Nodes

A node is an immutable, hashable dataclass that stores expression structure. Nodes are not evaluated directly — pass them to a VisitorDispatcher with matching visitors.

dynamic_expressions.nodes.Node dataclass

Base class for expression AST nodes.

Subclass this type to define new node kinds. Each node must be hashable because the dispatcher caches evaluation results keyed by the node identity.

Literal

dynamic_expressions.nodes.LiteralNode dataclass

Constant value embedded in an expression tree.

Pair with LiteralVisitor. When value is a tuple, nested Node instances are recursively evaluated during the visitation.

Attributes:

Name	Type	Description
value	Any	Constant payload, or a collection that may contain nested nodes.

Any Of

dynamic_expressions.nodes.AnyOfNode dataclass

Logical OR over a sequence of child expressions.

Evaluates to a True value if at least one child expression is truthy. Pair with AnyOfVisitor.

Attributes:

Name	Type	Description
expressions	tuple[Node, ...]	Child nodes evaluated in order until one of them is truthy.

All Of

dynamic_expressions.nodes.AllOfNode dataclass

Logical AND over a sequence of child expressions.

Evaluates to a True value only when every child expression is truthy. Pair with AllOfVisitor.

Attributes:

Name	Type	Description
expressions	tuple[Node, ...]	Child nodes evaluated in order; all must be truthy.

Unary Expression

dynamic_expressions.nodes.UnaryExpressionNode dataclass

Unary operator applied to a single child expression.

Pair with UnaryExpressionVisitor. Supported operators are listed in UnaryExpressionOperator.

Attributes:

Name	Type	Description
operator	UnaryExpressionOperator	Unary operator name, for example "not" or "-".
value	Node	Operand is evaluated before the operator is applied.

Supported operators:

Operator	Meaning
+	Unary plus (operator.pos)
-	Negation
~	Bitwise invert
abs	Absolute value
not	Logical not

Binary Expression

dynamic_expressions.nodes.BinaryExpressionNode dataclass

Binary operator applied to two child expressions.

Pair with BinaryExpressionVisitor. Supported operators are listed in BinaryExpressionOperator.

Attributes:

Name	Type	Description
operator	BinaryExpressionOperator	Binary operator name, for example "=" or "+".
left	Node	Left-hand operand.
right	Node	Right-hand operand.

Supported operators:

Operator	Meaning
=	Equality
!=	Inequality
<, <=, >, >=	Comparison
in	Membership test (left in right)
+, -, *, /, //, %, ^	Arithmetic
&, \|	Bitwise and / or
getitem	Subscript access
getattr	Dot-separated attribute path

Operand order for in

Passing the container as left and the search value as right still works but emits a DeprecationWarning. Prefer left=<search value>, right=<container>.

Coalesce

dynamic_expressions.nodes.CoalesceNode dataclass

Return the first truthy child expression.

Similar to SQL COALESCE. Pair with CoalesceVisitor.

Attributes:

Name	Type	Description
items	tuple[Node, ...]	Candidates evaluated in order; the first truthy result wins.

Match

dynamic_expressions.nodes.MatchNode dataclass

Pattern match over CaseNode branches.

Returns the value of the first case whose condition is truthy, or the optional default branch. Pair with MatchVisitor.

Attributes:

Name	Type	Description
cases	tuple[CaseNode, ...]	Branches tested in order.
default	Node | None	Fallback node is returned if no case matches.

Case

dynamic_expressions.nodes.CaseNode dataclass

Single branch inside a MatchNode.

Do not evaluate this node directly. It is handled only as part of MatchNode by MatchVisitor.

Attributes:

Name	Type	Description
expression	Node	Condition evaluated to decide whether this branch matches.
value	Node	Result returned when the condition is truthy.

From Context

dynamic_expressions.nodes.FromContextNode dataclass

Read a field from the evaluation context.

The field name may use dot notation ("user.name") to traverse nested attributes. Pair with FromContextNodeVisitor.

Attributes:

Name	Type	Description
field_name	str	Attribute path is resolved from the dispatcher context.