SyntaxTree.h

Go to the documentation of this file.

 
#pragma once
 
#ifndef _SYNTAXTREE_H_
#define _SYNTAXTREE_H_
 
#include "../Circuit/Factory.h"
#include "SimpleOps.h"
 
namespace qasm {
struct AddGateExpr : public AbstractSyntaxTree {
  struct result {
    typedef QoperationStatement type;
  };
 
  QoperationStatement operator()(
      const UopType &uop,
      const std::unordered_map<std::string, IndexedId> &qreg_map,
      const std::unordered_map<std::string, StatementType> &opaqueGates,
      const std::unordered_map<std::string, StatementType> &definedGates,
      const std::unordered_map<std::string, double> &variables = {}) const {
    StatementType stmt;
    stmt.opType = QoperationStatement::OperationType::Uop;
 
    if (std::holds_alternative<UGateCallType>(uop)) {
      const auto &gate = std::get<UGateCallType>(uop);
      const std::vector<Expression> &params = boost::fusion::at_c<0>(gate);
      const ArgumentType &arg = boost::fusion::at_c<1>(gate);
 
      stmt.gateType = Circuits::QuantumGateType::kUGateType;
 
      for (const auto &p : params)
        stmt.parameters.push_back(p.Eval(variables));
 
      stmt.qubits = ParseQubits(arg, qreg_map);
    } else if (std::holds_alternative<CXGateCallType>(uop)) {
      const auto &gate = std::get<CXGateCallType>(uop);
 
      stmt.gateType = Circuits::QuantumGateType::kCXGateType;
 
      // two arguments
      const ArgumentType &arg1 = boost::fusion::at_c<0>(gate);
      const ArgumentType &arg2 = boost::fusion::at_c<1>(gate);
 
      const std::vector<int> qubits1 = ParseQubits(arg1, qreg_map);
      const std::vector<int> qubits2 = ParseQubits(arg2, qreg_map);
 
      // four cases
      if (qubits1.size() == 1 && qubits2.size() == 1) {
        // cx q1[i], q2[j]
        stmt.qubits.push_back(qubits1[0]);
        stmt.qubits.push_back(qubits2[0]);
      } else if (qubits1.size() == 1 && qubits2.size() > 1) {
        // cx q1[i], q2
        for (const auto &q2 : qubits2) {
          if (q2 == qubits1[0])
            throw std::invalid_argument(
                "Control and target qubits cannot be the same for CX gate");
          stmt.qubits.push_back(qubits1[0]);
          stmt.qubits.push_back(q2);
        }
      } else if (qubits1.size() > 1 && qubits2.size() == 1) {
        // cx q[], q[j]
        for (const auto &q1 : qubits1) {
          if (q1 == qubits2[0])
            throw std::invalid_argument(
                "Control and target qubits cannot be the same for CX gate");
          stmt.qubits.push_back(q1);
          stmt.qubits.push_back(qubits2[0]);
        }
      } else if (qubits1.size() == qubits2.size()) {
        // cx q1, q2
        for (size_t i = 0; i < qubits1.size(); ++i) {
          if (qubits1[i] == qubits2[i])
            throw std::invalid_argument(
                "Control and target qubits cannot be the same for CX gate");
          stmt.qubits.push_back(qubits1[i]);
          stmt.qubits.push_back(qubits2[i]);
        }
      } else
        throw std::invalid_argument(
            "Mismatched qubits sizes for CX gate arguments");
    } else if (std::holds_alternative<GatecallType>(uop)) {
      const auto &gateCall = std::get<GatecallType>(uop);
      // can be either simple or with expressions
      if (std::holds_alternative<SimpleGatecallType>(gateCall)) {
        // gate without parameters
        const auto &gate = std::get<SimpleGatecallType>(gateCall);
        const std::string &gateName = boost::fusion::at_c<0>(gate);
        std::string gateNameLower = gateName;
        std::transform(gateNameLower.begin(), gateNameLower.end(),
                       gateNameLower.begin(), ::tolower);
 
        const MixedListType &args = boost::fusion::at_c<1>(gate);
 
        const auto it = definedGates.find(gateName);
        if (it == definedGates.end()) {
          if (!IsSuppportedGate(gateNameLower))
            throw std::invalid_argument(
                "Unsupported gate without parameters: " + gateName);
 
          stmt.gateType = GetGateType(gateNameLower);
          const int expectedNrQubits = GateNrQubits(stmt.gateType);
          if (args.size() != expectedNrQubits)
            throw std::invalid_argument(
                "Gate " + gateName + " requires exactly " +
                std::to_string(expectedNrQubits) + " qubits");
        } else {
          // defined gate, check if the number of qubits match
          const StatementType &definedGateStmt = it->second;
          const int expectedNrQubits =
              static_cast<int>(definedGateStmt.qubitsDecl.size());
          if (args.size() != expectedNrQubits)
            throw std::invalid_argument(
                "Defined gate " + gateName + " requires exactly " +
                std::to_string(expectedNrQubits) + " qubits");
          if (definedGateStmt.parameters.size() != 0)
            throw std::invalid_argument(
                "Defined gate " + gateName +
                " requires parameters, but none were provided");
 
          stmt.comment = gateName;
 
          // copy the gate definition here, as it might be redefined later
          // (actually not yet supported)
          stmt.qubitsDecl = definedGateStmt.qubitsDecl;
          stmt.declOps = definedGateStmt.declOps;
        }
 
        // first, check the qubits
        int qubitsCounter = 1;
 
        std::vector<std::vector<int>> allQubits(args.size());
        for (int i = 0; i < static_cast<int>(args.size()); ++i) {
          const ArgumentType &arg = args[i];
          std::vector<int> qubits = ParseQubits(arg, qreg_map);
 
          if (qubits.size() != 1) {
            if (qubitsCounter == 1)
              qubitsCounter = static_cast<int>(qubits.size());
            else if (qubitsCounter != static_cast<int>(qubits.size()))
              throw std::invalid_argument(
                  "Mismatched qubits sizes for gate arguments");
          }
 
          allQubits[i] = std::move(qubits);
        }
 
        // now set them
        for (int i = 0; i < qubitsCounter; ++i) {
          for (const auto &qlist : allQubits) {
            if (qlist.size() == 1)
              stmt.qubits.push_back(qlist[0]);
            else
              stmt.qubits.push_back(qlist[i]);
          }
        }
      } else if (std::holds_alternative<ExpGatecallType>(gateCall)) {
        // gate with parameters
        const auto &gate = std::get<ExpGatecallType>(gateCall);
        const std::string &gateName = boost::fusion::at_c<0>(gate);
        std::string gateNameLower = gateName;
        std::transform(gateNameLower.begin(), gateNameLower.end(),
                       gateNameLower.begin(), ::tolower);
 
        const std::vector<Expression> &params = boost::fusion::at_c<1>(gate);
        const MixedListType &args = boost::fusion::at_c<2>(gate);
 
        for (const auto &p : params)
          stmt.parameters.push_back(p.Eval(variables));
 
        const auto it = definedGates.find(gateName);
        if (it == definedGates.end()) {
          if (IsSuppportedGate(gateNameLower)) {
            if (params.empty())
              throw std::invalid_argument("Gate " + gateName +
                                          " requires parameters");
            else if (params.size() == 1) {
              if (!IsSuppportedOneParamGate(gateNameLower))
                throw std::invalid_argument(
                    "This gate does not allow one parameter: " + gateName);
            } else if (params.size() > 1) {
              if (!IsSuppportedMultipleParamsGate(gateNameLower))
                throw std::invalid_argument(
                    "This gate does not allow multiple parameters: " +
                    gateName);
 
              if (params.size() > 4)
                throw std::invalid_argument("Too many parameters for gate: " +
                                            gateName);
            }
 
            stmt.gateType = GetGateType(gateNameLower);
            const int expectedNrQubits = GateNrQubits(stmt.gateType);
            if (args.size() != expectedNrQubits)
              throw std::invalid_argument(
                  "Gate " + gateName + " requires exactly " +
                  std::to_string(expectedNrQubits) + " qubits");
 
            if (gateNameLower == "u1") {
              const double lambda = stmt.parameters[0];
              stmt.parameters[0] = 0.0; // theta
              stmt.parameters.push_back(0.);
              stmt.parameters.push_back(lambda);
            } else if (gateNameLower == "u2") {
              const double phi = stmt.parameters[0];
              const double lambda = stmt.parameters[1];
 
              stmt.parameters[0] = M_PI / 2.0; // theta
              stmt.parameters[1] = phi;
              stmt.parameters.push_back(lambda);
            } else if (gateNameLower == "cu1") {
              const double lambda = stmt.parameters[0];
              stmt.parameters[0] = 0.0; // theta
              stmt.parameters.push_back(0.);
              stmt.parameters.push_back(lambda);
            } else if (gateNameLower == "cu2") {
              const double phi = stmt.parameters[0];
              const double lambda = stmt.parameters[1];
 
              stmt.parameters[0] = M_PI / 2.0; // theta
              stmt.parameters[1] = phi;
              stmt.parameters.push_back(lambda);
            }
          } else if (gateNameLower == "u1") {
            stmt.gateType = Circuits::QuantumGateType::kUGateType;
 
            if (stmt.parameters.size() != 1)
              throw std::invalid_argument(
                  "Gate u1 requires exactly one parameter");
 
            const double lambda = stmt.parameters[0];
            stmt.parameters[0] = 0.0; // theta
            stmt.parameters.push_back(0.);
            stmt.parameters.push_back(lambda);
 
            if (args.size() != 1)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 1 qubit");
          } else if (gateNameLower == "u2") {
            stmt.gateType = Circuits::QuantumGateType::kUGateType;
 
            if (stmt.parameters.size() != 2)
              throw std::invalid_argument("Gate u2 requires two parameters");
 
            const double phi = stmt.parameters[0];
            const double lambda = stmt.parameters[1];
 
            stmt.parameters[0] = M_PI / 2.0; // theta
            stmt.parameters[1] = phi;
            stmt.parameters.push_back(lambda);
 
            if (args.size() != 1)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 1 qubit");
          } else if (gateNameLower == "u3") {
            stmt.gateType = Circuits::QuantumGateType::kUGateType;
 
            if (stmt.parameters.size() != 3)
              throw std::invalid_argument("Gate u3 requires three parameters");
            // nothing to do, u3 already has the correct parameters
 
            if (args.size() != 1)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 1 qubit");
          } else if (gateNameLower == "cu1") {
            stmt.gateType = Circuits::QuantumGateType::kCUGateType;
 
            if (stmt.parameters.size() != 1)
              throw std::invalid_argument(
                  "Gate cu1 requires exactly one parameter");
 
            const double lambda = stmt.parameters[0];
            stmt.parameters[0] = 0.0; // theta
            stmt.parameters.push_back(0.);
            stmt.parameters.push_back(lambda);
 
            if (args.size() != 2)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 2 qubits");
          } else if (gateNameLower == "cu2") {
            stmt.gateType = Circuits::QuantumGateType::kCUGateType;
 
            if (stmt.parameters.size() != 2)
              throw std::invalid_argument("Gate cu2 requires two parameters");
 
            const double phi = stmt.parameters[0];
            const double lambda = stmt.parameters[1];
 
            stmt.parameters[0] = M_PI / 2.0; // theta
            stmt.parameters[1] = phi;
            stmt.parameters.push_back(lambda);
 
            if (args.size() != 2)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 2 qubits");
          } else if (gateNameLower == "cu3") {
            stmt.gateType = Circuits::QuantumGateType::kCUGateType;
 
            if (stmt.parameters.size() != 3)
              throw std::invalid_argument("Gate cu3 requires three parameters");
            // nothing to do, cu3 already has the correct parameters
 
            if (args.size() != 2)
              throw std::invalid_argument("Gate " + gateName +
                                          " requires exactly 2 qubits");
          }
        } else {
          // defined gate, check if the number of parameters and qubits match
          const StatementType &definedGateStmt = it->second;
          const int expectedNrQubits =
              static_cast<int>(definedGateStmt.qubitsDecl.size());
          if (args.size() != expectedNrQubits)
            throw std::invalid_argument(
                "Defined gate " + gateName + " requires exactly " +
                std::to_string(expectedNrQubits) + " qubits");
 
          if (definedGateStmt.paramsDecl.size() != stmt.parameters.size())
            throw std::invalid_argument(
                "Defined gate " + gateName + " requires a different number (" +
                std::to_string(definedGateStmt.paramsDecl.size()) +
                ") of parameters than " +
                std::to_string(stmt.parameters.size()));
 
          stmt.comment = gateName;
 
          // copy the gate definition here, as it might be redefined later
          stmt.paramsDecl = definedGateStmt.paramsDecl;
          stmt.qubitsDecl = definedGateStmt.qubitsDecl;
          stmt.declOps = definedGateStmt.declOps;
        }
 
        // first, check the qubits
        int qubitsCounter = 1;
 
        std::vector<std::vector<int>> allQubits(args.size());
        for (int i = 0; i < static_cast<int>(args.size()); ++i) {
          const ArgumentType &arg = args[i];
          std::vector<int> qubits = ParseQubits(arg, qreg_map);
 
          if (qubits.size() != 1) {
            if (qubitsCounter == 1)
              qubitsCounter = static_cast<int>(qubits.size());
            else if (qubitsCounter != static_cast<int>(qubits.size()))
              throw std::invalid_argument(
                  "Mismatched qubits sizes for gate arguments");
          }
 
          allQubits[i] = std::move(qubits);
        }
 
        // now set them
        for (int i = 0; i < qubitsCounter; ++i) {
          for (const auto &qlist : allQubits) {
            if (qlist.size() == 1)
              stmt.qubits.push_back(qlist[0]);
            else
              stmt.qubits.push_back(qlist[i]);
          }
        }
      }
    }
 
    return stmt;
  }
 
  static std::vector<int>
  ParseQubits(const ArgumentType &arg,
              const std::unordered_map<std::string, IndexedId> &qreg_map) {
    std::vector<int> qubits;
    // there are two possibilities here, either it's an indexed id or a simple
    // id
    if (std::holds_alternative<IndexedId>(arg)) {
      const IndexedId &indexedId = std::get<IndexedId>(arg);
      auto it = qreg_map.find(indexedId.id);
      if (it != qreg_map.end()) {
        int base = it->second.base;
        qubits.push_back(base + indexedId.index);
      }
    } else if (std::holds_alternative<std::string>(arg)) {
      const std::string &id = std::get<std::string>(arg);
      auto it = qreg_map.find(id);
      if (it != qreg_map.end()) {
        int base = it->second.base;
        int size = static_cast<int>(std::round(it->second.Eval()));
        for (int i = 0; i < size; ++i)
          qubits.push_back(base + i);
      }
    }
 
    return qubits;
  }
 
  static bool IsSuppportedNoParamGate(const std::string &gateName) {
    return allowedNoParamGates.find(gateName) != allowedNoParamGates.end();
  }
 
  static bool IsSuppportedOneParamGate(const std::string &gateName) {
    return allowedOneParamGates.find(gateName) != allowedOneParamGates.end();
  }
 
  static bool IsSuppportedMultipleParamsGate(const std::string &gateName) {
    return allowedMultipleParamsGates.find(gateName) !=
           allowedMultipleParamsGates.end();
  }
 
  static bool IsSuppportedGate(const std::string &gateName) {
    return allowedNoParamGates.find(gateName) != allowedNoParamGates.end() ||
           allowedOneParamGates.find(gateName) != allowedOneParamGates.end() ||
           allowedMultipleParamsGates.find(gateName) !=
               allowedMultipleParamsGates.end();
  }
 
  Circuits::QuantumGateType GetGateType(const std::string &gateN) const {
    std::string gateName = gateN;
    std::transform(gateName.begin(), gateName.end(), gateName.begin(),
                   ::tolower);
 
    if (gateName == "x")
      return Circuits::QuantumGateType::kXGateType;
    else if (gateName == "y")
      return Circuits::QuantumGateType::kYGateType;
    else if (gateName == "z")
      return Circuits::QuantumGateType::kZGateType;
    else if (gateName == "h")
      return Circuits::QuantumGateType::kHadamardGateType;
    else if (gateName == "s")
      return Circuits::QuantumGateType::kSGateType;
    else if (gateName == "sdg" || gateName == "sxdag")
      return Circuits::QuantumGateType::kSdgGateType;
    else if (gateName == "t")
      return Circuits::QuantumGateType::kTGateType;
    else if (gateName == "tdg" || gateName == "tdag")
      return Circuits::QuantumGateType::kTdgGateType;
    else if (gateName == "sx")
      return Circuits::QuantumGateType::kSxGateType;
    else if (gateName == "sxdg" || gateName == "sxdag")
      return Circuits::QuantumGateType::kSxDagGateType;
    else if (gateName == "k")
      return Circuits::QuantumGateType::kKGateType;
    else if (gateName == "swap")
      return Circuits::QuantumGateType::kSwapGateType;
    else if (gateName == "cx")
      return Circuits::QuantumGateType::kCXGateType;
    else if (gateName == "cy")
      return Circuits::QuantumGateType::kCYGateType;
    else if (gateName == "cz")
      return Circuits::QuantumGateType::kCZGateType;
    else if (gateName == "ch")
      return Circuits::QuantumGateType::kCHGateType;
    else if (gateName == "csx")
      return Circuits::QuantumGateType::kCSxGateType;
    else if (gateName == "csxdg" || gateName == "csxdag")
      return Circuits::QuantumGateType::kCSxDagGateType;
    else if (gateName == "cswap")
      return Circuits::QuantumGateType::kCSwapGateType;
    else if (gateName == "ccx")
      return Circuits::QuantumGateType::kCCXGateType;
    else if (gateName == "p")
      return Circuits::QuantumGateType::kPhaseGateType;
    else if (gateName == "rx")
      return Circuits::QuantumGateType::kRxGateType;
    else if (gateName == "ry")
      return Circuits::QuantumGateType::kRyGateType;
    else if (gateName == "rz")
      return Circuits::QuantumGateType::kRzGateType;
    else if (gateName == "cp")
      return Circuits::QuantumGateType::kCPGateType;
    else if (gateName == "crx")
      return Circuits::QuantumGateType::kCRxGateType;
    else if (gateName == "cry")
      return Circuits::QuantumGateType::kCRyGateType;
    else if (gateName == "crz")
      return Circuits::QuantumGateType::kCRzGateType;
    else if (gateName == "u" || gateName == "u3" || gateName == "u1")
      return Circuits::QuantumGateType::kUGateType;
    else if (gateName == "cu" || gateName == "cu3" || gateName == "cu1")
      return Circuits::QuantumGateType::kCUGateType;
 
    return Circuits::QuantumGateType::kNone; // this will be returnd also for
                                             // 'id'
  }
 
  static int GateNrQubits(Circuits::QuantumGateType gateType) {
    const int gateT = static_cast<int>(gateType);
 
    if (gateT < static_cast<int>(Circuits::QuantumGateType::kSwapGateType))
      return 1;
    else if (gateT <
             static_cast<int>(Circuits::QuantumGateType::kCSwapGateType))
      return 2;
    else if (gateT <= static_cast<int>(Circuits::QuantumGateType::kCCXGateType))
      return 3;
 
    return 0;
  }
 
private:
  static inline std::unordered_set<std::string> allowedNoParamGates = {
      "x",    "y",   "z",     "h",      "s",     "sdg",  "sdag", "t",  "tdg",
      "tdag", "sx",  "sxdg",  "sxdag",  "k",     "swap", "cx",   "cy", "cz",
      "ch",   "csx", "csxdg", "csxdag", "cswap", "ccx",  "id"};
  static inline std::unordered_set<std::string> allowedOneParamGates = {
      "p", "rx", "ry", "rz", "cp", "crx", "cry", "crz", "u1", "cu1"};
  static inline std::unordered_set<std::string> allowedMultipleParamsGates = {
      "u", "u3", "cu1", "cu3"}; // max 4
};
 
phx::function<AddGateExpr> AddGate;
 
struct AddCondQopExpr : public AbstractSyntaxTree {
  struct result {
    typedef QoperationStatement type;
  };
 
  QoperationStatement
  operator()(CondOpType &condOp,
             const std::unordered_map<std::string, IndexedId> &qreg_map,
             const std::unordered_map<std::string, IndexedId> &creg_map,
             const std::unordered_map<std::string, StatementType> &opaqueGates,
             const std::unordered_map<std::string, StatementType> &definedGates)
      const {
    StatementType stmt;
 
    const std::string &condId = boost::fusion::at_c<0>(condOp);
    int condVal = boost::fusion::at_c<1>(condOp);
    const QoperationStatement &op = boost::fusion::at_c<2>(condOp);
 
    stmt = op;
 
    stmt.opType = QoperationStatement::OperationType::CondUop;
    stmt.condValue = condVal;
 
    if (creg_map.find(condId) == creg_map.end())
      throw std::invalid_argument("Condition register not found: " + condId);
    else {
      const IndexedId &condCreg = creg_map.at(condId);
 
      for (int c = 0; c < condCreg.Eval(); ++c)
        stmt.cbits.push_back(condCreg.base + c);
    }
 
    return stmt;
  }
};
 
phx::function<AddCondQopExpr> AddCondQop;
 
struct Program {
  double version = 2.0;
  std::vector<StatementType> statements;
  std::vector<std::string> comments;
  std::vector<std::string> includes;
 
  Program(const ProgramType &program = {}) {
    comments = boost::fusion::at_c<0>(program);
    version = boost::fusion::at_c<1>(program);
    includes = boost::fusion::at_c<2>(program);
    statements = boost::fusion::at_c<3>(program);
  }
 
  void clear() {
    comments.clear();
    includes.clear();
    statements.clear();
    version = 2.0;
  }
 
  template <typename Time = Types::time_type>
  std::shared_ptr<Circuits::Circuit<Time>> ToCircuit(
      std::unordered_map<std::string, StatementType> &opaqueGates,
      std::unordered_map<std::string, StatementType> &definedGates) const {
    auto circuit = std::make_shared<Circuits::Circuit<Time>>();
 
    for (const auto &stmt : statements)
      AddToCircuit(circuit, stmt, opaqueGates, definedGates);
 
    return circuit;
  }
 
  template <typename Time = Types::time_type>
  static void
  AddToCircuit(const std::shared_ptr<Circuits::Circuit<Time>> &circuit,
               const StatementType &stmt,
               std::unordered_map<std::string, StatementType> &opaqueGates,
               std::unordered_map<std::string, StatementType> &definedGates) {
    switch (stmt.opType) {
    case QoperationStatement::OperationType::Measurement: {
      if (stmt.qubits.size() != stmt.cbits.size())
        throw std::invalid_argument("Measurement operation: number of qubits "
                                    "and classical bits do not match.");
 
      std::vector<std::pair<Types::qubit_t, size_t>> qs;
      for (size_t i = 0; i < stmt.qubits.size(); ++i)
        qs.push_back({static_cast<Types::qubit_t>(stmt.qubits[i]),
                      static_cast<size_t>(stmt.cbits[i])});
 
      auto measureOp = Circuits::CircuitFactory<Time>::CreateMeasurement(qs);
      circuit->AddOperation(measureOp);
    } break;
    case QoperationStatement::OperationType::Reset: {
      Types::qubits_vector qubits(stmt.qubits.begin(), stmt.qubits.end());
      auto resetOp = Circuits::CircuitFactory<Time>::CreateReset(qubits);
      circuit->AddOperation(resetOp);
    } break;
 
    case QoperationStatement::OperationType::Uop: {
      if (stmt.gateType != Circuits::QuantumGateType::kNone) {
        // can add more than one gate here depending on what's in qubits
        double param1 = stmt.parameters.size() > 0 ? stmt.parameters[0] : 0;
        double param2 = stmt.parameters.size() > 1 ? stmt.parameters[1] : 0;
        double param3 = stmt.parameters.size() > 2 ? stmt.parameters[2] : 0;
        double param4 = stmt.parameters.size() > 3 ? stmt.parameters[3] : 0;
 
        int nrQubits = AddGateExpr::GateNrQubits(stmt.gateType);
        if (stmt.qubits.size() % nrQubits != 0)
          throw std::invalid_argument("Uop operation: number of qubits does "
                                      "not match the gate requirements.");
 
        for (int pos = 0; pos < static_cast<int>(stmt.qubits.size());
             pos += nrQubits) {
          Types::qubits_vector gateQubits;
          for (int q = 0; q < nrQubits; ++q)
            gateQubits.push_back(
                static_cast<Types::qubit_t>(stmt.qubits[pos + q]));
 
          auto gateOp = Circuits::CircuitFactory<Time>::CreateGate(
              stmt.gateType, gateQubits[0], nrQubits > 1 ? gateQubits[1] : 0,
              nrQubits > 2 ? gateQubits[2] : 0, param1, param2, param3, param4);
 
          circuit->AddOperation(gateOp);
        }
      } else {
        // it's a defined gate, check further and implement
        // will add several gates to the circuit
        if (stmt.paramsDecl.size() != stmt.parameters.size())
          throw std::invalid_argument("Uop operation: number of parameters do "
                                      "not match the declaration.");
 
        std::unordered_map<std::string, double> variables;
 
        for (size_t i = 0; i < stmt.paramsDecl.size(); ++i)
          variables[stmt.paramsDecl[i]] = stmt.parameters[i];
 
        int nrQubits = static_cast<int>(stmt.qubitsDecl.size());
        if (stmt.qubits.size() % nrQubits != 0)
          throw std::invalid_argument("Defined Uop operation: number of qubits "
                                      "does not match the gate requirements.");
 
        for (int pos = 0; pos < static_cast<int>(stmt.qubits.size());
             pos += nrQubits) {
          std::unordered_map<std::string, IndexedId> qubitMap;
          for (int q = 0; q < nrQubits; ++q) {
            IndexedId id;
            id.id = stmt.qubitsDecl[q];
            id.base = stmt.qubits[pos + q];
            id.index = 1;
            qubitMap[id.id] = id;
          }
 
          // now walk over all gates in declOps and add them to the circuit
          AddGateExpr addGate;
          for (const auto &op : stmt.declOps) {
            StatementType gateStmt =
                addGate(op, qubitMap, opaqueGates, definedGates, variables);
 
            AddToCircuit(circuit, gateStmt, opaqueGates, definedGates);
          }
        }
      }
    } break;
    case QoperationStatement::OperationType::CondUop: {
      unsigned long long int condValue =
          static_cast<unsigned long long int>(stmt.condValue);
 
      if (stmt.gateType != Circuits::QuantumGateType::kNone) {
        // can add more than one gate here depending on what's in qubits
        double param1 = stmt.parameters.size() > 0 ? stmt.parameters[0] : 0;
        double param2 = stmt.parameters.size() > 1 ? stmt.parameters[1] : 0;
        double param3 = stmt.parameters.size() > 2 ? stmt.parameters[2] : 0;
        double param4 = stmt.parameters.size() > 3 ? stmt.parameters[3] : 0;
 
        int nrQubits = AddGateExpr::GateNrQubits(stmt.gateType);
        if (stmt.qubits.size() % nrQubits != 0)
          throw std::invalid_argument("Uop operation: number of qubits does "
                                      "not match the gate requirements.");
 
        std::vector<size_t> ind;
        std::vector<bool> condBits;
 
        for (size_t i = 0; i < stmt.cbits.size(); ++i) {
          ind.push_back(static_cast<size_t>(stmt.cbits[i]));
          condBits.push_back((condValue & 1) == 1);
          condValue >>= 1;
        }
 
        const auto condition =
            Circuits::CircuitFactory<Time>::CreateEqualCondition(ind, condBits);
 
        for (int pos = 0; pos < static_cast<int>(stmt.qubits.size());
             pos += nrQubits) {
          Types::qubits_vector gateQubits;
          for (int q = 0; q < nrQubits; ++q)
            gateQubits.push_back(
                static_cast<Types::qubit_t>(stmt.qubits[pos + q]));
 
          auto gateOp = Circuits::CircuitFactory<Time>::CreateGate(
              stmt.gateType, gateQubits[0], nrQubits > 1 ? gateQubits[1] : 0,
              nrQubits > 2 ? gateQubits[2] : 0, param1, param2, param3, param4);
 
          auto condOp = Circuits::CircuitFactory<Time>::CreateConditionalGate(
              gateOp, condition);
          circuit->AddOperation(condOp);
        }
      } else {
        // it's a defined gate, check further and implement
        // will add several gates to the circuit
        if (stmt.paramsDecl.size() != stmt.parameters.size())
          throw std::invalid_argument("Uop operation: number of parameters do "
                                      "not match the declaration.");
 
        std::unordered_map<std::string, double> variables;
 
        for (size_t i = 0; i < stmt.paramsDecl.size(); ++i)
          variables[stmt.paramsDecl[i]] = stmt.parameters[i];
 
        int nrQubits = static_cast<int>(stmt.qubitsDecl.size());
        if (stmt.qubits.size() % nrQubits != 0)
          throw std::invalid_argument("Defined Uop operation: number of qubits "
                                      "does not match the gate requirements.");
 
        for (int pos = 0; pos < static_cast<int>(stmt.qubits.size());
             pos += nrQubits) {
          std::unordered_map<std::string, IndexedId> qubitMap;
          for (int q = 0; q < nrQubits; ++q) {
            IndexedId id;
            id.id = stmt.qubitsDecl[q];
            id.base = stmt.qubits[pos + q];
            id.index = 1;
            qubitMap[id.id] = id;
          }
 
          // now walk over all gates in declOps and add them to the circuit
          AddGateExpr addGate;
          for (const auto &op : stmt.declOps) {
            StatementType gateStmt =
                addGate(op, qubitMap, opaqueGates, definedGates, variables);
 
            // make each of them conditioned on the original condition
            gateStmt.opType = QoperationStatement::OperationType::CondUop;
            gateStmt.condValue = static_cast<int>(condValue);
            gateStmt.cbits = stmt.cbits;
 
            AddToCircuit(circuit, gateStmt, opaqueGates, definedGates);
          }
        }
      }
    } break;
    case QoperationStatement::OperationType::Comment:
    case QoperationStatement::OperationType::Declaration:
    case QoperationStatement::OperationType::Barrier:
    case QoperationStatement::OperationType::OpaqueDecl:
    case QoperationStatement::OperationType::
        GateDecl: // do not generate anything here, it's already handled when
                  // the gate is called
    default:
      // those are ignored
      break;
    }
  }
};
 
} // namespace qasm
 
#endif // !_SYNTAXTREE_H_