import type { BinaryMalloyOperator, FieldSpace } from '..';
import type { ExprValue } from '../types/expr-value';
import { ATNodeType, ExpressionDef } from '../types/expression-def';
export declare class ExprNULL extends ExpressionDef {
    elementType: string;
    getExpression(): ExprValue;
    apply(fs: FieldSpace, op: BinaryMalloyOperator, left: ExpressionDef): ExprValue;
}
export declare class PartialIsNull extends ExpressionDef {
    readonly op: '=' | '!=';
    elementType: string;
    constructor(op: '=' | '!=');
    apply(fs: FieldSpace, op: string, expr: ExpressionDef): ExprValue;
    requestExpression(_fs: FieldSpace): ExprValue | undefined;
    getExpression(_fs: FieldSpace): ExprValue;
    atNodeType(): ATNodeType;
}
export declare class ExprIsNull extends ExpressionDef {
    readonly expr: ExpressionDef;
    readonly op: '=' | '!=';
    elementType: string;
    constructor(expr: ExpressionDef, op: '=' | '!=');
    getExpression(fs: FieldSpace): ExprValue;
}