Struct ExpressionEval 

pub struct ExpressionEval { /* private fields */ }

Lightweight expression evaluator using direct VM execution.

ExpressionEval provides the simplest possible API for expression evaluation:

1. Compile the expression once with new()
2. Evaluate rows with eval() or eval_bool()

This is the recommended replacement for CompiledEvaluator when you have a single expression to evaluate repeatedly.

Example

// Compile once
let eval = ExpressionEval::compile(&expr, &columns)?;

// Evaluate many rows
for row in rows {
    let value = eval.eval(&row)?;
    // or for boolean: let matches = eval.eval_bool(&row);
}

Implementations

impl ExpressionEval

pub fn compile(expr: &Expression, columns: &[String]) -> Result<Self>

Compile an expression for evaluation.

pub fn compile_with_aliases( expr: &Expression, columns: &[String], aliases: &[(String, usize)], ) -> Result<Self>

Compile with expression aliases for HAVING clause evaluation.

Expression aliases map expression strings (like “SUM(amount)”) to column indices in the result row. This is used for HAVING clauses where aggregate expressions need to reference pre-computed aggregate results.

Arguments

• expr - The expression to compile
• columns - Column names for the result row
• aliases - Slice of (expression_name, column_index) pairs

Example

// For HAVING SUM(amount) > 100, where SUM(amount) is at column 2
let aliases = vec![("sum(amount)".to_string(), 2)];
let eval = ExpressionEval::compile_with_aliases(&having_expr, &columns, &aliases)?;

pub fn compile_with_options( expr: &Expression, columns: &[String], columns2: Option<&[String]>, outer_columns: Option<&[String]>, expression_aliases: Option<StringMap<u16>>, function_registry: &FunctionRegistry, ) -> Result<Self>

Compile with full context options.

pub fn from_program(program: SharedProgram) -> Self

Create from a pre-compiled program.

pub fn with_params(self, params: ParamVec) -> Self

Set query parameters.

pub fn with_named_params(self, named_params: FxHashMap<String, Value>) -> Self

Set named parameters.

pub fn with_context(self, ctx: &ExecutionContext) -> Self

Set context from ExecutionContext.

PERF: Both params and named_params share the Arc - zero cloning.

pub fn with_transaction_id(self, txn_id: Option<u64>) -> Self

Set transaction ID.

pub fn set_outer_row(&mut self, outer: &FxHashMap<CompactArc<str>, Value>)

Set outer row for correlated subqueries. Accepts CompactArc<str> keys directly to avoid conversion overhead.

pub fn clear_outer_row(&mut self)

Clear outer row.

pub fn eval(&mut self, row: &Row) -> Result<Value>

Evaluate the expression for a row.

pub fn eval_bool(&mut self, row: &Row) -> Result<bool>

Evaluate as boolean (for WHERE/HAVING).

pub fn eval_bool_checked(&mut self, row: &Row) -> Result<bool>

Like eval_bool but returns errors instead of swallowing them.

pub fn eval_join(&mut self, left: &Row, right: &Row) -> Result<Value>

Evaluate with two rows (for joins).

pub fn eval_join_bool(&mut self, left: &Row, right: &Row) -> Result<bool>

Evaluate join as boolean.

pub fn eval_slice(&mut self, row: &Row) -> Result<Value>

Evaluate with a row reference.

pub fn eval_slice_bool(&mut self, row: &Row) -> Result<bool>

Evaluate as boolean.

pub fn program(&self) -> &SharedProgram

Get the underlying program.