Add y gate based on ry gate.

pyzx/circuit/gates.py

@@ -465,6 +465,15 @@ def to_graph(self, g, q_mapper, c_mapper):
     def tcount(self):
         return 1 if self.phase.denominator > 2 else 0
 
+class Y(YPhase):
+    name = 'Y'
+    qasm_name = 'y'
+    qc_name = 'Y'
+    quipper_name = 'Y'
+    print_phase = False
+    def __init__(self, target: int) -> None:
+        super().__init__(target, phase = Fraction(1,1))
+
 class NOT(XPhase):
     name = 'NOT'
     qasm_name = 'x'
@@ -990,6 +999,7 @@ def to_graph(self, g, q_mapper, c_mapper):
 
 qasm_gate_table: Dict[str, Type[Gate]] = {
     "x": NOT,
+    "y": Y,
     "z": Z,
     "s": S,
     "t": T,

pyzx/circuit/qasmparser.py

@@ -169,7 +169,7 @@ def parse_command(self, c: str, registers: Dict[str,Tuple[int,int]]) -> List[Gat
                 for g in circ.gates:
                     gates.append(g.reposition(argset))
                 continue
-            if name in ('x', 'z', 's', 't', 'h', 'sdg', 'tdg'):
+            if name in ('x', 'y', 'z', 's', 't', 'h', 'sdg', 'tdg'):
                 if name in ('sdg', 'tdg'):
                     g = qasm_gate_table[name](argset[0],adjoint=True) # type: ignore # mypy can't handle -
                 else: g = qasm_gate_table[name](argset[0]) # type: ignore # - Gate subclasses with different numbers of parameters