Update qasm.py (#335)

* Update qasm.py
* Update ci_chemistry_psi4.yml (psi4 --> conda-forge channel)
* Update README.md

.github/workflows/ci_chemistry_psi4.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: [3.9]
 
     steps:
     - uses: actions/checkout@v2
@@ -50,7 +50,7 @@ jobs:
         source $HOME/.bashrc
         source $CONDABASE/bin/activate
         conda activate test_psi4
-        conda install psi4 python=3.8 -c psi4 
+        conda install psi4 python=3.9 -c conda-forge
         python -m pip install --upgrade pip
         python -m pip install -r requirements.txt
         python -m pip install -e .

README.md

@@ -14,7 +14,7 @@ Tequila can execute the underlying quantum expectation values on state of the ar
 - [talks and slides](https://kottmanj.github.io/talks_and_material/)  
 
 # Installation
-Recommended Python version is 3.8-3.9.   
+Recommended Python version is 3.9 - 3.10.   
 Tequila supports linux, osx and windows. However, not all optional dependencies are supported on windows.  
 
 ## Install from PyPi
@@ -267,7 +267,7 @@ Currently supported
 ### [Psi4](https://github.com/psi4/psi4).
 In a conda environment this can be installed with
 ```bash
-conda install psi4 -c psi4
+conda install psi4 -c conda-forge
 ```
 Here is a small [tutorial](https://nbviewer.org/github/tequilahub/tequila-tutorials/blob/main/chemistry/ChemistryModule.ipynb) that illustrates the usage.
 

src/tequila/circuit/qasm.py

@@ -313,19 +313,33 @@ def parse_command(command: str, custom_gates_map: Dict[str, QCircuit], qregister
         return apply_custom_gate(custom_circuit=custom_circuit, qregisters_values=qregisters_values)
 
     if name in ("x", "y", "z", "h", "cx", "cy", "cz", "ch"):
-        return QCircuit.wrap_gate(gates.impl.QGateImpl(name=(name[1] if name[0] == 'c' else name).upper(),
-                                            control=get_qregister(args[0], qregisters) if name[0] == 'c' else None,
-                                            target=get_qregister(args[1 if name[0] == 'c' else 0], qregisters)))
+        target = get_qregister(args[0], qregisters)
+        control = None
+        if name[0].lower() == 'c':
+            control = get_qregister(args[0], qregisters)
+            target = get_qregister(args[1], qregisters)
+            name = name[1]
+        G = getattr(gates, name.upper())
+        return G(control=control, target=target)
+
     if name in ("ccx", "ccy", "ccz"):
-        return QCircuit.wrap_gate(gates.impl.QGateImpl(name=name.upper()[2],
-                                            control=[get_qregister(args[0], qregisters), get_qregister(args[1], qregisters)],
-                                            target=get_qregister(args[2], qregisters)))
+        G = getattr(gates, name[2].upper())
+        control = [get_qregister(args[0], qregisters), get_qregister(args[1], qregisters)]
+        target = get_qregister(args[2], qregisters)
+        return G(control=control, target=target)
+
     if name.startswith("rx(") or name.startswith("ry(") or name.startswith("rz(") or \
         name.startswith("crx(") or name.startswith("cry(") or name.startswith("crz("):
-        return QCircuit.wrap_gate(gates.impl.RotationGateImpl(axis=name[2 if name[0] == 'c' else 1],
-                                                   angle=get_angle(name)[0],
-                                                   control=get_qregister(args[0], qregisters) if name[0] == 'c' else None,
-                                                   target=get_qregister(args[1 if name[0] == 'c' else 0], qregisters)))
+        angle = get_angle(name)[0]
+        i = name.find('(')
+        name = name[0:i]
+        name = name.upper()
+        name = [x for x in name]
+        name[-1] = name[-1].lower()
+        name = "".join(name)
+        G = getattr(gates, name)
+        return G(angle=angle,control=get_qregister(args[0], qregisters) if name[0] == 'C' else None,target=get_qregister(args[1 if name[0] == 'C' else 0], qregisters))
+
     if name.startswith("U("):
         angles = get_angle(name)
         return gates.U(theta=angles[0], phi=angles[1], lambd=angles[2],