Add CircuitDiagramInfoArgs.format_real (#2569)

- Also fix the qasm UGate not having a decomposition or a correct repr

cirq/circuits/circuit.py

@@ -1797,7 +1797,7 @@ def _formatted_exponent(info: 'cirq.CircuitDiagramInfo',
                        - info.exponent) < 10**-args.precision:
                     return '({})'.format(approx_frac)
 
-            return '{{:.{}}}'.format(args.precision).format(info.exponent)
+            return args.format_real(info.exponent)
         return repr(info.exponent)
 
     # If the exponent is any other object, use its string representation.

cirq/circuits/qasm_output.py

@@ -54,24 +54,26 @@ def from_matrix(mat: np.array) -> 'QasmUGate':
             pre_phase / np.pi,
         )
 
-    def _qasm_(self, qubits: Tuple[ops.Qid, ...], args: 'cirq.QasmArgs') -> str:
+    def _qasm_(self, qubits: Tuple['cirq.Qid', ...],
+               args: 'cirq.QasmArgs') -> str:
         args.validate_version('2.0')
         return args.format(
             'u3({0:half_turns},{1:half_turns},{2:half_turns}) {3};\n',
             self.theta, self.phi, self.lmda, qubits[0])
 
     def __repr__(self) -> str:
-        return 'cirq.QasmUGate({}, {}, {})'.format(self.theta, self.phi,
-                                                   self.lmda)
-
-    def _unitary_(self) -> np.ndarray:
-        # Source: https://arxiv.org/abs/1707.03429 (equation 2)
-        operations = [
-            ops.Rz(self.phi * np.pi),
-            ops.Ry(self.theta * np.pi),
-            ops.Rz(self.lmda * np.pi),
+        return (f'cirq.circuits.qasm_output.QasmUGate('
+                f'theta={self.theta!r}, '
+                f'phi={self.phi!r}, '
+                f'lmda={self.lmda})')
+
+    def _decompose_(self, qubits):
+        q = qubits[0]
+        return [
+            ops.Rz(self.lmda * np.pi).on(q),
+            ops.Ry(self.theta * np.pi).on(q),
+            ops.Rz(self.phi * np.pi).on(q),
         ]
-        return linalg.dot(*map(protocols.unitary, operations))
 
     def _value_equality_values_(self):
         return self.lmda, self.theta, self.phi

cirq/circuits/qasm_output_test.py

@@ -27,7 +27,8 @@ def _make_qubits(n):
 
 def test_u_gate_repr():
     gate = QasmUGate(0.1, 0.2, 0.3)
-    assert repr(gate) == 'cirq.QasmUGate(0.1, 0.2, 0.3)'
+    assert repr(gate) == ('cirq.circuits.qasm_output.QasmUGate('
+                          'theta=0.1, phi=0.2, lmda=0.3)')
 
 
 def test_u_gate_eq():
@@ -51,6 +52,8 @@ def test_qasm_u_qubit_gate_unitary():
                                                     u,
                                                     atol=1e-7)
 
+    cirq.testing.assert_implements_consistent_protocols(g)
+
 
 def test_qasm_two_qubit_gate_unitary():
     u = cirq.testing.random_unitary(4)

cirq/google/optimizers/convert_to_xmon_gates_test.py

@@ -42,7 +42,7 @@ def test_avoids_infinite_cycle_when_matrix_available():
     q = cirq.GridQubit(0, 0)
     c = cirq.Circuit(OtherX().on(q), OtherOtherX().on(q))
     cirq.google.ConvertToXmonGates().optimize_circuit(c)
-    cirq.testing.assert_has_diagram(c, '(0, 0): ───PhX(1.0)───PhX(1.0)───')
+    cirq.testing.assert_has_diagram(c, '(0, 0): ───PhX(1)───PhX(1)───')
     cirq.protocols.decompose(c)
 
 

cirq/neutral_atoms/convert_to_neutral_atom_gates_test.py

@@ -59,7 +59,7 @@ def _decompose_(self, qubits):
     q = cirq.GridQubit(0, 0)
     c = cirq.Circuit(OtherX().on(q), OtherOtherX().on(q))
     cirq.neutral_atoms.ConvertToNeutralAtomGates().optimize_circuit(c)
-    cirq.testing.assert_has_diagram(c, '(0, 0): ───PhX(1.0)───PhX(1.0)───')
+    cirq.testing.assert_has_diagram(c, '(0, 0): ───PhX(1)───PhX(1)───')
 
 
 def test_avoids_decompose_fallback_when_matrix_available_two_qubit():
@@ -78,5 +78,9 @@ def _decompose_(self, qubits):
     q01 = cirq.GridQubit(0, 1)
     c = cirq.Circuit(OtherCZ().on(q00, q01), OtherOtherCZ().on(q00, q01))
     cirq.neutral_atoms.ConvertToNeutralAtomGates().optimize_circuit(c)
-    cirq.testing.assert_has_diagram(c, "(0, 0): ───@───@───\n"
-                                       "           │   │\n(0, 1): ───@───@───")
+    cirq.testing.assert_has_diagram(
+        c, """
+(0, 0): ───@───@───
+           │   │
+(0, 1): ───@───@───
+""")

cirq/ops/fsim_gate.py

@@ -169,6 +169,6 @@ def _format_rads(args: 'cirq.CircuitDiagramInfoArgs', radians: float) -> str:
     if radians == -np.pi:
         return '-' + unit
     if args.precision is not None:
-        quantity = '{{:.{}}}'.format(args.precision).format(radians / np.pi)
+        quantity = args.format_real(radians / np.pi)
         return quantity + unit
     return repr(radians)

cirq/ops/phased_iswap_gate.py

@@ -156,14 +156,9 @@ def _pauli_expansion_(self) -> value.LinearDict[str]:
             'ZZ': expansion['ZZ'],
         })
 
-    def _circuit_diagram_info_(self, args: 'protocols.CircuitDiagramInfoArgs'
-                              ) -> 'protocols.CircuitDiagramInfo':
-        if (isinstance(self._phase_exponent, (sympy.Basic, int)) or
-                args.precision is None):
-            s = 'PhISwap({})'.format(self._phase_exponent)
-        else:
-            s = 'PhISwap({{:.{}}})'.format(args.precision).format(
-                self._phase_exponent)
+    def _circuit_diagram_info_(self, args: 'cirq.CircuitDiagramInfoArgs'
+                              ) -> 'cirq.CircuitDiagramInfo':
+        s = f'PhISwap({args.format_real(self._phase_exponent)})'
         return protocols.CircuitDiagramInfo(
             wire_symbols=(s, s), exponent=self._diagram_exponent(args))
 

cirq/ops/phased_x_gate.py

@@ -146,18 +146,12 @@ def _phase_by_(self, phase_turns, qubit_index):
             phase_exponent=self._phase_exponent + phase_turns * 2,
             global_shift=self._global_shift)
 
-    def _circuit_diagram_info_(self, args: 'protocols.CircuitDiagramInfoArgs'
-                              ) -> 'protocols.CircuitDiagramInfo':
+    def _circuit_diagram_info_(self, args: 'cirq.CircuitDiagramInfoArgs'
+                              ) -> 'cirq.CircuitDiagramInfo':
         """See `cirq.SupportsCircuitDiagramInfo`."""
 
-        if (isinstance(self.phase_exponent, (sympy.Basic, int)) or
-                args.precision is None):
-            s = 'PhX({})'.format(self.phase_exponent)
-        else:
-            s = 'PhX({{:.{}}})'.format(args.precision).format(
-                self.phase_exponent)
         return protocols.CircuitDiagramInfo(
-            wire_symbols=(s,),
+            wire_symbols=(f'PhX({args.format_real(self.phase_exponent)})',),
             exponent=value.canonicalize_half_turns(self._exponent))
 
     def __str__(self):

cirq/protocols/circuit_diagram_info_protocol.py

@@ -15,6 +15,7 @@
 from typing import (Any, TYPE_CHECKING, Optional, Union, TypeVar, Dict,
                     overload, Iterable)
 
+import sympy
 from typing_extensions import Protocol
 
 from cirq import value
@@ -133,6 +134,15 @@ def __repr__(self):
                                          self.use_unicode_characters,
                                          self.precision, self.qubit_map))
 
+    def format_real(self, val: Union[sympy.Basic, int, float]) -> str:
+        if isinstance(val, sympy.Basic):
+            return str(val)
+        if val == int(val):
+            return str(int(val))
+        if self.precision is None:
+            return str(val)
+        return f'{float(val):.{self.precision}}'
+
     def copy(self):
         return self.__class__(
             known_qubits=self.known_qubits,

cirq/protocols/circuit_diagram_info_protocol_test.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import pytest
+import sympy
 
 import cirq
 
@@ -170,3 +171,21 @@ def test_circuit_diagram_info_args_repr():
                                         cirq.LineQubit(0): 5,
                                         cirq.LineQubit(1): 7
                                     }))
+
+
+def test_formal_real():
+    args = cirq.CircuitDiagramInfoArgs.UNINFORMED_DEFAULT
+    assert args.format_real(1) == '1'
+    assert args.format_real(1.1) == '1.1'
+    assert args.format_real(1.234567) == '1.23'
+    assert args.format_real(1 / 7) == '0.143'
+    assert args.format_real(sympy.Symbol('t')) == 't'
+    assert args.format_real(sympy.Symbol('t') * 2 + 1) == '2*t + 1'
+
+    args.precision = None
+    assert args.format_real(1) == '1'
+    assert args.format_real(1.1) == '1.1'
+    assert args.format_real(1.234567) == '1.234567'
+    assert args.format_real(1 / 7) == repr(1 / 7)
+    assert args.format_real(sympy.Symbol('t')) == 't'
+    assert args.format_real(sympy.Symbol('t') * 2 + 1) == '2*t + 1'