ifndef O2_FRAMEWORK_BASICOPS_H_
 #define O2_FRAMEWORK_BASICOPS_H_
+#include <array>
+#include <string_view>
+#include "CommonConstants/MathConstants.h"
 
 namespace o2::framework
 {
@@ -46,6 +49,61 @@ enum BasicOp : unsigned int {
   BitwiseNot,
   Conditional // 3-ar functions
 };
+
+static constexpr std::array<std::string_view, BasicOp::Conditional + 1> mapping{
+  "&&",
+  "||",
+  "+",
+  "-",
+  "/",
+  "*",
+  "&",
+  "|",
+  "^",
+  "<",
+  "<=",
+  ">",
+  ">=",
+  "==",
+  "!=",
+  "natan2",
+  "npow",
+  "nsqrt",
+  "nexp",
+  "nlog",
+  "nlog10",
+  "nsin",
+  "ncos",
+  "ntan",
+  "nasin",
+  "nacos",
+  "natan",
+  "nabs",
+  "nround",
+  "nbitwise_not",
+  "ifnode"};
+
+static constexpr std::array<std::string_view, 9> mathConstants{
+  "Almost0",
+  "Epsilon",
+  "Almost1",
+  "VeryBig",
+  "PI",
+  "TwoPI",
+  "PIHalf",
+  "PIThird",
+  "PIQuarter"};
+
+static constexpr std::array<float, 9> mathConstantsValues{
+  o2::constants::math::Almost0,
+  o2::constants::math::Epsilon,
+  o2::constants::math::Almost1,
+  o2::constants::math::VeryBig,
+  o2::constants::math::PI,
+  o2::constants::math::TwoPI,
+  o2::constants::math::PIHalf,
+  o2::constants::math::PIThird,
+  o2::constants::math::PIQuarter};
 } // namespace o2::framework
 
 #endif // O2_FRAMEWORK_BASICOPS_H_

Framework/Core/include/Framework/ExpressionHelpers.h

@@ -25,17 +25,26 @@ struct DatumSpec {
   size_t hash = 0;
   atype::type type = atype::NA;
 
-  explicit DatumSpec(size_t index, atype::type type_) : datum{index}, type{type_} {}
-  explicit DatumSpec(LiteralNode::var_t literal, atype::type type_) : datum{literal}, type{type_} {}
-  explicit DatumSpec(std::string binding, size_t hash_, atype::type type_) : datum{binding}, hash{hash_}, type{type_} {}
+  explicit constexpr DatumSpec(size_t index, atype::type type_) : datum{index}, type{type_} {}
+  explicit constexpr DatumSpec(LiteralNode::var_t literal, atype::type type_) : datum{literal}, type{type_} {}
+  explicit constexpr DatumSpec(std::string binding, size_t hash_, atype::type type_) : datum{binding}, hash{hash_}, type{type_} {}
   DatumSpec() = default;
   DatumSpec(DatumSpec const&) = default;
   DatumSpec(DatumSpec&&) = default;
   DatumSpec& operator=(DatumSpec const&) = default;
   DatumSpec& operator=(DatumSpec&&) = default;
-};
 
-bool operator==(DatumSpec const& lhs, DatumSpec const& rhs);
+  bool operator==(DatumSpec const& rhs) const
+  {
+    bool eqValue = this->datum == rhs.datum;
+    bool eqHash = true;
+    if (this->datum.index() == 3 && eqValue) {
+      eqHash = this->hash == rhs.hash;
+    }
+    bool eqType = this->type == rhs.type;
+    return eqValue && eqHash && eqType;
+  }
+};
 
 std::ostream& operator<<(std::ostream& os, DatumSpec const& spec);