Add __slots__ to dataclasses

CHANGELOG.md

@@ -19,6 +19,7 @@ Types of changes:
 - A github workflow for validating `CHANGELOG` updates in a PR ([#214](https://github.com/qBraid/pyqasm/pull/214))
 
 ### Improved / Modified
+- Added `slots=True` parameter to the data classes in `elements.py` to improve memory efficiency ([#218](https://github.com/qBraid/pyqasm/pull/218))
 
 ### Deprecated
 

src/pyqasm/elements.py

@@ -43,7 +43,7 @@ class Context(Enum):
     GATE = "gate"
 
 
-@dataclass
+@dataclass(slots=True)
 class DepthNode:
     """Base class for depth nodes."""
 
@@ -52,7 +52,7 @@ class DepthNode:
     depth: int = 0
 
 
-@dataclass
+@dataclass(slots=True)
 class QubitDepthNode(DepthNode):
     """Qubit depth node."""
 
@@ -68,7 +68,7 @@ def is_idle(self) -> bool:
         return self._total_ops() == 0
 
 
-@dataclass
+@dataclass(slots=True)
 class ClbitDepthNode(DepthNode):
     """Classical bit depth node."""
 
@@ -78,7 +78,7 @@ def is_idle(self) -> bool:
         return self.num_measurements == 0
 
 
-@dataclass
+@dataclass(slots=True)
 class Variable:  # pylint: disable=too-many-instance-attributes
     """
     Class representing an OpenQASM variable.