Module expr 

IR-level expression types and the flat ExprArena that stores them.

Expressions are represented as a flat vector of IrExpr nodes indexed by ExprId. This avoids deep recursive types and makes expression sharing, substitution, and serialisation straightforward.

Unlike the AST expression types in graphforge-ast, these types:

• carry no source spans (semantic-only)
• use resolved IDs (VarId, PropId) instead of raw name strings
• collapse AST-level sugar (IsNull, InList, StringOp, RegexMatch) into UnaryOp / BinaryOp variants handled uniformly by the executor

Structs

CaseArm

A single WHEN/THEN arm in a IrExpr::Case expression.

ExprArena

Flat, index-addressed storage for all IrExpr nodes in a query plan.

Enums

BinaryOpKind

The operator in a IrExpr::BinaryOp expression.

IrExpr

A single node in the ExprArena.

IrLiteral

A scalar constant value in the Graph IR.

UnaryOpKind

The operator in a IrExpr::UnaryOp expression.